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5 Helpful?

Green Building for Beginners

Are you are embarking on a construction project, but still uncertain about how to make your home green? Here is some guidance.

Posted on Apr 19 2013 by Martin Holladay

Green building websites can be confusing. One site might tell you that a green home should include spray foam insulation, a tankless water heater, and a geothermal heating system. After you’ve absorbed this advice, you visit another website, where you learn that spray foam is a dangerous petrochemical, tankless water heaters are overpriced gadgets, and “geothermal” systems aren’t really geothermal.

Eventually someone tells you that you can usually trust advice from Green Building Advisor. After reading a few articles, you start to feel more comfortable. But it only takes a few clicks to end up deep in a thicket, even here at GBA. In no time at all, you are stumbling again.

One GBA article explains that a good way to ventilate your house is with a central-fan-integrated supply ventilation system. Hunh?

Another article advises you to aim for 1.5 ach50. What’s that?

Still another article talks about a type of insulation that is air-impermeable but vapor-permeable. At this point, you’re probably tempted to go back to the website that told you to buy a tankless water heater. At least that advice was easy to understand.

Don't give up just yet

But still, you keep on studying. This type of reading is painful, like learning ancient Greek, but you know that there’s a prize at the end of the tunnel: someday, you’ll finally understand Homer’s wine-dark sea — or at least be able to talk to your builder intelligently.

So you practice pronouncing “polyisocyanurate,” and then you go to your local lumberyard and order some from the guy behind the counter. He answers, “Poly what? Never heard of it.” (This actually happened to me a few years ago.) At that point, you don't trust any information found on the web, and you're probably ready the throw in the towel. And I don’t blame you.

Let’s start at the beginning

In this article, I’m going to aim my advice at typical homeowners (or would-be homeowners) rather than designers or builders. I’m going to assume that the readers of this column are basically starting from scratch when it comes to construction knowledge.

I’m also going to assume that you want to build a new home or renovate your existing home. Where do you start?

If you are planning to build, and you want your home to be energy-efficient and green, here are some basic principles to get you started:

  • Ideally, a green home is small. If you follow good design principles, you can make a small space attractive, durable, and eminently livable for your family.
  • The most important way that you can improve the energy efficiency of a home is to reduce air leakage. You are unlikely to end up with a tight house unless you choose a designer who understands the need for airtight construction methods, and unless you choose a builder who has already built a tight home that has been tested with a blower door.
  • The second most important way that you can improve the energy efficiency of your home is to specify insulation with a higher R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. than the minimum values required by your local building code.
  • Almost any kind of insulation can be made to work, although some types of insulation — most notoriously, fiberglass batts — are difficult to install well and usually perform poorly. Among the most popular insulation materials specified by green builders are cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection. and mineral wool insulation. For certain applications, it’s hard to beat rigid foam or spray foam, although some green builders try to minimize the use of foam insulation products.
  • The third most important way that you can improve the energy efficiency of your home is to specify windows with the right type of 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.. At the risk of getting too technical, that means that you want windows with a lower U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. than run-of-the-mill windows. In hot climates, you should choose windows with a low solar heat gain coefficient(SHGC) The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. (SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.) for your east and west sides. (Hot-climates designers should try to keep west-facing windows to a minimum, or include a wide porch on the west side of the house.) In cold climates, you should choose windows with a high SHGC, especially for your south side. These numbers — U-factor and SHGC — can be found on most window labels.
  • If you have followed the above principles, your heating and cooling needs will be minimal, so you won’t need an expensive heating or cooling system. That’s why you probably won’t need a ground-source heat pumpHome heating and cooling system that relies on the mass of the earth as the heat source and heat sink. Temperatures underground are relatively constant. Using a ground-source heat pump, heat from fluid circulated through an underground loop is transferred to and/or from the home through a heat exchanger. The energy performance of ground-source heat pumps is usually better than that of air-source heat pumps; ground-source heat pumps also perform better over a wider range of above-ground temperatures. (sometimes called a geothermal system) or a radiant floor distribution system.
  • If your home includes forced-air ductwork — most homes do — the ducts must be located inside your home’s thermal envelope. Do not allow your designer or builder to locate ducts in a vented crawl space or a vented attic.
  • Tight homes need a mechanical ventilation system. There are three basic choices: an exhaust-only system consisting of one or two high-quality bath fans; a supply ventilation system that introduces a little fresh air into your furnace ductwork; or a balanced ventilationMechanical ventilation system in which separate, balanced fans exhaust stale indoor air and bring in fresh outdoor air in equal amounts; often includes heat recovery or heat and moisture recovery (see heat-recovery ventilator and energy-recovery ventilator). system that includes a heat-recovery ventilator (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. ) or an energy-recovery ventilator (ERV(ERV). The part of a balanced ventilation system that captures water vapor and heat from one airstream to condition another. In cold climates, water vapor captured from the outgoing airstream by ERVs can humidify incoming air. In hot-humid climates, ERVs can help maintain (but not reduce) the interior relative humidity as outside air is conditioned by the ERV.). Any one of these systems can work well. At this point, you don’t have to understand all the ins-and-outs of these three ventilation systems, but eventually you may want to read up on these different ventilation strategies.
  • When it comes to domestic hot water, designing a compact piping arrangement — with a layout that places your bathrooms as close as possible to your kitchen — matters more than the type of water heater you choose. Installing a solar water heater rarely makes financial sense.
  • At least two aspects of your home are hard to change: the height of your ceilings and the width of your roof overhangs. Make sure that your ceilings are high enough (in my opinion, a 9-ft. ceiling is almost always preferable to a 7-ft. ceiling) and that your roof overhangs are adequate (in my opinion, wide overhangs are usually better than stingy overhangs).
  • You can choose trendy interior finish materials like bamboo flooring or earth plaster if you want, but the decisions you make on interior finishes are unlikely to matter very much from an environmental perspective — especially compared to energy efficiency decisions.

