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6 Answers

Cavity insulation with exterior rigid foam

I'm looking for advice on stud cavity insulation. Walls will be (from outside in) LP smartside lap siding, 3/4" rainscreen gap, 6" EPS foam (R-24), self-adhering vapor/water/air barrier, OSB, stud cavity, then interior wall covering which will be either T&G pine or drywall with latex paint. My main floor walls are 2x4 and the basement walls are 4' below grade ICF and 4' above grade 2x6. I live in zone 7a - eastern North Dakota.

In Energy efficiency and durability | Asked By Adam Emter | Sep 5 15
2 Answers

Is closed cell foam insulation worth the cost for a 75 year old home with 2x4 exterior walls?

I am remodeling my 75 year old home. I am gutting the interior walls and adding a full dormer. The exterior walls are 2x4. Is it worth the cost for closed cell foam insulation or is a traditional fiberglass insulation sufficient? Thanks, Paul

In Energy efficiency and durability | Asked By Paul Hanson | Sep 6 15
9 Answers

Improving hot water heat pump tank efficiency with free dryer heat

Hi. I have been thinking about how to improve my GE electric hot water heat pump efficiency, particularly in the winter months. It is located in a very well insulated utility room off the garage (larger than recommended minimum volumes). The by-product of using the heat pump is cool, dry air, which in turn creates a cold room calling for accessory heat to warm the room back up to temp for the heat pump to then work efficiently again. I find the room temp is fluctuating up and down in conjunction with the use of heat pump this not making it as efficient as it could be.

In Energy efficiency and durability | Asked By Matthew Michaud | Sep 7 15
4 Answers

Does anyone have updated (current product information) on water heaters with heat pumps?

I am looking for a DHW heater (with heat pump) which will service both DHW and a radiant floor system? The project in question has approximately 1300 sf radiant floor system and having one appliance to service both efficiently would be very beneficial.

I’ve looked at the Sanden Eco (good information here in this forum) but it’s too late for the current project to design an exterior heat pump into the residence exterior; but I will certainly consider this next for future cleints since they will be available (I'm told) at the end of this year.

In Green products and materials | Asked By Caroline Di Diego | Sep 7 15
10 Answers

Thoughts on gas lanterns in green homes?

I am considering installing gas porch lights (wall mounted) when we do a deep energy retrofit of our 1888 victorian home. I think the look is great and cost is reasonable but I am debating the contradiction it would present by using such an inefficient lighting method on a high performance home. Do you guys have any opinions? thanks in advance.

In Green building techniques | Asked By alok khuntia | Sep 6 15
4 Answers

Vented attic vs. a sealed, non-vented, airtight attic

I'm building a new home in Miami, Fla.

An insulation contractor advises me to eliminate the planned roof & soffit vents and seal the attic with foam.
What are the Pros and Cons for maintaining attiic ventilation, and eliminating it?

In Energy efficiency and durability | Asked By Calvin Smith | Sep 1 15
8 Answers

Any hydronic system controls with low standby electricity consumption?

I was feeling good about the changes I'm making to reduce the electricity consumption of my hydronic system: a Grundfos Alpha ECM pump that is consuming only 16 W when it's running, and Taco "sentry" zone valves that use about a watt when on. But I measured the power consumption of controls last night, and it can add up to almost as much as the pump: 3 W for an aquastat, 6 W for a Taco "switching relay" circulator control with one zone on, and 4 W of standby power for the 40 VA 120:24 VAC transformer that powers the zone valves.

In Mechanicals | Asked By Charlie Sullivan | Sep 2 15
1 Answer

Has the Roxul sub slab technical bulletin been axed?

Back in May, there was a posting that Roxul will be publishing a technical bulletin about sub slab rockwool insulation. So far, I haven't seen anything from Roxul. Is anyone aware if the bulletin is still in the works?


In Green products and materials | Asked By John Ranson | Sep 6 15
2 Answers

Mini-split condenser on south side of house?

I'm in climate zone 2B. Winter nights drop into the 20s; days reach the 50s. Summer days reach 100 and cool to 70 at night. We get maybe a few inches of snow per year. The Manual J heating load for my house comes out to around 12,000 BTU, cooling around 6000. Would it optimize efficiency to place the outdoor unit on the south side of the house and shade it (with plenty of clearance) in the summer and expose it in the winter? (The south side is the best spot for other considerations particular to my floor plan.)

In Mechanicals | Asked By Jeff Cooper | Sep 5 15
10 Answers

Anodized aluminum vs. some other metal roof option

We have a summer cabin in Maine with a 60 year old metal roof that needs to be replaced. The pitch of the roof is unfortunately so shallow that the roof must be shoveled throughout the winter. The cabin is not insulated.

We like the idea of using anodized aluminum for the roof but are afraid it might not be able to stand up to all the shoveling. If anodized aluminum is not a good choice what would you recommend?

In Energy efficiency and durability | Asked By Stephanie Ulmer | Sep 5 15
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