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Vermont House Uses Only Half a Cord of Firewood

In Ripton, Vermont, this fuel-stingy replica of Chris Corson’s Maine Passivhaus was heated last winter by a small wood stove

Posted on Jun 6 2014 by Martin Holladay, GBA Advisor

When my friend Laura Murphy mentioned that her neighbors in Ripton, Vermont, Chris and Zoe Pike, stayed warm last winter by burning just half a cord of firewood, I was intrigued. So I tracked down the Pikes to learn a few more details about their house.

It turned out — surprise, surprise — that the Pikes’ house was designed by Chris Corson of Belfast, Maine. In fact, the Pikes’ house is a virtual replica of the well-publicized Passivhaus that Corson built in Knox, Maine. (GBAGreenBuildingAdvisor.com has published two stories about the Knox house: Striving for Passivhaus Affordability and Cold-Climate Passivhaus Construction Costs. Chris Corson’s JLC article about the Knox house was titled An Affordable Passive House.)

Chris Corson, the founder of Ecocor, is one of two New England builders — the other is Carter Scott in Massachusetts — who have been justly praised for building high-performance cold-climate homes that don’t break the bank.

A tight thermal envelope with high R-values

The Pikes hired Alex Carver of Northern Timbers Construction to build their house. Construction was completed last fall.

The house sits on a slab-on-grade raft slab foundation that includes 12 inches (about R-50) of expanded polystyrene (EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest.) foam. “Branch River Plastics delivered the EPS foam right to my shop, which is two miles away from the building site,” Carver told me. “We precut the four outside corners. I had to miter the corners, using a combination of hand saw cuts and a hot wire. The house is a rectangle, so that was easy.”

The 14-inch-thick walls are a variation of the Klingenberg wall, with 2x4 bearing walls sheathed with OSB and vertical TJIs attached to the exterior side of the OSB sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. . The TJI bays were insulated with dense-packed cellulose, and the 2x4 bearing wall was insulated with 3.5 inches of Roxul mineral wool, for a total wall R-value of about R-52. The attic is insulated with about 36 inches of cellulose (R-100 plus).

The walls of the Pike house do not have any fiberboard sheathing (the type of sheathing used at the Knox house) on the exterior side of the vertical TJIs. Instead, the walls use a European membrane (Solitex Mento) on the exterior to retain the cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection..

“The most tedious work was the vigilant air sealing and taping,” Carver told me. “It was a challenge.” The work paid off. The Pike house tested at 0.40 ach50, easily beating the Passivhaus airtightness target.

The house has triple-glazed Intus windows with vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). frames. The roofing is steel. For more information on the construction process, see the blog written by Zoe Pike, Passive Solar Homestead. (Zoe's blog does an excellent job of explaining and illustrating how Zehnder's plastic ventilation ducts are connected to the distribution boxes.)

Not much firewood was needed

Like the house that Corson built in Knox, Maine, the Pikes’ house is designed to be heated with a single 12,000 BTUBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules. /h Mitsubishi ductless minisplit unit. “We have a minisplit, but we didn’t turn it on all winter,” Chris Pike told me. Instead, they heated their house with a Morso 3112 wood stove. The stove has a very small firebox that takes 12-inch firewood.

I spoke to Alex Carver, the builder, about the stove. “Chris Corson did not want the Pikes to have the wood stove,” Carver told me. “But Chris Pike was adamant that he lived in a wood lot and wanted to burn wood.”

Chris Pike said, “Chris Corson predicted we were going to burn 1/2 cord of firewood. I told myself, ‘I’m going to put up a cord and a third.’ But we used less than 1/2 cord of firewood for the entire winter.”

I was curious to know how carefully the Pikes measured their firewood consumption. “We stack our firewood on pallets, and each pallet holds a 1/3 cord,” Chris Pike told me. (See Image #4, below.) “At the beginning of winter, we had four of those pallets. We burned one and a half pallets of firewood, along with about half a pallet of construction scraps.”

After Chris Pike e-mailed me some photos of his firewood stacks, I concluded that he measures the firewood carefully.

A cord of seasoned hardwood contains about 24 million BTU, so a 1/2 cord contains about 12 million BTU. If the Pikes’ wood stove has an efficiency of 65%, then the house required about 7 million BTU of heat last winter. (To get the same amount of heat from an oil heating system with an efficiency of 85%, you would need about 59 gallons of fuel oil.)

Learning how to run a wood stove in an airtight house

It can be tricky to operate a wood stove in a very tight house, so I asked Chris Pike if their Morso stove had any problems with draft. “We installed a dedicated air inlet,” he told me. “Morso calls it the ‘mobile home kit,’ because it’s often used when the stove is installed in a mobile home. The air intake goes right to the back of the stove. We installed a short length of metal duct, but the fresh air duct transitions to PVC in the wall.” The 2-inch diameter duct is controlled by a ball valve purchased from a plumbing supply house. [Author's postscript: GBA readers should note that the use of PVC duct in this location may violate code requirements and may constitute a fire hazard. For further information on this topic, see Comments #3, #15, and #17, below.]

He continued, “We also have a Zehnder ComfoAir 200 HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. . When the Zehnder unit goes into defrost mode, it shuts down the outdoor air intake, which can depressurize the house. So we learned to shut off the Zehnder unit — to power it right down — before lighting a fire in the wood stove. I later figured out that the Zehnder has an ‘open fire mode’ that can be engaged instead of turning the unit off. That way the wood stove drafted much better during the initial start. We also learned that our electric clothes dryer will put the fire right out. When the dryer is on, the smoke will back-puff from the stove and the fire will go out. So we never use the clothes dryer when the stove is lit. It’s just a management issue.”

Alex Carver provided another example of the Pikes’ “active management” approach. “The Pikes insisted on having a gas range, and the range hood isn’t vented,” Carver told me. (Their range hood has a recirculating charcoal filter; the kitchen also has an exhaust grille in the ceiling connected to the Zehnder HRV.) “The CO2 levels are being monitored. I was over at the Pikes’ house for dinner a few weeks ago — we were a party of six — and the CO2 monitor was on the counter. Chris noticed that the CO2 levels were rising, so he turned up the Zehnder a notch, and the CO2 levels came down.”

Were the indoor temperatures low?

I wondered whether the Pikes’ low rate of fuel use could be attributed to low indoor temperatures. The answer was no. “When we woke up in the morning, the indoor temperature was about 65 degrees,” Chris Pike told me. “But if the day was sunny, it was 74 in the afternoon.”

Chris Pike was interviewed by journalist Ted Cushman in January; the interview led to a blog post on the JLC website titled “Cold Snap Tests High-Performance Homes.” Chris Pike told Ted Cushman that “bedrooms on the north side of the house run slightly cooler than the sunnier south-facing rooms … but they’re still comfortable.”