Questions for your designer or architect

Before you choose a designer or architect, ask the candidates a few questions:

  • What makes a house green? (A designer who mentions things like “keeping the house small” and “keeping energy bills low” is on the right track. A designer whose first answer is “choosing green materials” may not be the one you want to hire.)
  • What design elements contribute to energy savings? (Good answers include “paying attention to airtightness” and “making sure that the walls and ceilings are well insulated.” You don’t want to hear, “Choosing a furnace or air conditioner with a high efficiency rating.”)
  • When you draw plans, do you indicate the location of a home’s air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both.? (If the designer says “yes,” that’s a very good sign. A designer who says “no” may be a good designer, but he or she will probably require some hand-holding and education.)

Questions for your builder

Of course, you want to choose a builder with a good reputation and many satisfied clients. But you want more than that: you want a builder who understands house-as-a-system principles and who has paid some attention to building science issues. Here are some questions for your builder:

  • Have you ever built a home with an airtightness goal included in the specifications?
  • How many homes have you built that were tested with a blower door? What were the results? (One way that builders report blower-door results is in “air changes per hour at 50 pascals.” This metric is often written as “ach50.” Results of 1.5 ach50 or lower are quite good. Results of 1.5 to 2.5 ach50 aren’t bad.)
  • What’s a good way to address thermal bridgingHeat flow that occurs across more conductive components in an otherwise well-insulated material, resulting in disproportionately significant heat loss. For example, steel studs in an insulated wall dramatically reduce the overall energy performance of the wall, because of thermal bridging through the steel. through the studs? (Good answers include “we can build a double-stud wall” or “with exterior rigid foam.” A not-so-good answer would be, “What’s thermal bridging?”)
  • Do you install a polyethylene vapor barrier on the interior side of your walls? (In locations that are more than 200 miles from the Canadian border, the answer you want to hear is “no.”)

Red flags

If your designer or builder suggests any of the following features, consider the suggestion a red flag:

  • Forced-air ductwork installed in an unconditioned vented attic
  • Fiberglass batts to insulate the interior of a basement wall
  • Spray foam insulation that doesn't meet minimum code requirements (because “R-20 spray foam performs better than R-38 fiberglass”)
  • Adhered “manufactured stone” veneer over OSB wall 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.
  • Recessed can lights in an insulated ceiling
  • Pull-down attic stairs in an insulated ceiling
  • Tongue-and-groove boards as the finish material on a cathedral ceiling insulated with fiberglass batts (unless gypsum wallboard has been installed first)
  • A powered attic ventilator (that is, a fan to keep your attic cool).

