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2 Answers

Are tubular skylights / Solatubes thermal chimneys in a house?

My house design has a long E-W axis in order to exploit Southern exposure and this creates a middle of the house, mostly hallways/foyer, which have no window exposure.

A solotube piping some natural lights into these dark areas would be terrific, but what I don't want to create is an attic with r-80 coverage and have most of the heat in the conditioned space bee-lining for the "weak spot" under the solatubes and then race up these chimneys.

Are there any energy efficiency tricks in the grab bag of methods used by Green builders to bring light into dark areas of the house?

In Energy efficiency and durability | Asked By Alex House | Feb 11 15
4 Answers

Polystyrene over vapor barrier?

I'm in the process of finishing the inside of my new pole building....
Currently, between the 8' on center columns there is batt insulation installed with a vapor barrier to the inside of the space, then metal panel from the floor up 4', open space up the next 8' (that will be covered with 3/4" MDO) with horizontal nailers spaced 16" apart, then the next 4' up to the ceiling is covered with metal panel.

I'm thinking about adding 1-1/2" pink foam board between the nailers on the outside of the vapor barrier.

In Energy efficiency and durability | Asked By Dennis Filer | Feb 11 15
6 Answers

How would you compare Greg La Vardera's New USA Wall assembly with a SIP wall supplemented with Comfortboard mineral wool?

Planning to build a new "Pretty Good Home" in coastal Massachusetts (Zone 5A) in the spring, and am wondering about performance, durability, cost, and ease of construction with the two envelope systems in the question; architect Greg La Vardera's "New USA Wall" framed with (advanced framing) 2x6s, versus a 6" EPS SIP with an exterior layer of 2" Comfortboard rigid mineral wool (R-8) and an interior 1 1'2" utility race insulated with 1 `1/2" Comfortboard (R-6)? Both assemblies have similar overall R-value, but which might be more cost-effective, durable, and easier to build?

In Green building techniques | Asked By JAMES KREYLING | Feb 6 15
4 Answers

Designing a Passive House

Hi all, my company has been chosen to design and build a certified Passive House in the Rocky Mountains of British Columbia. We have pretty much been given carte blanche for the design so long as it hits our target as cost-efficiently as possible. With that in mind, I thought I would see if any of you had any thoughts or ideas on how best to proceed. It could be floorplan suggestions, window options, appliances, wall stack up...anything really.

In Green building techniques | Asked By erik olofsson | Feb 11 15
3 Answers

HVAC prior to spray foam?

I was under the assumption that one would FIRST spray foam the underside of the roof and then install the HVAC duct work, not the other way around. Ran into a scenario where they will install the HVAC duct work first and then spray foam the underside of the roof.

Even though the duct work will sit below the roof deck area. It will get in the way when the spray foam the roof area. At least that was my assumption.

Has anyone seen it done that way? Duct work first and then spray foaming?

In Green building techniques | Asked By Peter L | Feb 11 15
3 Answers

Sheathing between foil-faced polyiso and closed-cell spray polyurethane foam

I'm working on the details of an R-40 Wall in Southern Indiana, Northern Climate Zone 4. Please see the attached file.

Among many options is to use 2" of properly layered, sealed and taped FFPIC [foil-faced polyisocyanurate] exterior to the sheathing and an Advanced Framed stud cavity filled with CCSPF [closed-cell spray polyurethane foam] on the interior. The house will have 3' Overhangs, Brick Cladding, and a 1" Rain Screen.

In Energy efficiency and durability | Asked By Ted Cummings | Feb 9 15
2 Answers

Is spraying 1 1/2" of closed-cell foam to the interior of block walls an efficient form of insulation?

I have a structure located in central AR that is 8' tall block walls. The wall cavities are NOT grouted. The walls are above ground level. The interior of the walls are lathed with 1 1/2" thick strips. Im looking to spray 1 1/2" of closed cell foam directly to the blocks. Will this be an efficient form of insulation?

In Energy efficiency and durability | Asked By Zach Lacy | Feb 9 15
3 Answers

Are leaks in a structure...

Checking for leaks? is the Green's leakage decreased in homes, now that it has gone green? Or, is it basically the same / near or = to studies (in normal construction techniques)?

In Plans Review | Asked By arf shr | Feb 8 15
1 Answer

Is there any manufactured "thermal-bridge-free" door hardware on the market?

As we seek to reduce and eliminate thermal bridges in our buildings, things like door hardware show up as thermal bridge challenges. Usually, door hardware consists of assemblies of thermally conductive metal that "bridge" the door, conducting heat from the interior through the door (insulated or uninsulated) to the exterior. Thermally conductive hardware may seem insignificant in a leaky building, but it can become more significant as the building is made tighter and more thermally efficient.

In Green products and materials | Asked By Albert Russell | Feb 10 15
8 Answers

Air Exchanges in a new house

We are building our retirement home in zone 3 at the coast in North Carolina. I've come to know more about some of the design considerations for HVAC thanks to this site and I'm looking for some reassurance given that all our savings are going into this project.

In GBA Pro help | Asked By John Pugh | Feb 6 15
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