Pike also told Cushman, “In the evening, my wife might start a small fire in the wood stove after the kids are in bed, just for us to hang out by. … And by ten or eleven o’clock the fire goes out and we go to bed.”

The colder the outdoor temperature, the earlier the Pikes would light their evening fire. Pike told me, “When the outdoor temperature was 10 degrees or less, we would light a fire in our wood stove in the evening at about 6 o’clock. The next morning, I would look at the weather forecast. If it was going to be sunny, I wouldn’t touch the wood stove. Otherwise we would light a fire in the morning.”

The HRV has a heating element

I asked Chris Pike about his electric bills. “They’ve been running between $75 and $90 a month,” he said. “The Zehnder HRV has an electric heater that draws 700 or 800 watts, so that’s a fairly significant draw when it’s on. It just comes on when it’s cold outside. We could have put in a glycol ground loop instead of using the electric heater, but that would have cost $3,000 to put in.”

I asked whether the Pikes were pursuing Passivhaus certification. “I’m not,” Chris Pike told me. “I have a house that does what I want it to do.” As it turns out, however, the builder, Alex Carver, is planning to pursue Passivhaus certification at his own expense — even if the process costs him thousands of dollars. “We consider it an advertising expense,” Carver told me.

I asked Chris Pike, “If you could build the house again, would you do anything differently?” He responded, “I can’t think of anything. The house has been working great. It’s performed beyond our expectations.”

Construction costs were reasonable, Pike told me. “I like Chris Corson’s approach. As he says, you don’t have to be a millionaire to have a high-performance house. Our house is under 1800 square feet, and we built it for around $165 a square foot, including the well and the septic system, but not the land.”

No radiant heat required

At the end of the construction process, Carver was proud — but he still had a few worries.

“I was very surprised to have that much glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. in a house with no radiant heat in the concrete slab,” Carver told me. “That scared me a bit. When the house was completed in the fall, it took a couple of weeks before the slab finally started warming up. It took a long time to get it up to temperature.” (In a followup e-mail, Carver emphasized that this warming-up process was a one-time event, not something that will recur every autumn.)

After monitoring the performance of the house over its first winter, Carver's worries have evaporated. “I’m very impressed about how the slab is performing,” he said. “For me, what is so awesome is that so little energy was required to heat the house last winter.”

Martin Holladay’s previous blog: “New Green Building Products — May 2014.”

Click here to follow Martin Holladay on Twitter.


Tags: , , , , , , , ,

Image Credits:

  1. Image #1, #3, and #4: Chris Pike
  2. Image #2: Alex Carver
  3. Image #5, #6, #7, #8, #9, #10, #11, #12, #13, and #14 : Zoe Pike
  4. Image #15: Chris Corson

1.
Fri, 06/06/2014 - 10:07

wood stove chimney thermal bridge?
by Zac Blodget

Helpful? 0

How did they run the metal chimney through the roof and outdoors without creating a massive thermal bridge? I've often wondered how this is done.
Switching to PVC on the fresh air side makes a lot of sense, but I'm sure you couldn't do this on the exhaust side.


2.
Fri, 06/06/2014 - 10:21

Response to Zac Blodget
by Martin Holladay, GBA Advisor

Helpful? -1

Zac,
Penetrations through the thermal envelope allow heat flow, and reduce the thermal performance of the envelope somewhat. Neverthess, every thermal envelope has penetrations: water supply pipes, sewage pipes, electrical cables, ventilation ducts, and sillcocks -- not to mention windows and doors.

We make these compromises because of the benefits that these penetrations provide. I could seal you up in a rigid foam box if I wanted, and the box would perform well -- but eventually you would want some fresh air, a glass of water, and facilities where you could relieve yourself. And eventually you would also request a door.


3.
Fri, 06/06/2014 - 11:41

How is a PVC air intake duct anywhere near code compliant?
by Dana Dorsett

Helpful? 0

http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_10_sec006.htm

I doubt PVC is safety agency listed air-intake duct, thus falling under R1006.3:

"R1006.3 Clearance.
Unlisted combustion air ducts shall be installed with a minimum 1-inch (25 mm) clearance to combustibles for all parts of the duct within 5 feet (1524 mm) of the duct outlet."

I've read elsewhere (a previous blog on this site?) than the Morsø combustion air kits are nowhere near air-tight to the firebox, which explains the backdrafting difficulties.

I'm no rabbi, but this installation doesn't look kosher to me.

http://www.greenbuildingadvisor.com/sites/default/files/Pike%20-%20Wood%...

A metal duct with code-legal clearances to the siding & sheathing and metal air barriers at the penetration points, wrapped in rock wool where it penetrates the cellulose might cut it. The thermal bridging of the metal duct penetration might add up to another 5lbs of wood consumption over a cold VT winter, but so be it.

A backdrafted coal into the PVC from a big wind gust can become white-hot once the air-flow reverses, and will burn through PVC like a hot knife through butter. Counting on the fire-retardents in the cellulose to suppress a well-fanned flame for extended periods of time seems a bit optimistic.


4.
Fri, 06/06/2014 - 11:43

Martin
by Malcolm Taylor

Helpful? 0

Very interesting project. I'm a bit confused by the reference to the heating element in the HRV. Isn't that another source of heat? The climate here in the PNW and Vermont aren't comparable, but my electric bill for my Not Very Good House here, including resistance baseboard heat, are about the same as theirs.


5.
Fri, 06/06/2014 - 11:46

Edited Fri, 06/06/2014 - 11:49.

chimney
by Marc Rosenbaum

Helpful? 0

I'm soon to try this in my own renovated house. It's one story. I made the choice (which may be a poor one) to take the smoke pipe out horizontally out through the wall directly behind the stove, to an exterior stainless insulated chimney. I know I'll not get as good of a draft because the chimney is outdoors, but I thought I'd get less air leakage with the envelope penetration through the wall at about 2-1/2 feet above the floor than with a roof penetration, because the wall penetration has less pressure acting on it. We'll see next winter.

My Zehnder 200 also has the electric preheat element for defrost. For the second half of the heating season (late Jan to end of May) the unit used 131 kWh in total and about 70 kWh of that is the preheater.


6.
Fri, 06/06/2014 - 12:05

Edited Fri, 06/06/2014 - 12:13.

true cost?
by Nick T - 6A (MN)

Helpful? 0

I'm intrigued by the price of the home (as an energy eng) - the price per foot is quite high (yet it alludes to not need to be a millionaire...). How do the fit and finishes of this house compare to an 'executive quality' home..? Also if one was to include a modest .3 acre lot what would that come to as a price per foot?

Lets say...50k lot, added in that gets you at 190$ per sq ft. In my neck of the woods that ends up being a very costly house for new construction. New construction in a nice suburb, with a 'very nice' home ends up in the 140-150$/ft mark... Of course the NE is quite a bit higher in costs then MN, but would nice to see that comparison.

