Recent Q&A

• 选择一个便携式热泵

  Recommendation on portable heat pumps? I'm looking to heat a few small workshop spaces that are detached (in a garage & in a barn). I do have a Mr. Buddy…

• Replacing AC with a Cooling-Only Heat Pump

  What are the options for replacing a ducted, cooling-only AC with a heat pump? If I'm understanding right, it's a new unit (with reverse valves, larger coils, etc.) but my…

• Heat Recovery from Dryer Exhaust

  Are there _no_ heat recovery products on market to recover the energy blown out of dryer vents? I found 2 prototypes online from the mid 2010s. One looks similar to…

• Window rail condensation & freezing

  What's a fix for condensation on glass near where the rails meet and frozen bits at the rail between the sashes for double pane, single hung windows? In other words,…

• New code option for cold floors

  Just read this on PNNL's site:"So the best way to construct a warm floor is continuous rigid insulation coupled with an airspace above the cavity insulation (see figure below)."And that…

• Reno: vented roof with 4 inch rafters. Spray foam?

  What are options for renovating an old (1940s) vented roof with 4" rafters? Contractor is recommending a 1st Phase of spray foam applied from underside to get R20 (and I'll…

• New multi-split: modulating?

  How does one 'let the mini/multi-split modulate'? We're new multi-split owners, after reading lots about them on GBA, but a common recommendation on efficiency that I don't understand is the…

• Do you recognize this insulation?

  Recognize this insulation? There are 2 types I've found. Is the one covering the attic floor look like blow in cellulose? or vermiculite? And the one that's like a sandwhich…

• Meta analysis of deep energy retrofits – anyone else seen this?

  While browsing the depths of the EPA and DOE's website, I bumped into a nationwide meta analysis of deep energy retrofits (DERs) in 2014 done under grant by one of…

• Older house energy audit recommendations – conservative?

  Hi GBA folks, We received our report from a home energy auditor and my question is: are these target goals conservative? or limits of an older house? Hoping folks can…