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33 Answers

Best insulation for indoor air quality?

I cannot decide on a type of insulation for our new home. I want something that is the safest for indoor air quality. I am worried about the off gassing of spray foam, but am also worried about the borate used in blown in cellulose (mainly the reproductive effects of borate). Please help! I want energy efficiency, but indoor air quality is of primary concern. Thank you!

In Green products and materials | Asked By Carolyn Farrow | Feb 8 16
2 Answers

A couple of renovation questions regarding my 1960 Cape

Hello all, I was looking up information on housewrap, and stumbled upon this website, what a great find. Anyways, I’m hoping to get some information/advice as the best way to go about doing some renovations this spring/summer on my house

In General questions | Asked By Khouri Rice | Feb 9 16
2 Answers

How do I calculate the interior temperature of a window at a given outside temperature with a fixed interior temperature?

I am trying to predict at what outside temperature will I get condensation on my windows. If it is 70 degrees inside with 40% relative humidity and my window has a u-value of .3 at what outside temperature will the window (frame and center of glass) have condensation. How do I calculate this?

In GBA Pro help | Asked By Chaz Steffen | Feb 9 16
4 Answers

Homemade dog house insulated panels

I'm having to make a homemade dog house for my rather large Akbash mountain dog family (papa, mama and 12 wk old pup). I live in Region 5, western Colorado. I need a floor panel, roof panel, and 4 wall panels. I had this design for making the panels utilizing empty water bottles. What do you think? Will this work well enough to keep in heat and block outside cold air? I wish I had some idea of the R value. Cut 42" long x 36" tall 1/2" thick thick plywood panels. Glue 2x4s around inside edge of each wall panel perimeter, on the wide (4") side.

In Energy efficiency and durability | Asked By Andy Nels | Feb 7 16
5 Answers

Radon venting in 1/2" crushed rock?

I have about 9" of 1/2" crushed stone as a base for the slab (2" of foam will go between stone and slab). I searched for clean, no fines, and the best I was able to get is mediocre clean.

Will installing 4" perforated PVC pipe in this material still work as a radon vent?

Would the efficacy be improved if I backfilled the 8" deep x 8" wide trench for the pipe with 3/4" rock?

How long should the pipe be?

Thanks.

In GBA Pro help | Asked By David McNeely | Feb 9 16
7 Answers

Reducing noise transfer between rooms through ducts

In our current house which has all rigid metal ducts, noise transfers easily between rooms through the ductwork. For our new house, I want to make sure that the HRV ductwork does not have the same problem.

Flex is often maligned but it seems as though it could be useful in limited quantities. Based on what I read here, it seems that running a short section from the metal trunk to each room, while making sure the section is straight, pulled tight, and sized for the proper airflow (which probably makes this section upsized from the metal diameter), should not cause a problem.

In General questions | Asked By Nick Hall | Feb 2 16
1 Answer

Does a rainscreen assembly maintain the exterior surface of paint?

I am trying to argue for a rain screen assembly. Is there any evidence that would highlight extending the time between painting the exterior siding by using a rain screen?

In Energy efficiency and durability | Asked By Julie Klump | Feb 9 16
7 Answers

Using a second water heater as an indirect fired tank?

I have two water heaters. A 50 gallon HTP Phoenix Light Duty propane water heater, and a 50 gallon electric resistance water heater. The two heaters are plumbed in series, electric water heater first, then propane. To make a long story short, some things didn't work out as originally planned, and now I'm paying an extra $15-20/month (and wasting source energy) because I'm heating up a bunch of water with electric resistance right next to a high efficiency propane water heater.

I'd like to stop doing that. I have a couple of extra constraints:

In Mechanicals | Asked By Tim C | Feb 8 16
4 Answers

Alternatives to SPF to insulate floor

I have a late 50's ranch house with a vented crawlspace in the San Francisco bay area. There are remnants of old cellulose insulation in the vented attic, though very little remains. The rest of the house is pretty much uninsulated. Even though we are in N. California, the weather gets chilly, and predictably my hardwood floors (and stone/tile floors in the kitchen and baths) have been very cold this winter. I am in the process of finding a good contractor to do a whole home energy audit, and come up with solutions (as green as possible) to make the house more comfortable (i.e.

In General questions | Asked By Zach H | Feb 3 16
7 Answers

Air exchange / ventilation / dehumidifier options for a sealed, 640 s.f. structure

I am building a 640 s.f. structure and insulating i twith closed cell spray foam. Heat is provided by a fireplace with an outside air supply and baseboard heat.

I need an energy-efficient air conditioning / ventilation / dehmidifier / air exchange solution, mainly to keep it dry, but also to keep it cool.

It is located in a typical, four season climate where we get hot, humid summers and cold, snowy winters.

In Mechanicals | Asked By Nathan Hiscock | Feb 8 16
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