Something like "Homes of similar style and acreage (besides efficiency items) are selling for on average 164$/sqft" Which then would allow some sort of investment conclusions (besides just warm and fuzzy feelings about icebergs and our children's children world, which I hope we all love). What would a code (plus a little maybe) built home in that region end up paying per year in utilities? ($1k in heat/cool annually around here for 2700sqft finished approx(+1000unfinsh basemt))

I really like the idea of using a similar design of an existing super efficient home and then also not getting it certified to help somewhat control the amount of unnecessary money spent on the project.


7.
Fri, 06/06/2014 - 12:38

Response to Dana Dorsett
by Martin Holladay, GBA Advisor

Helpful? 0

Dana,
I reported on the combustion air duct's transition from metal ducting to 2-inch PVC deliberately, because this detail caught my attention. When I interviewed one of the owners (Chris Pike) and the builder (Alex Carver), I mentioned the fire risk. Both responded that they weren't particularly concerned about the fire risk.

I'm a journalist who is reporting on the details of this house, as it was built. Like you, I consider the use of PVC at this location concerning. Conceivably, a strong backdraft or a gust of wind could send a hot glowing coal into the PVC duct.


8.
Fri, 06/06/2014 - 13:04

Response to Malcolm Taylor
by Martin Holladay, GBA Advisor

Helpful? 0

Malcolm,
Q. "I'm a bit confused by the reference to the heating element in the HRV. Isn't that another source of heat?"

A. Yes, it is. That's one reason why I asked Chris Pike about his electric bills.

Zehnder documents are rather vague when it comes to providing information on the watt draw and control algorithms for the electric-resistance element in their ComfoAir 200 HRV. One Zehnder document states, "In order to ensure reliable operation even at extreme outside temperatures, an optional integrated, electrical preheater register is available."

Another Zehnder document states, "Fitting the optional pre-heater in the ComfoAir gives the added bonus that balanced ventilation remains intact for longer." This isn't English. I think the document means, "Installing the optional pre-heater in the ComfoAir reduces the amount of time during which the appliance reduces the ventilation rate or ceases operation altogether in cold weather."

When reporting on heating fuel data, it's important to remember that all indoor electrical appliances -- including the HRV, the refrigerator, the television, and the light bulbs -- give off heat that keeps a house warm during the winter. If these appliances were all turned off, either the indoor temperature would drop, or the consumption of firewood would necessarily increase.


10.
Fri, 06/06/2014 - 13:34

Others doing affordable Passive Houses.
by Robert Swinburne

Helpful? 0

Don't forget http://www.gologic.us/ and http://www.mainepassivehouse.com/Welcome.html (Jesper Kruse) as others doing affordable Passive House level projects. (what is it with those Maine folks?)

To Nick T: Here in Southeast Vermont $150/s.f. exclusive of land generally means some level of owner involvement in the construction or run of the mill factory housing or a very large house with low per square foot costs. A recent high end project came in at $270/ s.f. but when I added in the basement area - it cost an additional $20 to finish the basement on a $700k project - the overall cost was reduced to $210/s.f. A good lesson about not using cost per square foot in any but the most vague terms.


11.
Fri, 06/06/2014 - 13:37

Edited Fri, 06/06/2014 - 13:44.

Window Size and SHGC
by Peter L

Helpful? 0

The article mentioned that they used Intus triple pane PVC windows but what are the specs on the SHGC and the window sizes? That center window seems to be pretty large, maybe 6x5?


12.
Fri, 06/06/2014 - 13:46

Response to Marc Rosenbaum
by Martin Holladay, GBA Advisor

Helpful? 0

Marc,
Thanks for the kWh data on your Zehnder; that's useful.

You wrote, "I made the choice (which may be a poor one) to take the smoke pipe out horizontally out through the wall directly behind the stove."

Your parenthetical comment reveals that you understand the trade-offs involved. But I think you may rue the day that you decided to cut a hole in your wall instead of your ceiling.

I've always been a chimney-in-the-center-of-the-house kind of guy, for several reasons. Warm chimneys certainly draw better, as you point out. But more importantly, warm chimneys collect less creosote and need less frequent cleaning.


13.
Fri, 06/06/2014 - 14:05

Response to Robert Swinburne
by Martin Holladay, GBA Advisor

Helpful? 0

Robert,
Thanks for your comments. If GBA readers want to read more about the Maine builders mentioned by Robert, here are some links.

Homes by Jesper Kruse: Two Single-Family Passivhaus Projects in Maine.

Homes by GO Logic:

Michigan Gets Its First Passivhaus

Cold-Climate Passivhaus Construction Costs

A Cohousing Community Readies for Construction

Unity College’s TerraHaus Aims for Passivhaus

Gearing Up for a Passive House Residence at Unity College


14.
Fri, 06/06/2014 - 14:25

HRV frosting / balanced ventilation problems
by Kristopher Steege-Reimann

Helpful? 0

It seems like in a northern climate it could have made sense to specify an HRV that had a core that wasn't susceptible to frost in the first place (or at least didn't have to rely on dampers/electric heating elements that cause imbalanced/restricted ventilation and preheater energy cost).

The added complexity to these units also seem to be reflected in their cost that cause them to cost thousands vs. hundreds of dollars compared to units that are just as energy efficient but don't require defrosting hardware. (I'm guessing the Zehnder unit with heating element cost well over $2,000) Here's a similar house that took care of that issue with an inexpensive (<$600) passive-defrosting HRV unit: http://www.nesea.org/uncategorized/dear-jamie/

Our house uses a similar 90CFM HRV unit (EV90P) that stayed frost free on the coldest winter weeks in Wisconsin this past year and used about 25kWh from Feb-May with a ventilation rate of 30CFM. Also, I imagine the installation cost of some of these complex units are significantly more when you include the additional wiring of the defrost unit and plumbing of condensate lines.


15.
Fri, 06/06/2014 - 17:14

PVC Air inlet
by Alex Carver

Helpful? 0

Ok I hear you all on the air intake. How about some sort of screen which would prevent a large coal from exiting the stove? Assuming we leave the intake as is.


16.
Fri, 06/06/2014 - 19:14

Response to Peter L. (Comment #11)
by Martin Holladay, GBA Advisor

Helpful? 0

Peter,
I have glazing-only information on the windows. I don't have whole-window (NFRC) specs.

The glazing specs are orientation-specific.

Orientation #1 [presumably, east- and west-facing]:
Glazing only:
U-factor = 0.088
SHGC = 0.494

Orientation #2 [presumably, south-facing]:
Glazing-only specs:
U-factor: 0.106
SHGC: 0.62


17.
Sat, 06/07/2014 - 06:49

Response to Alex Carver (Comment #15)
by Martin Holladay, GBA Advisor

Helpful? 0

Alex,
When it comes to fire safety, I'm not inclined to suggest halfway measures or work-arounds. Instead, I suggest that (a) you contact Morso and make sure to follow the company's instructions for installing the outdoor combustion air kit, and (b) study the applicable codes to make sure that the combustion air duct complies with code requirements.

