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2 Answers

NEW mini-split from it here?

I read here (I think......could be wrong though since I have been everywhere on the net looking for answers before I settled here).. that Mitsubishi was going to release a multi-head ASHP this year (2015) that is still efficient to -25c in an effort to tap into the US residential heating market.
Is it here? Is it coming?

Asked By tim brown | Feb 2 15
3 Answers

Adding A/C to 1918 built home

My husband and I own a 1918 built foursquare home. We currently use a single 8000 BTU window A/C unit to moderate the worst of the summer heat in our zone 4 climate (Minneapolis). We have discussed installing a split A/C system or small duct central A/C system on the first two floors our home. I think I have a good grasp on the split A/C systems but know less about the small duct systems. I like that the small duct systems have less impact on the look of the house. From what I understand, attic installations are fairly common with these.

Asked By Brian Forney | Jan 31 15
7 Answers

Freeze risk for a heat pump water heater in an unconditioned garage

I have an unconditioned garage with a gas water heater in climate zone 5B. The garage is unconditioned, but insulated (R-15 whole wall, no slab edge or sub-slab insulation), and obviously has some exposed plumbing in it. Right now, the temperature in the garage doesn't get low enough to present a freeze risk, probably aided by the water heater's standing pilot light and hot metal flue. But if I replace it with a heat pump water heater, the unit's going to be continuously cooling the room, right?

Asked By Nathaniel G | Jan 31 15
7 Answers

Code Required - Electric Resistance Heater

Zone 4 - My building code department is requiring a heat source in all the bedrooms even though I am building a super air tight, super insulated home (way above code). I have a ductless mini split in the adjacent room and I leave my doors open but the building dept still wants to see a "heating source" in that room.

Makes no sense to install another minisplit unit in a small room so I want to get past code inspection by installing an electrical resistance heater. What is a good brand/type to install? Can I just install one of those wall mounted fireplace units that put out resistant heat?

Asked By Peter L | Jan 31 15
3 Answers

HRV removing too much humidity?

I have an issue that I hope to get help on. I just built a 3300 sqr ft. home in lower Michigan. The home has 6" exterior walls that are insulated with 1" of closed foam followed by high density fiberglass insulation. Windows are high efficiency resulting in a very tight envelope. In an effort to address IAQ, I had a HRV installed. What I am struggling with is maintaining a desirable humidity level (~35%). Currently my HRV is triggered during any fan call from our geothermal unit. I am struggling to get the humidity above 20%.

Asked By Derek Jamieson | Jan 31 15
4 Answers

Combining electric cove heaters with PV

In a recent blog, Designing an HVAC System for a Cold Climate, Malcolm Taylor is quoted as recommending electric cove heaters, and a link to the Comfort Cove line from Radiants Systems, Inc. is provided in the blog text. Searching Green Building Advisor turns up half a dozen other references to cove heaters, all very short, and all positive. I wonder if there is more useful advice on choosing and using this technology for supplemental heat.

Asked By Derek Roff | Jan 29 15
2 Answers

I need to replace my gas furnace

Hello to everybody at GBA.

My gas furnace and AC system is starting to get old and I'd love to replace it with a heat pump. As I already have ducts, it seems to me that a ducted system would be best, but I can't figure out if that would really work.

Asked By Martin Holladay | Jan 26 15
8 Answers

Wall vent vs. roof vent

We are installing a custom wood range hood and can't decide between venting through our wall or heading through the roof. The duct is 6" round. Going through the roof the run would be about 3-4' straight up. Roof is pitched about 5-12 and the vent cap would land right around 30" from the eave.

The range sits on an exterior wall, so heading though the wall would give the run a 90 degree turn and about 2' of ducting. The siding is 4" lap fiber cement. Any pros or cons or suggestions to persuade me one way or another?

Asked By Matt Cibula | Jan 25 15
2 Answers

What's the best way to integrate rain water to a condo system?


First of thank you for having such a wonderful forum to share infornation on. I have found this place very usefull in the past.

To my question: im designing a 7 story medium sized condo that will house 6 families. Im thinking of integrating rain harvesting to the building as we some times get droughts and i hate to see all that rain water go to waste. I think it should be regulation to have some sort of backup water sytem just incase the mains dry up. But for now will just be using rain water for the watering closet.

Some numbers:

Asked By Osman Naskali | Jan 24 15
22 Answers

Best HVAC for a 1,100 sq. ft. passive solar house at 46 N latitude?

We are building high-performance, all electric, 1,100 sq foot passive solar home in cold weather winter climate with hot, humid summers. Slab on grade. Exposed concrete floor as thermal mass. Natural gas is not available. Winter temps infrequently reach -20 to -30 degrees range in December and January. We will use modeling to size heating and cooling system. We will have two bedrooms, open living, dining, and kitchen (primary solar gain area). In addition, there will be a full bath, 1/2 bath, mudroom, and mechanical room. Heating days the last 3 years: 7,065; 8,980; 9,799.

Asked By Randy Bunney | Dec 26 14
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