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2 Answers

How were the IECC Climate Zones maps developed?

Were high resolution zone maps developed and then adjusted to match the county boundaries—perhaps with a generous safety margin—or something different entirely?

My brothers' houses, 150 feet apart, are in different counties. One house is in Zone 3 (Johnston County, NC), the other in Zone 4 (Harnett County, NC). Should my Zone 3 brother be concerned that he's really experiencing Zone 4 conditions (and vice versa)?

A generous safety margin might imply that some true zone 3 climate locations are well into Zone 4 map areas which can have a large impact on those with a tighter budget.

Asked By Stewart Akerman | Sep 2 15
6 Answers

Attic insulation upgrade

I'm struggling with getting the correct answer on how to proceed with upgrading my attic insulation.

I live in Pittsburgh PA climate Zone 5A.
My existing attic space has batt insulation on the floor with no air barrier and is vented at the gable ends.

I would like to spray foam on the underneath of the roof deck sheathing in-between the truss joists and on the gable end walls to meet the required R38.

I'm struggling to understand if I should use open cell foam or closed cell foam.

Asked By Forrest Watson | Sep 1 15
2 Answers

Building Codes

I often see posters refer to building in areas with no codes. Here in Canada, although we have areas in which there are no permits or inspections, the building codes are enacted to cover the whole of each province or territory. People building in areas where the codes are not enforced have the same obligations to follow them as elsewhere.
Are there areas in the US where there are no codes and you are free to build as you like?

Asked By Malcolm Taylor | Sep 2 15
2 Answers

New 20+ SEER Variable Carrier heat pump w Greenspeed Intelligence system creating moisture and performance problems in the crawl

I had to replace 2 -13 SEER HVAC split systems in my house about 2 years ago do to some Sandy storm damage. One split system was a 90% gas furnace with a 3 ton 13 SEER AC and the other was a 2 ton 13 SEER heat pump. Both the air handlers were originally in the crawlspace, which I hated, and I wanted to come up with a better set up with the new replacement systems.

Asked By Bruce Howe | Sep 2 15
6 Answers

How can I properly vent my tiny house roof (it has cross member framing instead of rafters)?

I have the framing almost complete on my tiny house, but I have run into a stumbling block. Framing the roof with cross members instead of traditional rafters made a lot of sense because the shorter span allowed smaller lumber for more head space and less weight, but upon further research my plan for venting is not going to work (I know - proper planning prevents poor performance). See attached picture for framing structure.

Asked By Ryan Reed | Sep 2 15
5 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.

Asked By Charlie Sullivan | Sep 2 15
12 Answers

Why is there condensation on the return ducts and mold in the attic as well 60% humidity throughout the home?

This home has since been remodeled, including all new metal duct work and insulation. The issue that we need to resolve is the high humidity in the house at about 60-65% even though the unit is running efficiently. There is quite a bit of condensation on the return ducts in the attic as well. We have had two reputable Heating and Cooling Contractors come to assess the situation to no avail. The owner attempted to contact the original Mechanical contractor, but has not been able to speak to anyone yet.

Asked By Jimmy Miller | Sep 1 15
22 Answers

Skipping radiant floor heat in a passive house?

I'm building a house with (conservative numbers) R 60 walls and R90 ceiling. The windows are in-swing casements with double seals. The floor is going to be stained concrete on 2" insulation. I had 2 consultants tell me that I will not need radiant floor heat it will be too much. We will have a whole house air circulation system and a gas fire place. I am worried about not putting in the pipes in the floor and then being wrong. I am considering just putting in the heated floor under the rooms away from the fire place. I could add a heater to my whole house ventilation system if needed.

Asked By Jenz Yoder | Aug 25 15
5 Answers

What mechanical system makes the most sense?

I am in a zone 4a Kansas City Missouri. In the heat of the summer it can get up to 95 with high humidity and it doesn't cool down at night.

We are building a 3500sqft ICF house with R-24 walls. (We have the labor and resources for it to be the most affordable option) and a R-60 SIP roof, cathedral ceiling. We are thinking about building with a 4' crawl space, unvented, 20 mil vapor barrier. Our windows and doors we are sourcing from company's in the U.S. which build to the PassivHaus standard.

I have a few questions:

Asked By Jordan Schiele | Sep 2 15
4 Answers

How to reduce the humidity in my home?

I live in a 1200 sq ft. mobile home and heat with electric space heaters. I do not tolerate forced air due to severe chemical sensitivities (it is propane), so all grills and ducts are blocked off. The humidity in my home runs between 40 - 50 % which is too high. I keep it closed up tight to keep out wood smoke and dryer sheets from the many close neighbors that I have. I am interested in the eGO for my laundry room, and wondering if the air coming in and out can be filtered with more than what it comes with. I am also open to other suggestions.

Asked By Suzanne Lippuner | Sep 1 15
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