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3 Answers

Best source for domestic hot water?

Getting ready to build a LEED certified home, tight construction, excellent quality windows. Ground Source Heat Pump based HVAC. Will use excess heat from heat pump for hot water, but need a storage/booster tank. HVAC contractor wants to use standard resistance tank heater. Is this sufficient? How do I best find a highly insulated tank? Essentially no one in my area of the country (Northeast Indiana) is building like this. Heat Pump tank?

Asked By Andrew Katz | May 9 14
7 Answers

Will a single ductless mini-split heat pump be able to distribute its air evenly throughout my house?

I am in the middle of a deep energy retrofit of my 1,200 sf New Mexico house, and a manual J calculation of the projected loads once my projects are completed shows an estimated heating and cooling load of only around 13,000 BTUs each, compared to the current baseline of 41,000 heating / 28,000 BTUs cooling.

Since this is such a small number, my existing 125,000 BTU furnace will become even more ludicrously oversized than it is now. So on everything is done, I'd like to replace it with a single ductless mini-split heat pump.

Asked By Nathaniel G | Jun 13 14
2 Answers

To keep basement warm - keep away from heat pump water heater?

We are building an energy efficient home (ACH 0.8 or better at 50 pascals) and I want to avoid a water heater heat pump because I want to put my shop in the basement and I don't want to lower the temperature in the basement. Am I thinking about this issue correctly considering the energy these heat pump water heaters save? We plan on a net zero energy home using solar. stuartkrantz@gmail.com/954-732-3347

Asked By Stuart Krantz | Jun 12 14
12 Answers

Small ducted heat pump?

My wife and I are 69. We're in the process of designing a house for our retirement with our architect. It's going to be a "pretty good house" with a very small heating/cooling load. Neither my wife nor I think the ductless minisplits are all that attractive, AND the air filters would be hard (relatively, because of the height) likewise for the "ducted" minisplits that I've found via Mr Google. ( they're all ceiling mounted and we'd like to avoid having to get on a step ladder to change air filters as we get older & older).

Asked By Roy Goodwin | May 29 14
11 Answers

Replacing a natural gas gravity furnace in an upgraded small older home

I am a regular reader here and have learned a lot on this site. Thanks to all who contribute.

I have been upgrading the thermal envelope in a 960 square foot house in Detroit, Michigan for several years. I have injected polyurethane foam in the walls, R60 cellulose in the attic after air sealing, 2" XPS on the basement walls, and 2" XPS in the joist cavities in the basement. The windows are single pane but with caulked in place storm windows.

Asked By Gregory Worrel | Jun 1 14
6 Answers

Personal experiences with Daikin Quaternity ductless heat pumps

I've read many times about the independent humidity control of Daikin's Quaternity models. I've even found myself jealous of them after installing a Mitsubishi and feeling muggy in my house on a mild spring day when there is little need for cooling, and the dry mode makes us feel too cold. There are illustrations and videos on the web showing how it works -- the indoor coil is split into two parts, one of which can be hot and one of which can be cold (at the same time), which allows for dehumidification without cooling.

Asked By Nick Welch | Jun 10 14
4 Answers

HVAC help!

I am a homeowner with a 3500 sq ft. home in New York. 10 years ago I purchased an American Standard 16 seer ducted HVAC system. When temperatures go below freezing I have to back up this system with baseboard heaters. Some of my baseboard heaters are newer and some are very old (and probably extremely inefficient). I would love to have a net zero house but I’m not sure if this is possible. Last year I added insulation to the basement and attic. I have solar water heater which is fantastic. I also have sunpower solar panels and wood burning stove that can heat 3000 sq.

Asked By Randi Gustafsson | Jun 9 14
7 Answers

Should I expel my ventilation system air onto my hybrid heat-pump water heater? Should I vent the WH into my crawl space?

For a superinsulated house being extensively retrofitted in South Jersey (R-40 walls, R-70 attic, triple pane windows) with a permanently wet crawlspace (riverfront, high water table), I am considering positioning the exhaust duct from the Fantech heat recovery ventilation system to expel over the top of a hybrid heat pump hot water heater. The HWH will be in the insulated unheated 2 car garage, possibly next to a geothermal water-to-air heat pump. I would plan on turning that exhaust vent away from the HWH in summer.

Asked By Michael Arnold | Jan 22 13
3 Answers

Ductless mini split sizing advice - Mitsubishi specific

We are going to have a Mitsubishi heat pump installed in our house (in progress) soon and would be interested in some thoughts on sizing.

The house is in Jackson, NH 03846 (climate zone 6a). It's cold and snowy, but we have great passive solar gain, open floor plan, tight construction, and high insulation values. We have wiring in place for regular electric resistance backup. Our Energy Star rater calculated our heat load at 11.2kBTU / hr at design temp (-6F, 65F inside, based on St Johnsbury VT).

Looking at the new Mitsubishi FH line, MSZ/MUZ units:

Asked By Brian Post | May 23 14
14 Answers

ERV or Central fan integrated ventilation best for hot humid climate?

I read an article by Martin Holladay who said ERV could actually make the situation worse in hot humid climate during those days when temp and humidity level are mild. That confused me. I would appreciate answers to questions about the best vent. system for a new build air tight house at approx. 2200 sq ft, in zone 3A below the red line. Heat pump HVAC system.
1. Why might an ERV make matters worse on mild days with low humidity?

Asked By rob clark | May 23 14
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