My advice

It’s easy to get sidetracked by opinionated designers and builders. But everybody has opinions, including me. Here are a few basic principles — yes, these are just opinions, too — that I advise you to adhere to if you want to build an energy-efficient home:

  • Aim for a compact shape with few ells, bays, and bump-outs.
  • If possible, orient the long axis of the house in an east-west direction.
  • In most U.S. locations, it makes sense to include more windows on the south side than the north side. (This advice doesn't apply in hot climates or the Southern hemisphere, however).
  • Spend some time researching window specifications; choose glazing that is appropriate for your climate.
  • Hire an engineer or a certified energy rater (rather than an HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. contractor) to determine the size of your heating and cooling equipment.
  • Locate all forced-air ductwork inside the home’s thermal envelope.
  • Include a mechanical ventilation system.
  • Do not install any recessed can lights in an insulated ceiling.
  • Insist on a blower-door testTest used to determine a home’s airtightness: a powerful fan is mounted in an exterior door opening and used to pressurize or depressurize the house. By measuring the force needed to maintain a certain pressure difference, a measure of the home’s airtightness can be determined. Operating the blower door also exaggerates air leakage and permits a weatherization contractor to find and seal those leakage areas.. If possible, include an airtightness goal in the job specifications.

Learning more

The purpose of this article is to get you oriented to a few basic topics, and to prevent any major mistakes that will be expensive to fix later. Of course, there is a lot more to learn on the topics mentioned here; the more you learn, the more you may develop strong opinions on topics like insulation materials, window specifications, ventilation equipment, or heating systems.

If you take these topics in small bites, using the resources on the GBA website to research one topic at a time, you may be able to make the transition from a confused homeowner to a building science expert. Even if you abandon your self-education efforts halfway through your project, at least you’ll have enough knowledge to negotiate intelligently with your designer and builder.

Martin Holladay’s previous blog: “Insulating Low-Slope Residential Roofs.”

Click here to follow Martin Holladay on Twitter.

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Image Credits:

  1. Latin American Technical Education Foundation

Apr 19, 2013 7:14 AM ET

by Dan Kolbert

I think someone finally spelled out the PrettyGoodHouse.

Apr 19, 2013 7:33 AM ET

Edited Apr 19, 2013 7:35 AM ET.

Nice Job
by Carl Seville

Concise overview of where to start. I always like to say that green building is all about the process - materials are secondary.
You did a great job of avoiding your cold climate bias with one minor exception - your suggestion to minimize windows on the north side of the house. In hot climates, I believe that north windows are a good thing - natural light and minimal heat gain.

Apr 19, 2013 8:58 AM ET

Response to Carl Seville
by Martin Holladay

Thanks for the feedback. I have edited my advice on north-facing windows in light of your comments. I always appreciate hearing from Southern experts like you.

Apr 19, 2013 10:46 AM ET

City of Vancouver Design Guide
by Aaron Gatzke

The city of Vancouver has published a passive design guide that is good starting point for beginners. It has information in there that I have not seen elsewhere. While the guide is geared to Vancouver, most of the design principles apply to all.

Apr 19, 2013 12:00 PM ET

Great tips
by Steve Knapp CZ 3A Georgia

Thank you, Martin. As someone who is in the process of bidding a new "green" home, I really appreciate this distilled version of what to do on this type of project to minimize the misadventures.

Apr 19, 2013 12:50 PM ET

What i like the most of this
by Jin Kazama

What i like the most of this article is your "entre en matiere " .... hahaha
u have a way to setup the article ... hahaha

nice one again :)

and i do enjoy your "north" bias !!!

Apr 19, 2013 2:07 PM ET

Edited Apr 19, 2013 2:10 PM ET.

Siting and beyond the build
by Paul W

Another really good article Martin. My biggest objection is that it just covers one phase of a multi-phase project. I'd like to see more discussion of the importance of picking a good site, both for solar and environmental issues, but also for longevity of the project, which might mean a trip to the municipality planner's office to see what the long term development plans are for that area.

