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10 Answers

Rigid polyiso in side attics?

As a spray foam alternative, I'm considering using continuous rigid foam along the 32ft long x 7ft slope in my side attic and just spray foaming in the lower joist bays and places where taping is difficult. The attics are about as simple as can be with no dormers or other obstructions. I will need 8" of polyiso to meet my disired R-value (R-48), while keeping the 2x4 rafter bays wide open for ventilation. There are also HVAC ducts and plumbing in the attic, which is why I'd like to convert it conditioned space.

Asked By Ryan Griffin | Nov 22 14
0 Answers

What U and SHGC is needed in temperate weather conditions to achieve NetZero?

In this wonderful community, Energy Efficiency is often been in reference cold climates. I live in California and am in the architectural stages of building a NetZero house.

We have two seasons: Summer and Rainy. The rainy season lasts from November to end of Feb and during those months it can actually freeze - although I doubt if we ever have more than 5-6 freeze days a year. In the summer we never have more than 5-6 days above 90 in a year. We probably have at least 330 days of sunshine.

Asked By Katherine Bretz | Nov 24 14
5 Answers

Could you please provide me of an example of a temporary one-floor sustainable building?

I am currently undergoing a project at college and i need to research temporary sustainable buildings

Asked By Alfie Andrews | Nov 24 14
8 Answers

1.5" of rigid insulation over stucco; Polyiso or EPS?

I have a stucco house in high desert New Mexico (zone 5B). The stucco is in bad shape after having been terribly abused by the previous owners, so I'm taking the opportunity to have the whole house wrapped in continuous rigid insulation as part of the re-stucco project. The boards would be applied over the existing deteriorating stucco, fastened through it and the sheathing and to the studs, and then a new 1/2" two-coat cementitious stucco cladding will be attached over it.

Asked By Nathaniel G | Oct 2 14
0 Answers

moisture in sleeper bays over T&G roof decking?

8 years ago. The existing clerestory low slope roof had 2x sleepers over T& decking with insulation between with sheathing and a membrane roof over. the new addition duplicated this and the entire roof was re-roofed with a new membrane. the 2X T&G decking is exposed to the living space below and is dry...no leaks. the owner is complaining of a "Soft" roof and suspects that interior moisture is trapped in the 2X sleeper bays and rotting. any thoughts? EPD

Asked By ed spencer | Nov 24 14
7 Answers

Designing a passive solar / net zero house in NC Mountains

My wife and I are designing a new mountain home in Banner Elk, NC. We are in the initial design stages with our architect and are confused by the numerous options to consider. Our house will be built in the Eagles Nest community which has a pacific northwest lodge feel. Our home site is at a 5,000 foot elevation on the mountain ridge with a northern view.

Asked By bill Moseley | Nov 23 14
3 Answers

Heat-pump water heater in conditioned space

I am building a net-zero energy home to Passive House standards in the Seattle area. The best scenario for a heat pump water heater is in an attached garage, unheated basement or in the conditioned space of a house in a humid heating climate (why doesn't everyone in Florida own one?). Unfortunately, my only option is within my conditioned space in a heating climate. My heating system will be a ductless minisplit air source heat pump. I would prefer to not remove the heat from my utility room only to make my heating system work harder.

Asked By Gerald Blycker | Nov 24 14
2 Answers

Stranded Bamboo Flooring, Is it a good choice?

We are building a home in Alabama on the coast. We have a crawlspace sealed foundation that is dehumified. We are looking at purchasing 5/8 - 1/2 Stranded, Carbonized, bamboo flooring. We are getting mixed reviews on whether this is a good choice. We've heard the following:

Pro - it's solid engineered so it can be sanded and refinished. The color is the same all the way through. Compared to engeered wood which can only be sanded and refinished once.

Pro - Harder than most woods, and compares to engineered wood in that it's harder to scratch.

Asked By Mary Smart | Nov 20 14
0 Answers

What is the efficiency of gas powered infrared radiant heat?

My project: Climate zone 6A Hortonville, WI 54944 Energy source: electric or propane, no natural gas available

An earlier post about heating garage brought up the possibility of gas powered infrared radiant. I'm familiar with these devices, but I literally can't find any information from the manufacturers regarding their efficiency. They all claim to be "very efficient" for various reasons, but I can't find hard data.

Are they rated by a percent like house furnaces? I.E. Are they in the range of 80% efficient ceiling hung unit heaters?

Asked By Rick Van Handel | Nov 24 14
6 Answers

Spray foam insulation

I have a 100 year old house in Zone 5. There is a sunroom (approx. 5'X20') on the south side of the house which is all windows. It is built on piles (about 4' to the bottom of the joists) and open underneath with lattice. The room is open to the living room of my home and is heated by 2 forced hot water radiators. When we bought the home the floor was insulated from underneath by batt insulation and rigid insulation between the joist cavities. We had an energy audit performed when we moved in and were told this was all good. Still, the floor has always been cold.

Asked By Danny Mac | Nov 17 14
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