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41 Answers

Best way to have a wood fireplace?

We are building a custom house, and are nearing our final planning stages before bids with our architect. We are planning to have a wood fireplace on the ground floor, within the building envelope. When it is burning, it will likely to burned with any glass doors on the fireplace open, for aesthetic reasons. It is only going to be used as a heat source as an occasional backup. What are the best ways to minimize the energy problems of an wood fireplace? It'll probably be a zero-clearance type of fireplace. My husband will not agree to a gas or wood stove, so don't even suggest it!

In Energy efficiency and durability | Asked By Clara Kim | Feb 22 15
4 Answers

Why is it so trendy to hate on radiant in-floor heat?

I recently built a 2000 square foot house in climate zone 7. The building is two stories on a slab heated by a Navien 240a combination boiler. There is no heat source on the second story, and the simple system has only one zone, which is all it needs because all the rooms in the house stay at the same temperature--maybe it's a few degrees cooler in the upstairs bedrooms if the doors are shut for 24 hours or more. I spent just over five grand on the heating system--installed--although I got a tankless water heater in the process, so the real cost was more like $3500. How is that overkill?

In Mechanicals | Asked By Josh Jipson | Mar 1 15
13 Answers

Insulating a low-slope EPDM roof from the ceiling below

Hi. I recently had an Epdm roof installed on my 140 year old house. It's low slope and meets with a gable roof on the other part of the house. The Gable is standing seam. We had a tapered ISO board system installed as the underlayment to help with drainage and make the edge details easier to deal with. I reframed the roof and sheathed it myself before the roofing contractors started so I could save money. At the time the ceilings underneath the roof were all closed so I installed 4 inch rockwool batts right on top of the plaster/lath of the ceilings below.

In General questions | Asked By joseph moore | Feb 26 15
4 Answers

Adding wall R-value in a historic retrofit

What options are available for adding r-value to a wall if we can't remove the exterior siding? I see three options...
1) dense pack cellulose in the existing 4" wall cavities (~R 14-16)
2) Closed cell spray foam in existing 4" cavity (~R 26-28)
3) Add a double interior wall filled with 7.5" of dense pack cellulose (~R 26-28)

In Green building techniques | Asked By alok khuntia | Feb 28 15
9 Answers

Foil-faced batt insulation effect on wall construction?

I’m in the process of planning energy retrofit for my house located in Philadelphia (zone 4A)
Existing wall construction consists of t1-11 over 2x4 framing with foil-faced batt insulation. The plan is to add 2 layers of 2” polyiso to the exterior taping joints making polyiso my WRB. Is there any concern that moisture trapped in the wall cavity won’t be able to dry to the interior due to foil faced batt insulation?

thanks!

In GBA Pro help | Asked By Michael Kalustov | Feb 27 15
4 Answers

What is a correct way of fastening two layers of 2" rigid insulation to the exterior of a 2x6 wall?

I would like to know the correct way to fasten two layers of rigid foam insulation where the total thickness is 4". I am concerned that when hanging this thickness of foam it will be difficult to be sure that the siding application is secure. We will be using HardiePlank horizontal lap siding. This is a form of cement board and heavy on it's own. Any advice.
Thanks

In Green building techniques | Asked By william dempsey | Feb 26 15
5 Answers

Dense packing cellulose - height of cavity

What are the thoughts out there on how tall a cavity in this double stud wall can be before there are concerns?

Here's the wall:

There's an outer 2x6 wall, 16" O.C., and an inner 2x4 wall also 16" o.c. There's a 6" space between the inner and outer studs, for a cavity depth of 15".

The first floor walls are 9' tall, with an 18" deep floor truss above. In other words, there will be a 10.5' height of cellulose. The second floor is about 8'4".

In General questions | Asked By Graham Fisher | Feb 28 15
4 Answers

Sturbridge, Massachusetts — electric boiler

Sturbridge, MA. Have abundant PV, similar to Ed Jones' question. Need electric boiler recommendations. 40 panel ground mount lease. Put in at the height of recent depression. VG deal.

Property has small slab, under 900' sqft,, 3'' foam under and sides. low e glass, 2x6 walls.

Have abundant solar PV, no electric bill, even this winter. I do clean the panels after storms.

Current fuel is wood, we do not need to discuss.

I would rather use up more solar electricity, instead of sell it back to the grid.

In GBA Pro help | Asked By howard kelley | Feb 28 15
4 Answers

Multi split with ceiling fans?

I am looking into a multisplit heat pump system for our deep energy retrofit project. We are used to leaky homes with ceiling fans in all bedrooms while sleeping. We find the moving air to be very comfortable while sleeping. In fact we noticeably miss the fans when traveling even when there is a dedicated Hvac like in a hotel room. In general, is the modern usage of the term 'comfort' (meaning stable temperature and humidity) consistent with our desire to feel the lightly moving air when sleeping?

In Mechanicals | Asked By alok khuntia | Feb 27 15
16 Answers

Recommendation for minisplits vs. gas-fired HVAC for new Massachusetts building

I am building an energy efficient 15 unit apartment building in MA this spring. We can either go natural gas or electric. I am considering going all electric since the MA Energy Code is so stringent and the heat load will be relatively small even though there are very cold temps at times. We might even put on solar panels for the house meter.
The electric units would take up much less space and I would rather not have to put in gas at all. I am not thrilled about electric hot water heaters but understand that the newer tankless units are much better.
Any input would be appreciated.

In Mechanicals | Asked By Bill Perkins | Feb 25 15
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