I'd also like to see discussion of what comes next. After you find your builder who is wonderful at designing a tight, well insulated, low energy using house, how do you pick materials for various components and elements? There are standards for everything, sure, in many cases multiple standards. Sometimes they overlap, sometimes they conflict. Some manufacturers don't meet standards, or only meet some of them, and yet others don't participate even though they probably exceed standards (point in case, I was just looking at the website, and poggenpohl cabinets are not listed as being rated, some of the more expensive cabinets on the market. Doors are an example of multiple standards, many doors are rated for either insulation value, hurricane rating or security abilities, but not many seem to be rated in all). Figuring out which standards are important for each component of a home is simply overwhelming, let alone resolving conflcts and all the other issues.

Finally, some tips for post-build maintenance. How do you make sure that you keep your house running at a low energy use level.

Apr 19, 2013 2:28 PM ET

Edited Apr 19, 2013 2:43 PM ET.

Response to Paul W
by Martin Holladay

You're right -- this 1,800-word article doesn't cover every aspect of residential construction.

Your suggested topics -- choosing a good building site, material selection, and maintaining a home to assure energy efficiency -- are all good ideas for upcoming articles.

In the meantime, at least two of the topics -- choosing a good building site and material selection -- are covered in the GBA Encyclopedia.

Here are a few articles on site selection:

Siting with the Sun

Location Efficiency Trumps Home Energy Efficiency

Location Efficiency

Reduce the Need for Driving

The GBA Encyclopedia has information on materials selection in a great many articles, including the articles on foundations, walls, windows, roofing, siding, insulation, and plumbing.

Apr 19, 2013 6:32 PM ET

Great elevator speech
by Marc Labrie

Thanks Martin for this one pager. I'll be pointing many newbie to this page so they understand the concept behind how to plan a better house...

Apr 19, 2013 11:55 PM ET

Thanks for the good advice.
by Vince Caruso

Climate change is now. This site's noble effort could be a big step back from the brink if we have enough participation.

Insulation and air sealing is clearly a major key to the success, but,

With all this talk of spray foam insulation inside the walls of homes, exposing homeowners to the off gases we really need some discussion of Toxicology of these exposures over time in very tight homes. Isocyanates for instance are a known as a 'bad actor in human exposure' in the field and should not be taken lightly, just to name one. When I see walls and ceilings sprayed full and covered in drywall, and it called 'Green', I get very worried for the occupants. EPA is taking a second look now as they should.

The initial reports on some of the compounds are very troubling and need to be discussed, and more research done before we have such widespread use. This will be very difficult if not impossible to mitigate not to mention the long term exposure health effects in 'super tight' houses.

Thanks for a Great Site.

Apr 20, 2013 6:27 AM ET

Edited Apr 20, 2013 6:39 AM ET.

by JP Jon Pierce

You keep it easy enough Martin
thank you again

interesting that there are so many different word phrases playing on the marketing of all the things
that you addressed
I would like to identify
that if we have a tax credit with geothermal using the term for Earth Heat geo thermal and deep ygeothermal only but for masses of folks retrofitting to New...its all geothermal

I have had a paradigm shift in discussing any projects like these with deregulated applications of energy
it's a better utility bill first
then a better building
Best air Distribution of heat with cooling and
100 percent heat recover to domestic making of instant or regular hot water
whenever possible in the air conditioning mode if air conditioning is used

n making 2700 square feet into 3700 was with only a half inch of spray on foam to improve the tightness and all the rest fiberglass bats even though I specified cellulose I can't argue with the zone 6 $130 a month budget on the all electric home...
Using a 5ton geothermal ground loop on a four ton total compressor system that has dual
one and a half plus two and a half times and then a third stage of all four tons

in domestic 100% instant and loop pumps off in recovery
HW heating in air conditioning mode

Apr 20, 2013 2:57 PM ET

Could you repeat that?
by Dan Kolbert

In English this time?

Apr 20, 2013 7:50 PM ET

I think it's like a Beatles record:
by Gordon Taylor

the meaning reveals itself when it's read backwards.

Apr 20, 2013 9:09 PM ET

Edited Apr 21, 2013 6:04 AM ET.

Cutting a way through the thicket photo above.
by John Brooks

I find the title photograph amusing ...
Why doesn't the guy just walk around or through the wimpy little branches?

