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1 Answer

Detailing a Chimney

I know, I know---if I really wanted to be efficient, I would eliminate the chimney. However, I love a good fire and the warmth from it. So, my new house will have a zero-clearance wood-burning unit(RSF 320). The chase for the chimney is mostly inside the envelope, except for a portion at the top. I have attached the rendering to show what it looks like from outside. I am wondering how exactly to air seal and insulate this in an ideal manner. I have attached another simple diagram trying to delineate the air seal. This house will have a spray-foamed, unvented attic space.

Asked By Kevin Spellman | Nov 21 17
8 Answers

Which gas furnaces are most efficient in their use of electricity?

I am about to replace a 13 year old 120,000BTU furnace with a much smaller unit that will be less noisy.

I understand that the fans of these units are a significant power draw. The state of MA will give the same rebate to all 95%AFUE furnaces. Is there a difference, where some brands of 95% AFUE furnace will actually use a lot less power?

FYI my furnace is in the attic so I will end up putting in a horizontal downflow unit.

Asked By rich cowen | Nov 16 17
7 Answers

Attic fan for ventilation in winter?

I have ice buildup because of heat escaping and melting snow and causing ice buildup on my gutters. I have vented gables on both ends of my attic in a split foyer home. Can I install of ventilation fan and set the temperature at say 40 degrees to move that warmer air out and avoid the ice buildup??
Any advice is greatly appreciated... Mike F

Asked By Feiks | Nov 20 17
8 Answers

Best way to insulate attic

My attic currently has R19 foil faced fiberglass batts installed. I would like to air seal the entire attic and re-insulate with blown in cellulose.
The original plan was to cut EPS to fit between the stud bays and seal with great stuff, followed by the fiberglass and blown cellulose. From my understanding, EPS or any rigid foam is not worth the labor for this particular application.

Should I remove the fiberglass batts, caulk/foam the seams and openings, and then reuse the fiberglass followed by cellulose?

Asked By craziekeiichi | Nov 13 17
13 Answers

Condensation on windows

I am a HERS rater, back in the summer, i tested a house for a builder.
built about a year ago and lived in.
​they​ had a problem with condensation ​collecting​ on windows
windows face north, and air changes in house were 2.4ACH
they had one continuous fan that was not working
so they replaced this fan which is guest bath, off kitchen, near laundry.
this now is supposed to run at 60 cfm continuous.
They replaced a second fan in the master bath to run continuous at 50,
occupied at 100cfm. ​both on the main floor, there is no second floor,
but a finished walk out basement.

Asked By Dwayne Petko | Nov 17 17
11 Answers

Does Anyone NOT recommend using Zip R3 in CZ 4 (Northern Virginia)?

We are working with an architect to design a practical and cost-effective 'energy-smart' located Fairfax County, VA (outside Washington, DC). I am not an architect, engineer, or building scientist, so trying to decide on a practical, energy efficient, above-code (tight envelope and higher assembly R values, but not NZER or Passive), durable, cost-effective wall assembly has proven harder than expected.

Asked By user-6777975 | Nov 13 17
7 Answers

Insulate a cabin to last

Martin - I've learned a tremendous from you & GBA. This is a 1st asking a question. I'm also an engineer & lic Home Inspector, and I see what happens to homes.
I'm current building a cabin in northern Hayward, WI (Zone 7). I'm on a slab, 20'x26', 1 1/2 story, 2x6 walls 16" OC. I had a local carpenter put up the shell, and the rest is up to me. The cabin is sheathed in OSB, Tyvek, Fascia/soffit, and Anderson windows & door are in. I installed kraft faced R19 Batts in the walls (drywall & siding are not yet installed).

Asked By Dan Musielski | Nov 16 17
8 Answers

Roof membrane and live vegetative roof

Hey all,

So after Material quotes and city grants etc, it looks like its going to be viable go me to do a live vegatative roof (green roof) on the flat roof I've recently built.

now I'm thinking about what roofing membrane to put on, to go under the green roof. I am considering things like cost, longevity, ease of install, potential for leaks etc.

I'm in climate zone 6. My potential roof assembly is as follows:

9.5" I joists with R31 rockwool batting
3/4 plywood decking
6" polyiso at R34
1/2" roofboard
Roofing membrane ***
3" green roof assembly

Asked By Jamie B | Nov 18 17
12 Answers

Remodel - Insulating a permanent wood foundation (PWF)

We recently purchased a log home built on top of a Permanent Wood Foundation (PWF). It's a ranch style (26'x47') single story. Built in 1980. We have completely gutted the basement. We are down to the 2x6 stud walls 1-foot on center of the PWF. Previously the house was heated via a wood burning furnace and electric baseboard heat, which have both been removed. We had geo-thermal installed utilizing the duct-work that was in place for the wood burning furnace. It's a ground source heat pump made by Water Furnace (5 Series).

Asked By Jeepasaurus | Oct 30 17
7 Answers

Flat roof attic insulation

My home was built in the late 1890s and has a flat roof. It has aluminium siding and it has two floors and basement. On the second floor, we have sheetrock ceiling. There is an older plaster and lath ceiling on top of the sheetrock. There is about a foot of space between the ceiling sheetrock and plaster ceiling. In the attic, there’s no insulation at all. On the edges, you can see the stud cavities that run down to the second floor. You can only see down to the second floor and not the first floor. So not sure if it is called balloon framing.

Asked By michaeldrehl | Nov 17 17
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