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1 Answer

What is the best ventilation system for a passive design cafe/restaurant?

We are trying to design a passive cafe/restaurant building and i want to know the best ventilation system to use for the building please.

In PassivHaus | Asked By monita taghva | Oct 20 14
6 Answers

Reasonable retrofit efficiency goals

As I battle with an hvac solution for our home, we are leaning more and more towards trying to reduce the load further. I'll mention some details of my own house a bit below but I'm actually asking in hopes of a more generalized discussion of what a reasonable retrofit btu and ACH50 goal is.

I did some reading tonight in the hopes of answering this question but didn't find any useful rules of thumb. I know, the old HVAC rules of thumb have caused a lot of grief. I'm not asking for a rule of thumb about BTUs/sf for heat but rather what is rationally achievable in a retrofit scenario.

In Energy efficiency and durability | Asked By Keith H | Oct 19 14
5 Answers

Insulation design

Climate zone 2a.....south east Georgia coastal island. Bought a 1962 block one story house, The interior walls are painted block....we like the beach look associated with this concept. So, all insulation must be on the exterior of the house....which now us striped to bare block. Interested in the correct approach for water management and insulation. Exterior will eventually be cedar shingles.. Sort of thinking....spray closed cell between furring strips with ridged foam sheeting over the spray foam and strips. Then plywood covered with rain drainage screen topped with shingles.

In GBA Pro help | Asked By Robert Brown | Oct 17 14
5 Answers

IRC 316.4 - Code interpretation on the use of rigid foam as air barrier on backside of attic knee wall

My insulation plans for my attic kneewalls were to install two layers of 2" eps with staggered and taped seams, then install damp sprayed cellulose in the 2x4 stud cavity, followed by 1/2" drywall. I believe that a thermal barrier is required since I have usable attic space, but I am unclear whether this thermal barrier must be installed on both sides of the stud wall, or only the portion of the stud wall that faces the interior of the attic room. The gray area is whether or not the areas behind the stud wall are considered the "interior of the building".

In Building Code Questions | Asked By Rick Van Handel | Oct 17 14
3 Answers

Can we install an HRV in our house now?

Our house is one year old, we live in Vancouver, 5000 sfu on three levels. We have duct venting for our Lennox Furnace, Air Conditioner, and Air filter. I have to run 3 upstairs bathroom fans to avoid moisture forming on the windows. We have only recently learned that the contractor did not install a HRV.

Do I have to install new ducting (which I can only image is a huge job) or can the existing vents somehow be used?

Regards
Mark

In General questions | Asked By Mark Orsmond | Oct 18 14
2 Answers

Self-leveling compound

Hi there, I laid some engineered wood flooring on concrete with Mapei Ultraplan M20 self-leveling compound over a week ago. The bags said zero VOC premixed.

There was an awful sweet/fruity chemical smell when I mixed it. I called Mapei and they said it would go away when dry.

However, the smell is still here. I would have thought the underlayment (AirGuard Roberts 3-in-1) would cut the smell but it's bad.

I need to level plywood subfloors upstairs to finish this job and wondering if anyone can recommend an equivalent product that doesn't stink.

In General questions | Asked By Brooke Beloso | Aug 8 14
34 Answers

Options for high R-value above-grade walls (R-80)?

To make a long story short, my above grade exterior walls need to be at an R value of 80. This is to meet Passive House standards for a new residential house in a very demanding climate.

I am currently planning on using SIP's of some sort. But even the best of those only get me up to around R-50 though. Any thoughts on ways to get to R-80 while still being cost effective and keeping the size of the wall to a minimum?

I have found a number of options myself, but was curious if anyone else had thoughts or suggestions to meet such a high R value for a wall.

In Green building techniques | Asked By Tom Schmidt | Sep 19 14
4 Answers

Plastic or smart vapor barrier in zone 6?

My builder is planning on using a normal 6 mil vapor barrier on my new build ...the wall structure is R-22 fiberglass with 5 inches of EPS foam on the outside ....the building inspector says that is code ...

In General questions | Asked By bob holodinsky | Oct 18 14
2 Answers

Rated output for electric radiant ceilings?

I've been searching the web for a rule of thumb to calculate the rated output for a 40 year old electric radiant ceiling system. Must be some rule of thumb like 10 btu per suare foot......but I can't find it.
Thanks

In Mechanicals | Asked By Walter Gayeski | Oct 17 14
2 Answers

Catherdral ceiling insulation

We have a cape cod and are having a new roof installed. The stairs leading up to the second story, the cathedral part, with two rafter bays of 2x6's had no insulation in them. The roofers pulled the roofing deck and put in some batt insulation, (R30 with a plastic wrapping that had holes) and some attic cat they put in by hand. They also put in plastic baffles between the decking and the insulation. Unfortunately at the bottom of the rafters it is completely blocked off. So there will be no air being pulled in from the soffets. There isn't a way to get them open.

In General questions | Asked By HD S | Oct 16 14
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