This is a controversial topic. Many stove manufacturers have concluded that it's safer for a combustion air duct to terminate in the vicinity of the wood stove rather than to be connected directly to the wood stove.


18.
Sat, 06/07/2014 - 09:51

Edited Sat, 06/07/2014 - 12:17.

Chimming in
by christian corson

Helpful? 0

For the record. I never lobbied for Not having a wood stove in an PH. I like wood. Biomass makes a lot of sense in Maine ,VT,NH.; largely heavily forested regions with small rural populations. We could take some lessons from the Austrians in this regard. Cut one tree plant three.The Austrians tend to employ biomass regularly in many PH's. Where as the Germans opt for PV.
In our own PH ( enerPHit at 4.95kbtu/ft2yr) We have an airtight wood stove insert with no make up air. All appliances however that would depressurize the house are outside of the thermal envelope and we use a recirc hood in the kitchen. To get the stove lit we open a window light the stove then close the window. No biggy.

On sundays and in the evenings the kids want to help Dad light fires and we snuggle in front of the fireplace and I drink PBR's and we watch football. (we are a classy bunch)
I would not trade fire on the floor of the cave. I ; Ramapithicun as I am, like fire on the floor of the cave.
BUT, in a Passive House or any well built super insulated airtight, resilient, home that has ultra low heating demands a wood stove is NOT needed. A primary heating plant IS needed .
A wood stove IMO can not be considered a primary heating plant from a design perspective.
Practically speaking, of course it can be.

A wood stove in a PH is a luxury. Since it is not needed, it is a 4-5K luxury item that can be bolted on if it fits within the budget. When designing within strict budgets those discussions need to be had.

I calculated the heating demand of the house at 5,820,480btu. I think this is pretty accurate. The difference in this metric v Martin's 7mill ( which is pretty darn close) is the wood.

I predicted a 1/2 cord bases on these calculations with an additional factor for the wood. I am glad I was close and I applaud Chris and Zoe for their dedication to conserving electrical resources.
I hope that minisplit gets fired up this summer!

Metrics for the windows are correct. Uw for this project ranges between .14btu/hr*ft2*F for the smaller units to as low as .12btu/hrft2F for the lager ones.

I concur with Dana and Martin about the PVC inlet.

Chris and Zoe came to me with Alex and wanted to use the Knox house as a basis for designing and affordable PH. This is truly a bigger brother to that house. Chris, Zoe and Alex were fantastic throughout this project. As Alex I worked together to achieve passive house we have become what I consider to be very good friends.

Hats off to you guys.

Nice article Martin! Wood is good.


19.
Sat, 06/07/2014 - 16:43

Electricity Costs
by Kim Kornylo Walton

Helpful? 0

Malcolm Taylor asked about the electricity costs because his household costs seem to be similar for a house that does not perform as well as this one does. I wonder if it is possible to discover the amount of energy that the house used during the colder months (kwh) and how that compares to warmer months. Electricity costs vary from location to location so a dollar amount may be misleading. This would make the energy consumption for supplemental heating question a bit clearer.
Great house! Great house dwellers!


20.
Sun, 06/08/2014 - 01:15

nice stuff ...
by Jin Kazama

Helpful? 0

i don't want to sound pessimistic ( again ! )

please tell me if i am getting it wrong :

~1800 sq ft X 165$ = ~ 300K$ + land

Please list the expenses that brings this up to 300K$ house
I just can't work it out in my head.

Is the price difference of housing from here to USA really that much ?
( here = QC, Canada )

Please do not get me wrong, but when i look at this nice project, i see a 2 story wood shack built using low cost materials ( cellulose, osb etc.. ) no basement, nothing expensive
( i get that it was not the point ..but i'm trying to push my 300K$+ argument )
not especially beautiful in terms or architecture ( aka it feels neutral )

How much will this kind of house worth for resale in 10 years?

Out of my head, it is the kind of building i would see for sale in the high 100K to the low 200K
( ~ 190K - 230K maybe ) but 300K+ land ?

If this would've been built to the code standard, using similar methods and the usa windows ( non PH approved ),
how much would it cost to build it then ?


21.
Sun, 06/08/2014 - 06:14

Response to Jin Kazama
by Martin Holladay, GBA Advisor

Helpful? 0

Jin,
I would be interested to hear the owners, builder, or designer respond to your comments. In the meantime, I'll offer some observations.

You are correct that this house was more expensive to build than one might guess from looking at it. This means that real estate agents and mortgage lenders may not properly understand its value -- a major problem with energy-efficient houses.

Here are some elements of the house that cost significantly more than similar elements of code-minimum houses:

- The 12 inches of sub-slab rigid foam cost a lot more than what is typically installed.

- It cost more to frame the 14-inch thick walls than typical 2x6 walls.

- The triple-glazed windows cost more than typical double-glazed windows.

- The cost of installing R-52 wall insulation and R-100 ceiling insulation was more than the cost of typical insulation.

- The Zehnder HRV probably cost at least $6,000.

- The European membrane (Solitex Mento) and many, many rolls of European air sealing tape are expensive.

Were the incremental costs worth it -- especially considering the fact that the Pikes ended up with a home with no basement, with very simple windows, with a concrete slab floor, and without many aesthetic flourishes? Only the Pikes can answer that question.

The Pikes probably paid at least $350,000 for their house and land. For purposes of comparison, the house in the photo below is on the market in Ripton, Vermont now for $300,000. It is more than twice as big (4,267 s.f.) and has 4 bedrooms. The lot measures 7.5 acres.

I am certain that the house in the photo costs a lot more to heat than the Pikes' house.

.

House for sale.jpg


22.
Sun, 06/08/2014 - 10:32

Response to Martin (post #17)
by Chris Pike

Helpful? 0

At least our non compliant air intake gave Dana a chance to use the rabbi quip! All kidding aside, we discussed the air intake with the chimney installer. Since air sealing was a big priority we wanted to think of a good way to close off the intake tightly when the stove was not in use, which is a majority of the time. He showed us a poorly sealing metal gate valve. We asked him about the PVC ball valve to metal duct and he didn't flinch. Guess he wasn't up on intake air codes.

As Dana said, the Morso air intake is not tight to the stove. I asked the Morso dealer about this when I initially bought the stove. It is by design but he wasn't sure why. As a commenter in a previous post here says, something to do with EPA stoves cannot be completely closed off. I don't have a citation for this but here's the blog post:
http://www.greenbuildingadvisor.com/blogs/dept/qa-spotlight/how-provide-...

