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3 Answers

Does a heat pump always make sense?

We thought to replace a 10 SEER AC unit and a 45-year-old oil furnace with a heat pump. When we look at the potential savings to purchase a 3T unit, it doesn't add up. In our 2400 sq ft home, we use 450 gallons of oil/year and $400 (worst case) of electricity for the AC. We would need to add a 20kW heater to the heat pump in order to replace the furnace.

Should we just wait until the furnace or AC break?

In Mechanicals | Asked By Mike Stelts | Jun 4 12
2 Answers

Laars tankles water heater

I was at my in-laws summer house over the weekend and went into the mechanical room. I was surprised by how warm the room was. They have a Laars Mascot tankless condensing boiler for hot water and radiant heat.

There was no water being used and the radiant system was not calling for heat.

Since this is an on demand system, I figured it would not give off much, if any, heat since the house had been vacant for at least a week.

In Mechanicals | Asked By Kevin Karlberg | Jun 5 12
3 Answers

Sun porch for solar gain?

I'm retro fitting a small ranch with 12" cellulose walls, 20" cellulose cold attic, warm crawl space. It has a long screen porch along the south west wall. I am considering enclosing it with folding patio doors so it can generate solar gain during the cold seasons and still open up during the summer. I am in South Jersey.

In addition, I am planning to add mini-splits to heat and cool the space. It currently is electric baseboard ( no gas in the area). The finished house will be 2 stories and about 2200 sq ft.

In Green building techniques | Asked By Michael Arnold | Jun 4 12
2 Answers

Air tightness & testing?

The common method of expressing test results of air tightness tests is air changes per hour. @ 50 pascals. How is the building volume calculated? Does it include exterior wall volume (use outside dimensions)? Does it include an unheated basement? or crawlspace? In testing are vents for ventilation systems (HRV.ERV) capped? Are dryer or range vents capped? What is "state of the art" air tightness? What are best known test results?

In PassivHaus | Asked By Jerry Liebler | Jun 4 12
4 Answers

HELP! apprehensive about adding exterior XPS insulation

Hello everyone, this is my first post as an avid DIY homeowner. I have renovated multiple homes and I am a big fan of adding 2" XPS insulation board to the exterior as part of a window and siding upgrade.

This "NEW" house just sent me a curve ball. I just discovered that my "NEW" 1982 home in upstate New York (zone 6) has 1/2" foil faced polyiso between the studs and exterior sheathing.

In Energy efficiency and durability | Asked By Brandt Minkler | Jun 3 12
5 Answers

Exterior EPS foam fasteners?

Does anyone have a recommendation for fasteners for exterior foam application? I am applying 6-7" of exterior EPS foam in two layers (2x3", overlapping joints). Ideally I am looking for pneumatic nails with washers so that the fastener does not penetrate the foam.


In Green products and materials | Asked By Erik Lobeck | Jun 4 12
2 Answers

Storage shed outside — building for dual purpose

We have a shed -- storage for summer stuff -- which has doubled as guest sleeping in summer for visiting adult children. Please Read on and if you have suggestions, please let me know, as we are about to build a second shed -- the roof is a single slope, no ridge but vented on each end. I must be missing something, so any ideas? thanks.

This is how we built and use the first shed:

In General questions | Asked By oldhouse Inn | Jun 3 12
8 Answers

Mason Greenstar Blox?

For the last year or so, I've been planning construction of an ICF home in the Lubbock Texas area. I got sidetracked for awhile but I am getting geared up again to finish the design. I've not entirely settled on ICFs and recently came across another option - Greenstar Blox (lightweight adobe blocks made from "recycled short-fiber cellulose, portland cement, water, and an organic curing agent ad-mixture").

They are located in Mason Texas and here's the link to their website: http://www.masongreenstar.com/

Does anyone have any experience with this block?

In Green products and materials | Asked By D C | Jul 9 11
1 Answer

Input on Triangle Tube boiler products

Does anyone have any experiences, positive or negative, regarding Triangle Tube boilers?


In Green products and materials | Asked By Erik Lobeck | Jun 1 12
15 Answers

Working a wood stove into my hot water system

Hi all,

I'm looking for thoughts on how to tie a wood stove into my DHW system in a new house I'm building. Some background is needed though...

In Mechanicals | Asked By Jay Hersh | Aug 9 11
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