Community: Mechanicals

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10 Answers

Fan coils and return air from framing voids

Dear Advisor,

Asked By Dan Cullen | May 23 16
8 Answers

HRV selection

Finishing up a zone 5 pretty good house ~4000 sq foot home with a wall stackup of (exterior to interior) 2" XPS (taped/staggered seams) -> 1/2 inch plywood -> 2x4 wall with R-15 roxul. Heating with traditional forced air. We have separate ducting for an HRV pulling air from bathrooms and mostly returning in bedroom closets and a few other spaces. The original plan was to use a Fantech 2005R 82/204 CFM with approximately 75% apparent sensible effectiveness.

Asked By Michael D | May 20 16
2 Answers

Calculating furnace efficiency

I know (or at least I think I know) that to figure steady state efficiency, divide the BTU output by the input. But many furnace spec plates don't have a BTU input listed. Instead they'll have Gallons (or Litres) Per Hour. Now, if 1 gallon of residential fuel oil has about 138,500 BTUs, can you do a straight calculation using these numbers?

The example I've got in front of me right now is a Kerr Gemini furnace (K5RE-115) with a Riello Burner. 96,000 BTU/hr output, 0.85 USGPH input. Nozzle size is 0.75. Can somebody help me figure the efficiency of this model with this info?

Asked By Peter Rogers | May 19 16
2 Answers

Hot water closed loop at 135 degrees F

Hi , I have set up an anaerobic digester at my horse property , I have made a solar heater ( black hosepipe behind some upvc ) to heat it ,for best results I need to get the digester up to max temp 135 deg F , just had my first pump seize up , what of off the shelf pump can cope with that kind of temp , its running water around a closed loop of hosepipes

any and all suggestions welcome

Asked By David Lowe | May 19 16
19 Answers

Working a wood stove into my hot water system

Hi all,

I'm looking for thoughts on how to tie a wood stove into my DHW system in a new house I'm building. Some background is needed though...

Asked By Jay Hersh | Aug 9 11
4 Answers

How exactly does this Carrier ERV work? Is it any good?

Hello, I'm working with a contractor putting together a plan for air sealing, insulation and a new furnace. For ventilation, he is suggesting a Carrier "comfort" series ERV. This unit has no separate control panel, it simply runs whenever the furnace fan is running, and it connects ONLY to the return trunk of the furnace system, either directly to the furnace cabinet or the return plenum/duct.

http://www.carrier.com/residential/en/us/products/indoor-air-quality/ven...

I found the install manual here:

Asked By Zach H | Apr 30 16
6 Answers

Mini split head - mounting location considerations

I'm interested in feedback on what must be a common dilemma with mini splits - where to place the indoor head unit when the best location for aesthetics, function, proximity to the outdoor condenser unit, and gravity condensate draining are often in conflict with each other.

I'm most interested in opinions about how much weight to put on a location that will not require a condensate pump - what are the issues there - but decided to open up the question further as these various considerations are probably a source of struggle to many people.

Asked By david jensen | May 11 16
8 Answers

Minisplits and moisture removal effectiveness

Considering that the better variable refrigerant flow mini split heat pumps, sized properly, are designed to operate largely without cycling off, it would seem that they would offer superior latent load performance (moisture removal) over the typical cycling split system. Is that true in the real world? I'm specifically interested in performance in high humidity environments like here in central Florida.

Thanks.

Asked By David Jensen | May 8 16
15 Answers

Using far infrared heating for in-floor heating of a house

I came across a product....Geo Dream carbon film .....at the GreenBuild 2015 Conference in Washington DC and I am interested in anyone's comments about its use and performance. I have spoken with the North American supplier ....located in Vancouver BC... and some of their installers and everyone speaks very highly of the product and the fact that it can be used as the sole source of heating for the home. We are building an ICF home in Climate Zone 5 and are quite interested in using the product.

http://www.geodreamheat.com/

Comments welcome! Thanks.

Asked By Jonathan Scholl | May 9 16
14 Answers

How does efficiency in a mini-split vary over various operating levels?

It is my understanding that a SEER rating is determined by simulating the operation of a particular make/model air conditioner over a hypothetical season, presumably assuming various temperature and humidity levels throughout the year.

Asked By david jensen | May 3 16
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