The code that Dana linked doesn't mention wood stove, unless manufactured fireplace means wood stove. I can see with a fireplace, manufactured or masonry, where the air inlet is directly to the firebox where a coal can easily be blown into the intake. When you trace the air path on our wood stove, to keep the glass clean and to burn clean, the intake air ultimately enters the firebox from the top.  A coal would have to be lifted up the front of the glass, into a channel over the top, down the back and into the air intake.  There are secondary reburn holes, again at the top of the firebox, that are 1/16".  Conceivably a small ember could make it back with a wind opposing the draft of the 30' of straight chimney.  Then it would land on PVC with internal air temperatures below freezing surrounded by fire retardant insulation.  

I'm a professional firefighter by trade with over 20 years in the service. I have not seen or been able to find any reports where the air intake was determined to be the cause of a structure fire. I can't say that one does not exist. They wrote the code for a reason. The risk is small but is still there. If I can easily eliminate a risk to my family I do it. The metal transition slides off and I now have an easily sealable proximity air source. I may not even use it and try burning this winter as Chris Corson does. Martin, I can send you an updated photo so the focus can be back on how amazing this house is.

I can't say enough how happy we are with the house. This was an especially cold winter up here and all of our neighbors ordered more firewood. I felt kinda bad telling them we haven't gone through even a 1/3 of a cord at the time. Everyone has been amazed. Many thanks to Chris Corson for the design and to Alex for making it happen. Everyone should build like this.


23.
Sun, 06/08/2014 - 11:04

Response to Chris Pike
by Martin Holladay, GBA Advisor

Helpful? 0

Chris,
Thanks very much for the added information on the outdoor air duct that provides combustion air to your wood stove. The details are useful and help us understand the situation.


24.
Sun, 06/08/2014 - 11:06

Updated photo
by Martin Holladay, GBA Advisor

Helpful? 0

GBA readers,
Chris Pike just e-mailed me the photo below, with the title "Updated air intake photo."

.

Pike - Air intake.jpg


25.
Sun, 06/08/2014 - 11:19

Price
by Malcolm Taylor

Helpful? 0

Jin, the per sq footage costs used by mortgage lenders here in the PNW as representing the average house is $150, so 165 is by no means unusual. To my eye the finished house does look more like the projects I design that come in around $130, however that the owners have decided to put that difference into increased performance rather than finishes is surely a legitimate choice.
There definitely is a difference between Canadian and American costs. Look at FHB's Annual Housing Awards Issue if you want a shock.


26.
Sun, 06/08/2014 - 11:27

response to Chris Pike
by Malcolm Taylor

Helpful? 0

You are right. Getting lost in this is that it is a very well built house that performs exceptionally at a price that dispels the idea of Passive Houses being Boutique Green. Well done.


27.
Sun, 06/08/2014 - 13:58

Edited Sun, 06/08/2014 - 14:22.

Construction costs
by stephen sheehy

Helpful? 0

The real monetary value of a house like this is in the money saved every year, for the life of the house.

When we see a per square foot cost of $165, does that include design? Architect fees are typically around 8-12 per cent, money well spent as far as I'm concerned, but still need to be counted.


28.
Sun, 06/08/2014 - 14:52

Less Expensive Alternative to Zehnder?
by Kevin Dickson, MSME

Helpful? 0

A regenerative-style ERV is potentially much cheaper and more efficient than a Zehnder:
http://greenbuildingindenver.blogspot.com/2014/06/the-future-of-resident...

Approximately $1600 for a 3 bedroom house. And a whole lot less scary to look at.


29.
Mon, 06/09/2014 - 12:40

Malcolm Taylor: is 150$
by Jin Kazama

Helpful? 0

Malcolm Taylor: is 150$ including the land ?? that changes the price significantly

I believe we all understand the impact on the building energy consumption .

But, how can you justify for monetary value, the price difference between the new cost
and the resale value ?

I do not believe that this building will gain 30%+ of value solely based on its energy performance in the near future.

Let's quadruple the energy consumption of this building ... that would put it at near 2 full cords of wood!! representing a superb 100-200$ of value saved.
( ~ 225$ using 3.0cop with a mini @ 0.1$/kw/h and 65% stove eff . )

The point here neway is not the performance of the building, as it looks superbly efficient and well built for this kind of system.

The new cost is the problem.

If the owner accepts to pay more for the efficiency , then there is no problem.
But that situation will only represent a very low % of new homeowner who places eco-efficiency before money etc.. ( it is a positive point but not one many can afford )


30.
Mon, 06/09/2014 - 14:59

Response to Jin Kazama
by Chris Pike

Helpful? 0

Jin

We just converted the construction loan to a conventional mortgage. The bank assessed the house at 400K. We have just under 17 acres of useable land that cost 105K. I say useable because we looked a 30 acre lot for 30K. A few acres were flat the rest went straight up a mountain.

We had to find a builder that would build Chris Corson's design. Builders weren't comfortable with the construction method. One wanted to do a double stud instead. Price quotes were still $200-$220 sqft. Alex was willing to take on the project on both fronts of design and cost. We did it.

We could have done it for less if we bought a less expensive lot, did laminate instead of granite countertops, hollow core instead of solid wood doors, cheaper appliances and a few other upgrades. From what I know $165 sq ft plus land is very good for the northeast. We were under budget. The bank would not have agreed to the mortgage if they thought the house wasn't worth it.

IMG_3483.jpg IMG_3485.jpg


31.
Mon, 06/09/2014 - 15:41

Jin.
by Malcolm Taylor

Helpful? 0

No, the land is extra as is the design, although all services, septic and a rudimentary road are included.
I'm not sure that comparing new construction to existing houses that are on the market is all that instructive. Right now the price for used houses around here is well below the cost of building a comparable new one. The two often bear no logical relation to each other.
You would think that if new builds were more expensive construction would slow down until the scarcity in the market drove all prices up. To some extent this happens, but there must be something else in play because there isn't any direct correlation I can see. Proving, yet again, that applying a logical analysis to real estate markets can lose you a lot of money.


32.
Mon, 06/09/2014 - 21:52

Malcolm, used homes... should
by aj builder, Upstate NY Zone 6a

Helpful? 0

Malcolm, used homes... should cost less.... you don't make sense to me.


33.
Mon, 06/09/2014 - 22:01

ok, thanks for the info
by Jin Kazama

Helpful? 0

Have you guys been able to establish some kind of "cost list" ??
Total material price, total labor pricing etc..

Having to chose cheap inside materials in a new house worth 300K$+ is a bit disconcerting to me,
but again my references might be biased .

Please do not believe i am trying to bash your project , only trying to analyze the build and its cost to better understand the relationship between all the different factors.

And i thought that materials were cheaper in US of A than in Canada
( judging from HD website they still are )

Have you made a list of prices for the different components of the building ?
( total material cost, labor cost, professional fees etc.. ?? )

Why do you think other builders were reluctant toward your project ?
Would it be more of a monetary issue or a capability ??


