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26 Answers

Basement is too cold, need help in insulation

I live on the border or CT and MA. My basement is around 47 degrees. I have my basement roof insulated with R30 batt insulation. When I measured the temperature of my basement walls, above grade part is coming around 35-40 degrees and below grade is about 40-45 degrees, my basement floor is around 45-50 degrees. I put durashield paint on the basement walls to prevent from moisture ( I did not have too much moisture but I still wanted to avoid any future issues), similarly I painted my floor with two part epoxy.

In Energy efficiency and durability | Asked By Amit Jindal | Feb 16 15
2 Answers

Multizone minisplit air conditioning?

Can someone tell me why I can't buy a multi-zone mini-split AC only system? Trying to find a good solution for AC for a 6-room boutique hotel in Belize. No reason to have (or pay for) heat.

Also, multi-zone systems are completely independent of each other accept for the exterior unit, correct? In other words, room A could have 2 wall units set at 72F while room B could have 2 units turned off or set at 68F, correct?

(I'm listing this under mechanicals because there wasn't a "no question is a dumb question" section!)
thx - Mike

In Mechanicals | Asked By Mike carey | Mar 9 15
10 Answers

Trombe wall (non-vented) with exterior moveable mode of insulation?

I am in the process of completing my energy efficient house design. Approximately 80% of the Building Envelope will be a Double Stud Wall Construction allowing for roughly 11" of Cellulose Insulation in addition to a 1" Rigid Insulation outboard of the Sheathing and inboard of the Hardie Cement Fiberboard Skin. The Remaining 20% of the Envelope will be Double Glazed Fiberglas Windows with emphasis placed on the South Elevation (Perhaps 60% on South, and 20% each on East and West). However, on the South Elevation I also have two sections of Trombe Wall - each 8' in width and 12' in height.

In GBA Pro help | Asked By Thomas Tricarico | Mar 1 15
4 Answers

Paradigm Windows

Who's used them and what do you think of them? None of the references I found here were from people actually using them, curious what the drawbacks are. Aside from vinyl isn't for everyone.

In Green products and materials | Asked By Aaron Vander Meulen | Mar 6 15
7 Answers

How would you insulate a metal Quonset hut?

I have a client interested in building a home inside a metal Quonset hut. I am concerned about how to insulate the building. Applying a closed-cell foam directly to the interior of the structure seems like a plausible option that would be like creating an invented roof assembly. However, I am concerned about the following: (1) might there be a negative chemical interaction between the foam and metal that could cause corrosion? (2) Are there moisture risks that could lead to problems?

In Green building techniques | Asked By Andy McDonald | Mar 6 15
10 Answers

Was ventilation required?

I have a commerical 15500 sqft per floor total 3 floors totaling around 46500 sqft building under construction that have low slopped flat roof that is almost flat with just a little slop the architect designed this roof with a TPO from firestone company that his TPO roof on first layer under TPO roof

In GBA Pro help | Asked By Deven Patel | Mar 7 15
3 Answers

Why not? Minisplit inline with ERV ducting

I am building a somewhat wide (70+ ft x 32ft) house and am thinking of running a minisplit inline with a erv. I saw it done by hammer and hand in their videos on the pumpkin ridge project. Has anyone else ever done this or know how or why not to do it?


In Mechanicals | Asked By Andrew Bennett | Mar 7 15
4 Answers

PERSIST - Vapor-open or vapor-closed insulation and WRB?

So I just got back from Building Energy 15' - what a great conference! I had a few conversations about various vapor barriers, insulation and how each works with the PERSIST technique. I wanted your feedback though......

In General questions | Asked By brad hardie | Mar 6 15
6 Answers

Spray foam optimal or does another solution exist?

In Energy efficiency and durability | Asked By Todd Munson | Mar 6 15
2 Answers

Membrain in walls, poly in attic. OK or not?

I join hundreds of others in trying to wrap my head around the nuances of vapor retarders.

In this thread in comment #32 Martin notes that ceiling poly is unlikely to cause much trouble and then in comment #34 he observes that another person should use Membrain in their walls.

Is there ever a need for Membrain in the ceiling or can cheaper poly always be used?

One other question.

Poly in walls should be on the warm side, Martin quoted the following from the same article:

In Energy efficiency and durability | Asked By Alex House | Mar 6 15
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