I know that I am often guilty of "overkill" thinking and design....
Maybe that's what attracted me to Passivhaus :-)

Apr 21, 2013 6:30 AM ET

Edited Apr 21, 2013 6:36 AM ET.

Response to John Brooks
by Martin Holladay

Extending the metaphor: sometimes, when one's progress is impeded by dense vocabulary and complicated technical concepts, it makes sense to slow down and study -- to understand one's surroundings thoroughly, until a way forward becomes clear.

For beginners, however, this approach can take a long time. So sometimes a machete is useful, because beginners don't always have the time necessary to understand where they are and find a path forward.

Apr 21, 2013 7:00 AM ET

Excellent Article and Advice
by John Brooks

Martin, the article and advice are excellent...
I only find the photograph amusing.

Apr 21, 2013 12:01 PM ET

Another very informative article
by Tom Peterson

Thank you for another very informative article Martin.

As a future high performance home owner I have learned much from all of the articles that I have read on the Green Building Advisor site and the Building Science Corporation site has been extremely helpful as well.

The only thing that confused me was the 'Adhered "manufactured stone" veneer over OSB wall sheathing" red flag. After more thought I came to the conclusion that "adhered" is the key word here in that adhering it directly to the wall was the problem. Based on what I have learned over at BSC, it should be fine if it is installed over a 3/8 inch drainage mat over a water resistive barrier.

Your attic comments kicked of another area of concern that I still need to learn about and that is attic access. I have to learn how to make sure that it is well sealed and insulated.

Sadly, I don't think there is anyway to make my house and lifestyle truly green. I want a small house but the wife wants a large one and her vote is larger than mine. Her horses basically defeat any attempt at a green lifestyle although there are a couple of benefits. The barn's roof will make an excellent spot for PV panels and the processed horse food will continue to allow me to grow a very lush vegetable garden.

Apr 21, 2013 12:13 PM ET

Edited Apr 21, 2013 12:15 PM ET.

Response to Tom Peterson
by Martin Holladay

The horses fit well into a green lifestyle -- especially if you get rid of your car.

A wall incorporating adhered manufactured stone over OSB contains so many pitfalls, it's hard to know where to start. First, there is the problem of taking concrete and using it to make small concrete pancakes that are supposed to look like stones from a distance. I mean, really.

Then there is the problem of OSB sheathing, which turns into oatmeal very quickly if it stays wet for a few months.

Then there is the problem that the OSB is very difficult to inspect once you have anything adhered to it. (At least with vinyl siding, you can unzip a few courses and take a look at the sheathing.)

Then there is the problem that very few installers know how to flash a wall, and the fact that most U.S. windows dribble water into the wall assembly from the lower two corners of the windows. Where is that water going?

So, if you swap the OSB for rigid foam -- and you include impeccable flashing -- and you include a drainage gap with openings at the bottom to release liquid water, and openings at the top to allow the escape of ventilation air -- and if you use real stones instead of concrete pancakes -- you might end up with a green wall assembly.

But really, Tom -- that's a lot of things that you have to make sure are done properly if you don't want the wall to fail.

Apr 21, 2013 2:23 PM ET

by Tom Peterson

Martin, thank you for the detailed response!

I must be delusional because I keep thinking that by now I should know a fair amount about building science based on all of the books and articles that I have read. Hopefully what I don't know doesn't do my house in. I'm confident that I will not find experienced tradesmen that have an appropriate understanding of building science nor of a house as a system building approach.

Based on your response, I will conclude that placing stone or brick on an OSB wall would not be conducive to a house with a long life either. A goal in the back of my mind is that I would like the owner in a century from now to reflect back at how well the house was built a century earlier.

Is it unreasonable to assume that the water risks would be negligible if the stone or brick work was at the north entry to the house which was covered by a (eight foot deep) porch? Our house will be built in western Wisconsin.

Apr 21, 2013 2:38 PM ET

Response to Tom Peterson
by Martin Holladay

You are right: If you protect stone veneer with an 8-foot-deep porch, you don't have to worry about water entry issues (assuming, of course, that the roofer who roofs the porch knows how to flash the top of the porch roof, where the porch roof meets the wall -- a type of flashing that can be tricky if the wall includes a rainscreen gap).