34.
Tue, 06/10/2014 - 08:58

Response to Jin (post #33)
by Chris Pike

Helpful? 0

Jin

Yes, for the construction loan every expense had to be accounted for. The bank required periodic draws with an itemized list to make sure their money was being spent appropriately. Whether it was the windows or a porta potty rental it was on the list. Again, the bank thought the costs were appropriate for our locale. If I walk away from the house they need to know they can sell the house and recover their money. I know I could have moved to southern US areas like the Carolinas and have built for much less. But Vermont is where I want to live. If you're interested in more specific numbers Alex would have better details on individual costs.

As I said, the builders that weren't willing to take on the project either not comfortable with the construction method or were not able to meet the price per square.


35.
Tue, 06/10/2014 - 16:35

EPA wood stove air supply (response to post #22)
by Dana Dorsett

Helpful? 0

From K Willet's post on the other blog piece:

"As I understand it, an EPA stove can't be completely closed off. The various joints and seals in the stove are airtight, but the air supply has to be sufficient to keep the stove burning cleanly"

The reason EPA wood stoves air supplies are not allowed to be completely cut off is due to high particulate & CO emissions potential when brought down to a true smolder condition. Many/most manufacturers deal with this by using a perforation in the draft control valve- even with the valve fully closed there is a minimum cross-section of area for combustion air defined by the size of the perforation, always provided at least a minimum amount of combustion air to limit the depth of smolder.

But that's inherent to the the stove design, not the combustion air ducting, and orthogonal to the how tight the combustion air duct is to the stove. (Except in this case with the addition of an un-bypassed ball valve on the PVC duct the smolder potential is still there even if the draft valve on the stove has the EPA approved minimum bypass.) Other vendors use reasonably air-tight connections between duct & stove on the combustion air kits, and it's unclear to me why Morsø chose to implement it as a (very-close) proximity duct rather than a tight connection. I haven't seen Morsø units close-up to figure out their drafting design, which may (or may not) provide insight to why they did theirs that way. I'm glad that the drafting design is makes it difficult for backdrafting to ever move embers into the air intake duct (this is not universally true for wood stoves.)


36.
Tue, 06/10/2014 - 16:53

Question for Chris Pike: Chimney Envelope Penetration
by Zac Blodget

Helpful? 0

Hey Chris,
I tried this earlier (see comment #1) but Martin's response didn't quite get to my question: How did you handle the chimney / building envelope penetration of your woodstove? Thanks!


37.
Wed, 06/11/2014 - 16:25

Electric HRV
by Tom Gocze

Helpful? 0

Wonderful building, but the electric heater in the HRV system colors the 1/2 cord of wood consumption, as does the electric bill.
All things considered, it is a fine home.

As one who sells and uses a lot of foam, is anyone else a little concerned about 12 " of foam under the slab and the potential for critters to move in?

I am not saying it is a bad thing, but if one is building an R-50 floor system, why not move it up off the ground to minimize the hidden pathways of insects and rodents. This foundation scheme has to last for a very long time. Plastic foam is inert, but one would have to imagine a time when some nuclear medicine is needed to knock back some sort of infestation in 2, 5, 10 or 20 years.


38.
Wed, 06/11/2014 - 17:36

Spinning numbers
by jim blodgett

Helpful? 0

I'm wondering if the 1800sq ft is measured outside framing? Or is it inside the exterior walls? At 14" thick, it matters, and here in Western WA building departments measure from the exterior.

Another thing - all this talk about cost/square ft - according to Chris Briley and Phil Kaplan's "Green Architect's Lounge" podcast (don't remember which one, they're all worth listening to) initial construction costs only account for...what was it...11%?, 15%?...of the total cost of owning and operating the average home over it's life. Pretty shocking.

But things have to change. We can't keep stifling advances in our building techniques based on initial construction costs. Maybe it's time to look towards longer mortgages, I don't know. But I do believe the value of these well built homes is over their lifespans, not necessarily how well they hold their resale value, or fit into common bank lending metrics.


39.
Wed, 06/11/2014 - 19:15

Edited Wed, 06/11/2014 - 19:23.

Comments
by christian corson

Helpful? 0

To Tom G.- I am not sure how the electric post heater colors things? Nor am I sure what is so outrageous about the electric bill as some other posters have mentioned. It is impossible to model occupancy behavior. Dollars are NOT a metric for energy consumption. The post heater a 500 dollar bolt on appliance is used solely to temper incoming air in extreme conditions. It is a back up heating plant that takes the place of electric baseboard heat as a secondary heating source at a fraction of the cost. I would be surprised if it was even on at all in this house. That being said it is not a perfect devise. I could write a blog on pros and cons of redundant heating methods in PH's.

The foam is type 9 or 29 ( depending on who you talk to) Geofoam EPS. It is infused with boric acid and is not not only pest resistant but also fire resistant. How long does that treatment last below grade? Good question. Nobody knows. I mean really knows. Alternatives, foamglass, foamglass aggregate at 1"minus (not available in the US) or building on piers. I have been working through this for 5 years and foam is still the most cost effective IMO. This will and should change soon....i hope. Working on it.

et al......................COST......................Investing in a home is just that. An investment. For the vast majority of us, it is the single largest capital investment we make in our lives. For some that investment is made more than once. Family's have a way of growing( we have that going for us).

Investments need to be made upfront, not on the back end. Investing in a super insulated, airtight, mechanically ventilated home , that is comfortable to live in and healthy at the same time, is just a no brainier for some, for others it is a different story.

I agree with Jims Bloggetts comment " things have to change. We can't keep stifling advances in our building techniques based on initial construction costs" This is one of the tenants of our mission as a company.
However, longer death pledges are not the answer.

The answer is far more complicated that . Starting with a total cultural shift in what we perceive as important, and ending with redefining the culture and best practices of a construction industry, that has not evolved in 50 years. Can you imagine driving to work in a 72VW bug on the 405 in cali? Or any other modern situation? This again could be a blog post.

Energy prices increase at a rate of 5.68% annually ( DOE). This exceeds cost of living increase's. A larger problem is that energy prices do not behave in "averages" they spike and fall, spike and fall (another blog post) . In 2008 we went from 45-90$/barrel for crude. That will happen again and again; and more and more frequently as this finite resource continues to be consumed by an endlessly growing (and way more complex global economy) than I grew up with. It was already bad then. #70-80's

i'll sum with a statement and then a question then a statement:

I live and work and raise my family in Maine. We have not only one of the oldest existing housing stocks in the country but one of the oldest population's as well.
80% of New England heats with oil ( Diesel fuel)

What happens to the value of the existing housing stock when energy cost's exceed the the means of homeowners to pay them?

My grandfather taught me to buy the best tools that I could afford, to take care of them, and to use them carefully, diligently, and patiently.

Invest wisely. Invest in the best that you can afford to. Have respect and care for that investment, and don't expect immediate returns, the universe just doesn't work like that.


40.
Thu, 06/12/2014 - 07:38

More comments
by Tom Gocze

Helpful? 0

Hi Chris,
Thanks for your comments. I do not disagree with any of them.
Having lived in Maine for 40+ years, anyone in New England understands the cost of living with old housing stock.
My old home in Searsport has been retrofitted to R-65 with polyiso foam and heats with a good mood.
I guess about half of my heating load for most of the year is from electric use waste heat.

