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11 Answers

I have a new home under construction in NE South Dakota (cold Zone 6)

I have a new home under construction in NE South Dakota (cold Zone 6). Exterior walls are 2x6 with 1/2" 5-ply plywood.

My insulation contractor will be dense packing cellulose in the walls. He uses a 6 mil polyethylene for the netting. My concern is the netting is a vapor barrier, allowing very little wall drying to the inside, only to the outside. Your thoughts and comments would be appreciated, Thanks.


In General questions | Asked By Matthew | Jan 4 16
10 Answers

What's a cost-effective way to ventilate while maintaining winter humidity in a cold and dry climate?

I live in the high desert, and it gets cold in winter (there's some snow on the ground right now) but remains very very dry all the time. I've done a lot of air sealing work in this old house (last blower door test 5.2 ACH50) so that now, finally, when I keep all the windows closed and don't run the bath fan, the humidity naturally climbs to a comfortable 35-40%. However, with no mechanical ventilation, the CO2 level quickly climbs to over 1200 PPM and continues rising, so what I do to keep it down is turn on the bath fan.

In Energy efficiency and durability | Asked By Nate G | Jan 5 16
5 Answers

Mitsubishi multi-zone Hyper Heat models: true minimum output?

Take MXZ-8c48nahz as an example - the submittal indicates that the mitsubishi heating capacity goes from 7200 Btu/h to 54000 Btu/h for DB temperature over 5F. The NEEP spreadsheet with far more detailed spec indicates that the minimum is 27000 Btu/h instead.

Am I looking at two completely irrelevant number? If not, which one of this is the true minimum output capacity?

Thank you.

In Mechanicals | Asked By Anonymous | Jan 5 16
20 Answers

Attic moisture ...


I have read the articles on attic ventilation and moisture and believe I understand that at its core any attic moisture is typically the result of air leakage from the house and/or basement/crawlspace moisture.

Zone 5A.

In Energy efficiency and durability | Asked By Justin Brown | Dec 30 15
2 Answers

Mitsubishi 18,000 BTU Heat Pump Boiling/Bubbling Sound?

About one year ago I purchased a Mitsubishi 18,000 btu heat pump. It is the low ambient heating version...FE series i believe not the GE. Last winter was brutally cold (northeast pa) and never had in issue. Just last night it dropped to about 7 degrees F. For the first time I noticed a bubbling/boiling sound coming from the line set and primarily the indoor unit. Like I said earlier, I had subzero temps last winter and never heard this noise. The heat pump continued to deliver warm air and my home never got chilly. I've always heard if ain't broke don't fix/worry about it.

In GBA Pro help | Asked By Matt Noll | Jan 5 16
5 Answers

Water dripping from air conditioning supply vents

Hello I thought I had figured this out pretty easily the first time I noticed it.

There was a small puddle at the corner of my bed that I though might have been one of my lovely male pups leaving a present. As I was going to clean it up, I got hit with a drop from the air conditioning vent in the ceiling.

I chalked this up to my wife taking a shower in the master bath without running the fan. We tend to have higher humidity in our master bedroom because my wife prefers the door shut and rarely uses the bathroom fan during showers. I figured some warm moist air condensed.

In GBA Pro help | Asked By Mike M | Jan 5 16
9 Answers

Abandoning my floor heat with addition for mini-splits, does it make sense?

If you've read any previous post you may have seen I bought a house with hydronic heated (electric resistance, all electric home) floors that were "fully" insulated. I have proven since buying that there is no insulation in the floor and the tubes or more than likely at the bottom of a 6" slab.

This past year I added new windows and exterior insulation and I'm building an addition this spring. I am trying to decide how to heat and cool it. To me it almost seems like a no-brain decision to abandon the current system or just use it to try and temper the floor.

In Energy efficiency and durability | Asked By Mike M | Dec 30 15
6 Answers

Unique situation for a hydronic floor system

I am about half way through a whole house renovation of a 1888 2 story Victorian over a ventilated crawl space in New Orleans. We have been upgrading the insulation as we go with R36 closed cell insulation along the roofline in the conditioned attic and R3 zip sheathing and R15 mineral wool batts on the walls. I am ordering Indow-windows for the old single pane windows.

In Mechanicals | Asked By Mike | Jan 4 16
3 Answers

Long-term storage of rigid foam

I plan to use reclaimed foam on a REMOTE wall home with the build beginning in June. The insulation will likely not be installed until August. I live in a remote area and am not sure when a supplier may have a source nearby, so I want to get the order in early (now?) and hopefully not end up paying for shipping from a distant site. I have two concerns:

1. Has anyone in Central Maine had good luck with a reclaimed foam supplier on shorter notice? In other words, can I safely wait until closer to the install date to place my order?

In Project management | Asked By Jim | Jan 5 16
19 Answers

Insulating ceiling during winter construction?

Our house is currently at the stage where they are about to start interior framing. Unfortunately this means that there is a giant hole in the envelope (the ceiling!) and they are wanting to run temporary heat as it is quite cold (a typical daytime temperature this time of year is about 15F). Of course you can pump a lot of heat into a structure and not have it get too warm when you have no ceiling and a vented attic.

In General questions | Asked By Nick Hall | Jan 1 16
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