However, you are stuck with an aesthetic problem: I can't imagine that you want a house that includes one type of siding over most of the house -- perhaps fiber-cement, to mimic clapboard -- and then another type of siding at the entry door -- perhaps stone veneer, to mimic an old stone house.

If you want your house to look like a stone house, it makes sense (aesthetically) for the entire house to look like a stone house. Otherwise, it's just a jumble, with glued-on siding.

The worst example of glued-on siding I ever saw was a house with two dormers; the dormer cheeks had fake stone veneer. The builder didn't even realize that a stone house can't have stone dormers. I mean, really -- where are the support walls for these fake dormer cheeks?

Apr 22, 2013 3:03 PM ET

Great interview Questions!
by Matt Risinger

Martin, Fantastic advice without all the jargon that kills newbies. I love your Builder/Architect/Designer questions. Can you expand on that for a future post? I'll be sure to tell my prospects to read this before interviewing me! Best, Matt Risinger Austin, TX

Apr 22, 2013 3:12 PM ET

Response to Matt Risinger
by Martin Holladay

I'm glad that you liked my article.

Feel free to expand on my list of questions for builders and designers in one of your blogs if you like. Of course, it would be nice if you gave me some credit for starting the ball rolling... and maybe included a link.

Apr 23, 2013 11:50 AM ET

Have you ever
by gavin Healy

Great article Martin.
Another question worth asking the builder is have you ever tracked the energy consumption of a building you have built? Do you know how many therms, gallons, or watts it takes to heat and cool your homes, and have you ever confirmed it after you built. So many new homes tested have have excessive fan and pump energy regardless of where the distribution is located.
It's hard for builders or their HVAC installers to get better if they don't understand what they are up to. The same could be asked of the energy engineers/ designers, have you ever checked how much energy one of your designs consume? in my region I have never seen a mechanical engineer check their design for actual energy consumption and as a result their is a big gap between what homes need and what's being specified. If it's possible for a builder to learn what an ACH50 is than it should be possible for a mechanical contractor to learn what static pressure is. At a minimum they will need to understand that to install a good ventilation system.

Apr 23, 2013 12:23 PM ET

Response to Gavin Healy
by Martin Holladay

Great questions -- great suggestions. Thanks.

Apr 23, 2013 10:25 PM ET

English Solar GeoThermal Instant HotWater
by JP Jon Pierce

Martin ! Thank you again.
Having a couple of questions though:

how small is a "smaller home" and
how much is recommended spent on "engineer" of equipment selection?
and how much for the blower door testing?

Since GeoThermal is really any Earth-Heat below grade transferred, and the ground loop of closed-loop a GeoThermal project IS directly related to having to know how to engineer an understanding of Heat Loads and Cooling heat gains to the loop (sizing), what is saved in upfront testing and engineering by simply demanding a loop-performance contract?
Such a contract that is in writing for such as in 50-degree ground, 'minimum 34 degree loop fluid incoming to GT Unit inlet in an 'average' cold winter, at 3gpm/compressor-ton (~ 2.7 per rated AHRI box ton- "size" ) i.e) like I guarantee in writing in zones5 to 6 about 6500 to 6800 degree day areas.

Lowest first cost GeoTermal with all relative components of including a water tank and On-Demand HotWater instant heating with a forced air unit (also integrating reasonable small radiant heating from one same unit) all if applicable tax credits are applied for now are not as "very" expensive as one would compare to systems requiring two units to do what others can do super-efficiently with one GeoThermal Unit as a System. - I have several reasons to believe (installing since 1980).

Another question is since V-Star compressors of IQ/Variable drives are only offerred in wide application ranges, as 2.1/2 and 4.1/2 and 6+ Compressor-Tons: How "engineering" wide are the margins of application(s) as to the old considerations of single speed equipment divided in half ton incremental selection 1/2 to 5 compressor-tons, relative to balance points being 10 degrees at one home and 5 degrees at another with LOAD-MATCHING equipment?