My comment about heating loads is based by the fact that the inherent electrical usage will become part of the heat contribution to the home. There is always that anecdotal aspect to comparing projects.
Certainly a 700w heater is of some consequence.

While I admire the 12" foam foundation base, my concern is if any compromise comes of that thickness of foundation foam, there are could be major structural issues.
Hopefully borates will do the trick, but as you say, we just do not know.
It is certainly the most cost effective way to get that high insulation value, but I wonder if that would be acceptable south of the Mason-DIxon line where foam in contact with soil is not an accepted practice.

Unfortunately, there has been some reports of ants and termites in borate treated materials. I hope that was a fluke. I am sure you do too.

All things considered, an important project that people should learn from.
Tom


41.
Thu, 06/12/2014 - 10:25

foundation foam in slightly warmer climates?
by Hallie Bowie

Helpful? 0

Since these houses are in the really cold areas of Maine & Vermont, my understanding is that termites and carpenter ants are less of an issue. Would you make the same choices with the foam in contact with the ground in zone 5, such as northeast Ohio? We aren't prime insect territory, but termites do happen here.


42.
Thu, 06/12/2014 - 11:53

Response to Chimney penetration and Electrical usage
by Chris Pike

Helpful? 0

Zac, the chimney installer used what I believe is called a fire stop spacer at the envelope penetration. There is also an attic insulation shield.

For questions about our electrical usage, we have a SiteSage monitoring system that was installed March 4th by Efficiency Vermont. It monitors each circuit individually. The HRV used 146 kWh in March. April 35 kWh and May was 28kWh which correlated to outdoor temps. The HRV draws about 40 watts durning normal use, setting #2. The unit has four speeds (absent, 1, 2 and 3). 3 is used when cooking, showering or other times when a boost is needed. We set it to 1 or absent if we're not home. When the heating element is on, the draw was recorded at just under 800 watts. We had a data logger monitoring CO2, humidity and indoor temperature. The CO2 monitor helped us tune in our HRV usage. The last 30 days with moderating outside temps the HRV cost $4 to run.

Some things we learned with the electrical monitoring system:

Our old stand alone upright freezer is never turning off. It's supposed to cycle. It is constantly drawing around 100watts costing about $13 dollars a month. We need to replace it with a efficient chest type freezer, predicted to cost only $6-$7 a month.

My wife has a home office. The computer peripherals were drawing a minimum 80-100watts mostly in standby. More when functions like printing were actually happening. We now unplug items that we don't use often like the printer. But internet and back up systems cannot be shut down. About $15 to $20 a month.

We have two young kids. Most every night one of them gets up to use the bathroom and leaves a trail of left on lights. We have all LED lighting, it's not a lot of usage but it still drives me nuts.

There definitely are places where we can get the electrical bill down. We have an electric dryer but we mostly use a clothesline. Like Chris Corson said, it has a lot to do with occupant behavior.


43.
Thu, 06/12/2014 - 11:57

"...has not evolved in 50 years"
by jim blodgett

Helpful? 0

(quote from christian corson in cooment #39)

But they have. Building practices have clearly evolved over the past 50 years. But things change slowly in an industry that produces something (houses) that last far longer than the original mortgage, or builder's career, or original homeowner's life.

The thought is deeply ingrained in me "well, it will last my lifetime, that's for sure". As if that should be "good enough", some measure of quality. But it's not. Over 40 years I've been at this and it seems like only yesterday I started. Those carpenters who built all that "old housing stock" in Maine? I bet for the most part they were doing their level best, according to the standards of the day, and that's what you and I have to do today.

We have to make tough choices what to invest in initially, but I agree that the shell and thermal boundry are great places to start.

But there also has to be a cultural shift in how we view homes. At a minimum they should last 200 years (like many of those old places up your way). We have no way of forseeing how homes will be lit, or heated, or cooled 200 years from now. But the bones should remain strong and the shell should be easilly maintained so as to protect those bones.

And the true "cost" of home ownership over that 200 years should not be higher than average so that the original building can have more curb appeal, stimulate more potential buyer's egos, resell at a profit within 10 years.

A good start would be a cultural shift in thought about what constitutes "good home investment". And thanks to the internet, this too is evolving as we exchange ideas from far flung locals.

Evolution is slow in our industry, no question. But evolve we have, and those building long after you and I are gone will continue to innovate and change. I just hope to leave something that someone with similar values will respect when they tear into it 100 years from now and think "...yeah, well, at the time these folks did the best they knew how. Not what we'd do today maybe, but for it's day..."


44.
Thu, 06/12/2014 - 14:34

Response to christian corson (#39)
by Dana Dorsett

Helpful? 0

"80% of New England heats with oil ( Diesel fuel)"

Not even close to fact.

According to EIA data, in the northeast heat (with NY/PA/NJ included) more than half of all homes heated with natural gas:

http://www.eia.gov/todayinenergy/images/2013.10.08/map.png

Maine's fraction of homes heated by oil is about 77%:

https://wiki.colby.edu/download/attachments/10027724/ES493_EC_Heating+Fu...

https://wiki.colby.edu/display/stateofmaine2008/State+of+Energy+and+Clim...

But Maine is sparsely populated compared to neighboring NH, where the fraction is only 47%:

http://nhpr.org/post/staying-warm-granite-state-guide-home-heating-fuels

http://mediad.publicbroadcasting.net/p/nhpr/files/201310/NH_fuels.png

In (even tinier population) VT, heating oil has less than a 60% share:

http://apps1.eere.energy.gov/states/charts/home_heating_sources_vt.png

VT has recently been heavily subsidizing cold-climate mini-splits for those heating with oil & propane. That program is soon to become expanded, pending signature of a recently passed legislative amendment.

In MA ,RI, & CT the gas grid is more developed, and the number of houses greater, but natural gas is the dominant heating fuel in those states. Even before crude hit $100/bbl heating oil's share in MA (the most populous New England state) had drop to 1/3, and since 2009 it's been dropping faster:

http://www.worldenergy.com/wp-content/uploads/2014/01/House-Heating-by-F...

Oil is DEAD as a heating fuel. To sustain the current levels of oil production requires increasing tight-oil production to increase just to stay even (let alone grow), which has a price floor of about $75/bbl to remain profitable. Oil is currently trading at $100/bbl. Heating oil tracks crude prices fairly closely, so the price floor of heating oil is going to be about $3/gallon, which is far more expensive heat than ductless mini-splits.

As a region, the raw economics are favorable to rapidly displacing heating oil & propane with high-efficiency ductless.

http://www.rmi.org/cms/Download.aspx?id=10410&file=2013-05_HeatPumps.pdf...

But in Maine wood pellets (stoves & boilers) and cord-wood are is also viable fuels for many.

