Community: Mechanicals

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8 Answers

Mini-Split & Generator vs Wood Stove

Hi,

I'm about to build a house about 8 miles outside of Brockport, NY (near Rochester). The lot has electricity but no gas. I would like to heat my house off mini-splits, and I'm currently having a Manual J done to determine feasibility. The footprint of the house almost guarantees that I will need more than one small mini-split rather than one central unit. I plan on having a backup generator.

Here's the question: Should I put in a wood stove for backup heat, or simply put a small minisplit on the generator?

Asked By John Ranson | Feb 17 17
6 Answers

Whole house dehumidifier - where to install?

I am currently building a 2 story, 5400 sq ft home in Alabama where humidity is often high. We will install a whole house dehumidifier ("WHD") as part of the HVAC system. We will have 3 HVAC units (2 and 3 ton down, 2 ton up with variable speed air handlers and 2 stage compressors). The installer is proposing to install one WHD (for entire house) on the larger of the downstairs unit which is also the unit that will control the kitchen and great room areas. The master bedroom/bath and another downstairs bedroom/bath will be on the other HVAC unit (no dehumidifier).

Asked By Richard Marks | Feb 14 17
4 Answers

Multi-speed inline exhaust fan

Is anyone aware of an inline exhaust fan that has multiple speeds so it can do low continuous ventilation and on-demand ventilation?

--John

Asked By John Ranson | Feb 12 17
12 Answers

Engineer ambushes salesman, or "what do we do about HVAC?"

So at this point, I have done a Manual J load calc for my house that puts the heat load at around 20,000 BTUs. I know that I want an electric heat pump so I can eventually go net zero. I *think* that I want it to be the Bryant Evolution 280a, which has the highest HSPF (13) that I've been able to find in a ducted heat pump. Seems simple enough, right? "Quote me an installation for this unit."

But so far I have been unsuccessful in getting any HVAC companies to bid. Not one. Four salesmen have come by, and no bids. Zero.

Asked By Nate G | Feb 7 17
8 Answers

HRV for wet room exhaust: Will I have to build a motorized damper box myself?

I currently own a 2006 Lifebreath HRV 155cfm unit in SouthWestern Ontario. It was ducted well enough, but it basically pulls from too many areas of the house (kitchen, laundry room, 3 bathrooms). It does a good job of whole house ventilation, but basically it feels underpowered for wet room exhaust (1850sqft 2 story, with unit in basement, so some runs are also quite long, all flex).

Asked By Mai Tai | Feb 8 17
3 Answers

Vents to roof or wall?

Need some advice. I have to run new vents for a dryer 4", a bathroom vent 4", and my kitchen downdraft vent 6". All are nearly in the middle of my house so the closet location to vent to is my roof, which I'd rather not do since it is a tile roof and introducing more spots for leaks cannot be good, and all vents will be in the most visible part of the roof from the ground.

Asked By Jimmy Black | Feb 8 17
13 Answers

Heating and A/C

I am building a new home in zone 5. I received a quote for our heating and a/c and I wanted to see if they meet my goals of efficiency and appropriate sizing. Here are the specs on our house:
1792 square feet plus full basement

Asked By Michael Brackett | Jan 30 17
4 Answers

Sense Home Energy Monitor - Initial Thoughts

A few months back someone asked about electrical load monitoring tools. I promised that I would give feedback on the Sense Home Energy Monitor once I had a little time with it.

Here are a few initial thoughts after a month of use. (I don't know anyone at Sense or have any financial interest in the company.)

Sense is already changing my lifestyle. A few examples:

Asked By Andrew Bater | Jan 28 17
16 Answers

Does Geothermal with slab on grade construction make sense?

We are in Minnesota (Zone 6a). Building new this summer on 12 acres. 2000-2400 sq/ft single level (maybe a bonus above garage), slab on grade, with radiant floor heat. Shooting for a 13-15kw grid tied PV. We are looking at Geothermal and have a good site for it, but I'm not sure it makes sense in our situation. I'm hoping not to run duct work just for AC (since we will have radiant), but I think I would have to ducts with Geo to get the benefits of AC. Would putting the money into more insulation, or solar make more sense in this case?

Asked By Scott K | Jan 30 17
4 Answers

ERV ducting question

I'm building a house in SC and plan on it being tight enough to need mechanical fresh air. I was planning on using an ERV and would rather not have the Panasonic grille so I was going to put a unit in the cellar. I'm struggling with ducting. In reading Martin's article where he discusses this very topic in FHB issue 248, I wanted to ask, why could you not tap into your return ducts for exhaust and then tap into the supply trunk line for fresh air delivery. Would this not operate very similar to the fully ducted system described as the most efficient?

Asked By Chip Radford | Jan 29 17
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