Monitoring seems simpler since 2007 since systems can have 7 to 9 sensor readouts and logging of all sorts of things for varifying loop and runtimes and more, so what about the history being able to really track simple low cost pre-building design builds vs. ?
$1000-3000 in additiopnal fees to date that could go towards reviewing and purchasing what already works so well yielding 5500 sq ft homes HVAC HW families of 6 and 7 @ 13,000 kwh (HVACHW metered) to 3200 sq ft 2 story over uninsulated basements using only 8,000 kwh for all HW and Heat and Cooling without ERV's etc. (?) -I do not mind harsh correctively strict comments or Q's , but I am just considering a leaflet especially about what I have tracked since 1983 very closely, and metered, since there is such a large number of great installs to compare to.

Apr 24, 2013 9:15 AM ET

Edited Apr 24, 2013 9:16 AM ET.

Response to Jon Pierce
by Martin Holladay

You asked four questions. I'll do my best to answer them.

Q. "How small is a smaller home?"

A. In 2010, the average size of a new single-family home in the U.S. was 2,169 square feet. So any new home that is 2,000 square feet or smaller is smaller than average.

Q. "What is saved in upfront testing and engineering by simply demanding a loop-performance contract?"

A. I'm not sure how many ground-source heat pump contractors offer loop-performance contracts. It's possible that insisting on such a contract might increase the cost of the system. I can't imagine that insisting on such a contract would lower the cost of the system.

Q. "How engineering wide are the margins of application(s) as to the old considerations of single speed equipment divided in half ton incremental selection 1/2 to 5 compressor-tons, relative to balance points being 10 degrees at one home and 5 degrees at another with LOAD-MATCHING equipment?"

A. Please re-phrase the question in conventional English.

Q. "What about the history being able to really track simple low cost pre-building design builds vs. ?"

A. I don't know, Jon. What about it?

Apr 25, 2013 7:26 AM ET

200 miles from the Freudian Slip?
by Greg Labbe


It sounds like the Energy Nerd sees Canada's perm rate as low - like a poly - but we like to think our border is open enough to breathe!

A great article by the way.

Greg Labbe

Apr 25, 2013 8:40 AM ET

Response to Greg Labbe
by Martin Holladay

Thanks -- the slip has been fixed. (I type the word "barrier" 24 times a day, and sometimes my fingers type automatically, as soon as I press "b".)

Apr 25, 2013 4:06 PM ET

Edited Apr 25, 2013 4:19 PM ET.

Rephrased: Saving on performance guarrantees bests
by JP Jon Pierce

A. Please re-phrase the question in conventional English:
If one takes a lot of time and second and third visits desiging with (I have 'em) pet-balance points and loops only ending up at under Energy Star minimal 32f Entering GTHtP's
why not just size to a guaranteed 34f or more Ground Loop in contracts, to SAVE MONEY (causing less carbon, ultimately) after recovering in a year or three such an upsell, yielding greatest ROI's afterwards? (like better insulation , but stopping at diminishing returns)

Why not -when practical, avoid incremental selection as towards presumptions of one customer wanting "our" balance points with supplemental heat vs. a customer who frequently might want to leave supplemental heat off?
Since for three decades 3-Staging with Dual Compressors: , Can be mostly avoided with a Variable GT now available;
and in small homes
- it is the instant hot water of 30,000 btuh that may be more important with GT HVAC-Reclaim in cooling to the HW tank:100%, loop pumps/well pump off for that 20 minutes recovery.
(a little larger ground loop, much larger $ ROI'sin years to follow) .

Q. "What about the history being able to really track simple low cost pre-building design builds vs. ?"

A. I don't know, Jon. What about it?

Why not have that Q of yours in another post for others to list the many ways for over a decade practical tracking has been done? and especially with log file keeping and sensors OEM installed since 2007 residentially to cover those other bloges of comparrisons needed.

Almost every one of my installations have meters on the equipment since 1993.
We can see Earth-Heat of any transfer, is really just GEO-Thermal and I thiink if 76% or so is 100% sustainable-renewable as it is, why not compel the action of bests with more questions in posts about what ALL of the GeoThermal or now Airsource and Hot Water on demand can inclusive compare to? historically documented- and by so many in just this 'hot bed state' of mine as well.

Apr 21, 2017 2:01 PM ET

thanks for this
by Robert Swinburne

I was just poking around for a little light reading to send a few potential clients. This will do the trick quite nicely.

Apr 21, 2017 4:07 PM ET

Response to Robert Swinburne
by Martin Holladay

I'm glad that my 2013 article is still valuable.

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