Energy price inflation broadly cannot sustain year-on-year 5%+ levels- the rapidly falling price of PV solar (and grid storage) may even induce broad energy price deflation before the year 2030, according to Sanford Bernstein analysts, and both Barclays & CitiGroup seem to concur. (These are investment bankers, not green-power cheerleaders.) That's not to say it isn't worth building higher performance houses- quite the contrary, but the issue of space heating affordability in older lower performing homes is more about replacing the incumbent space heating fuels with existing technology & sources that is already less expensive. Since 2002 the price of oil has quadrupled, and there aren't any credible scenarios for that to turn around. But in the same period the cost of PV solar energy has dropped by over 60%, and is continuing to drop. Wind power has also had significant cost reductions, with year-on-year reductions in lifecycle-output cost, though not as dramatic as PV.


45.
Thu, 06/12/2014 - 15:46

Another 1/2 cord a year home
by Fred Greenhalgh

Helpful? 0

FWIW my wife and I live in a 500 sq. foot SIPs octagon (one large room yurt-inspired floorplan) and burn 1/2 cord or less per year. We are off-grid so mini-split is not an option and it is in fact more efficient to open up windows for ventilation than run HRV through most of the winter. Ours is no fancy designed home, just small, and we self-financed and built it ourselves. No especially awesome windows or doors, but, the SIPs (Winter Panels) do a lot to keep it cozy inside. If we fill our fire box too much it'll be 80+ degrees in the wintertime.

- Fred


46.
Thu, 06/12/2014 - 16:10

Response to Fred Greenhalgh
by Martin Holladay, GBA Advisor

Helpful? 0

Fred,
What is your climate zone or location? What is your typical minimum winter temperature?


47.
Fri, 06/13/2014 - 11:24

We're in Maine
by Fred Greenhalgh

Helpful? 0

Reply to Martin - Whoops, guess knowing temp zone would be important! We are in Southern ME, York County, so I would imagine similar temps to the people featured in this article. We are inland from the coast so typically experience more snow and more bitter temps.

As you know we all had a 'propah Maine wintah' this year, we are nerds with our solar PV / off-grid usage (by necessity) but not as strict monitoring wood consumption. But, anecdotally, I remember one night we had the house night and warm (75 or so) and so did not stuff the firebox and let it go out overnight. When we woke in the morning, it was chilly for us (62'ish) and when I checked our outdoor temp (remote temp sensor) it was -15F outside. Oh. So then I lit up a fire.

We installed an outdoor wood-burning sauna which we run once a week. We literally will consume more wood in that sauna than we do heating the house the rest of the week, and indoor temps are never below 65F.

- Fred


48.
Fri, 06/13/2014 - 11:27

Update to a comment in post #44
by Dana Dorsett

Helpful? 0

Where I wrote:

"VT has recently been heavily subsidizing cold-climate mini-splits for those heating with oil & propane. That program is soon to become expanded, pending signature of a recently passed legislative amendment."

Apparently it has been signed:

http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/heat-...

It remains to be seen the level of subsidy, and for whom, and which models would qualify. In prior years it was only for those heating with propane or oil, and only the -FExxNA Mitsubishi or -xxRLS2-H Fujitsu or the Daikin Altherma air-to-water hydronig system, to the tune of $1000 rebate for the first unit, $700 for a second.

There is greater value to the utility AND the ratepayers to subsidize retrofits for those heating with resistance electricity, since that reduces the grid load. Under the amended rules those heating with electricity (and natural gas/biomass) will have access to the subsidy as well.

Since VT has NO fossil-fired power generation large enough to fall under the recent EPA carbon emissions rules (the only state exempted!), and electricity demand in VT is shrinking dramatically under recent efficiency efforts, this is a pretty green move!


49.
Tue, 06/17/2014 - 08:44

Indoor humidity
by David Metzger

Helpful? 0

I'm really curious what the indoor relative humidity readings are in this house right now. We've had a pretty wet and cool spring in the northeast and I've discovered in my own very tight, new cottage in upstate New York indoor humidity readings of 60-70%. People have to breathe right? So I'm running the HRV 20 minutes on 40 minutes off, the minisplit is off because the indoor temp is a very comfortable 68-70 degrees--and you can forget the "dry" mode in the minisplit--with these conditions it will just reduce the indoor temp thereby increasing the relative humidity. It seems like in the "shoulder seasons" in the northeast, when you don't need heat or ac--which must be close to a half year--a stand alone dehumidifier seems to be the only solution for keeping indoor humidity levels to a point that you won't have mold or comfort issues. Could someone please address this? And if the case is that a dehumidifier is essential, they take energy to operate and that should be factored in as well for energy consumption.


50.
Tue, 06/17/2014 - 13:13

Edited Tue, 06/17/2014 - 13:16.

Response to David Metzger
by Martin Holladay, GBA Advisor

Helpful? 0

David,
If you want to lower your indoor humidity by operating a ventilation system, all you need is for the outdoor temperature to be cool (which you claim it has been). "Cool and wet" is almost as good as "cool and dry" when it comes to ventilation, because cool air doesn't hold much moisture. (Check out the psychrometric chart.) So just ventilate your problems away -- especially at night.


51.
Wed, 06/18/2014 - 09:39

Edited Wed, 06/18/2014 - 12:33.

Indoor humidity
by David Metzger

Helpful? 0

I wish is was that easy to "ventilate your problems away." In tight houses in Upstate NY, climate zone 6a, my real-life experience begs to differ. That's why I was curious to hear from the folks spotlighted in this article.
I realize the article is about using a tiny amount of fuel to heat their home in the winter, but isn't the bigger story always about energy consumption? Besides, we're beyond the heating season now and on to the more complicated season: Spring. People building passive houses can always brag about how little they spend on fuel in the winter, but nobody ever talks about the shoulder seasons and managing indoor humidity when there is little differential between the inside and outside air temperature and generally high humidity outside.
I took your advice and ventilated (HRV set to high) last night. The indoor humidity shot up to 73% by this morning (up from 63%) and the temperature remained a steady 72 degrees indoors. Comfortable, but moist. So the question is, how much indoor moisture is acceptable to live with, and for how long before it becomes a problem? In the winter, one can always live with a little less heat, but in the Spring--in a super tight house--one should probably not live with too much moisture. We've heard over and over how bad that is. This time of year ventilation brings in excess moisture. I know this because if I turn off the HRV, the humidity goes down, but then I can't breathe :) So it seems like mechanical dehumidification is the only solution. And that's never talked about. It's not even in the letters HVAC. And not only does it use energy to run, it raises the indoor temperature.
Perhaps this could be a topic for another article. How ironic that a house could require little energy in the winter only to use more in the temperate months to keep the indoor air fresh and dehumidified--while people in leaky houses are spending nothing!

BTW, Here's my cottage: https://www.airbnb.com/rooms/1997730


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