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28 Answers

Two backdrafting appliances and dust — Do I need an HRV?

Hello, I have a problem with my house.

1) My house is probably air-tight

2) My water heater backdrafts whenever the bathroom fan is on. It's probably backdrafted every single morning (windows fog up & I feel the warm air at the flue when it kicks only stops once turning off the bathroom fan).

3) Opening specific windows in the basement relieve the backdrafting of the water heater.

4) There was a lot of dust on a return-air duct that was right above the water heater. Another supply duct near the water heater had rust.

Asked By J Pritzen | Nov 26 15
5 Answers

Wood smoke pollution causing health problems

We have just about finished renovating when we discovered that my wife is now sensitive to some odours, especially wood smoke. She can react to it long before I notice it.
Currently, we have a two stage mid-efficiency furnace with a 5 inch duct bring combustion air into the furnace room.
I can replace it with a high efficiency unit to eliminate the combustion air duct. I can keep all the windows and doors closed so that less smoky air comes in. I can ensure there are dampers on the dryer vent, range hood, and bath fans.
But how do we get fresh air into the house?

Asked By Aaron Gatzke | Dec 4 15
16 Answers

Ideal load for a multispeed inverter-driven GSHP?

In a planned "Pretty Good House" in Mixed Humid, Northern Climate Zone 4, I intend to use a 45 EER Ground Source Heat Pump with 3 inverters (loop pump, compressor, and fan) with a Cooling Capacity range from 9,000 - 24,000 Btu. I wish to have the lowest Peak Cooling Load, that utilizes the equipment most efficiently, while providing dehumidification and keeps short cycling to a minimum. Approximately what sould that theoretical Peak Cooling load be ?

Asked By Ted | Nov 19 15
1 Answer

Do I require a fresh air intake for my fan coil (forced air system)?

I have a Bosch in slab heating system in the basement and the upstairs is heated with a fancoil. Heat is derived from my domestic hot water system which is also heated by the Bosch Boiler. Why would I need, or do I, nedd fresh air to the fan coil?

Asked By Ron | Dec 1 15
2 Answers

New HERS rated home: Issues with Trane XL HVAC heat pump constantly calling for heat

Hello guys. Looking for some advice on our new home . Small custom home completed earlier this year. 2 x 6 walls. Single-story. Designed for energy efficiency from the get-go ...

1792 square footage living space. 9 foot ceilings. 2 x 6 exterior walls framed with California corners and insulated headers and insulated wall leads.

Complete spray foam encapsulation. Spray foam walls. Spray foam roof deck, and crawlspace is insulated with spray foam. Crawlspace is insulated to an R-15, walls R-22, and roofline is considered R-38.

Asked By Wayne | Nov 30 15
2 Answers

Recommendations for a small HRV

Hi everyone
I'm looking to buy an HRV for our small (1000 sqft) ranch home.

I already installed all the dedicated ductwork last year and had been using a home-made HRV that worked very well, but I don't have the time to keep tinkering with it to get it to work just right. The cabinet was made of plywood and I kept having problems with the air streams crossing and causing condensation and mold in the cabinet.
Anyway as a result I'm going to hook up a new HRV to my ductwork.

I'd like a small unit - I will be installing it in a closet
Quiet would be good
Also with ports on top

Asked By Carlo Giombi | Oct 12 15
2 Answers

Locating manifold of a radiant floor heating system

Recently acquired a Condo that has propane fired radiant floor heating system. The house inspection showed it to be working. Recently as the cold weather begins in earnest the system cannot keep up... had a local reputable company diagnose the problem which they determined is caused by air in the system. They were able to remove some of the air at the boiler. As they drained water from the system it was very brown. In any case, the heating improved in some of the rooms as measured at the floor with an infrared thermometer. But not all. The thermostat was replaced with a programable model.

Asked By Carroll Ayer | Nov 28 15
2 Answers

Using well water for air conditioning

A random thought occurred to me while I was thinking about the Chiltrix system. For air conditioning, water at about 55 degrees would be circulated through the fan coils. That is about the temperature of the water coming out of my well all year. If the system was only used for air conditioning, could the well be the source of the cold water as opposed to running a compressor? I don't see a problem with this idea, but I expect that if it was simple at least some people would be doing it. Am I missing a major flaw?

Asked By Reid Baldwin | Nov 21 15
3 Answers

Desuperheater water heater

I always understood that if you had a GSHP with a desuperheater, that your water heater should be an electric tank type. A client we are designing a home for would prefer a gas tank over electric, and our MEP engineer has not suggested that this would create any issues. Please advise.

Asked By Heather Gayle Holdridge | Nov 19 15
3 Answers

Zoned HVAC and dampers — Opinions?

Townhome has a zoned (3-levels) HVAC system. This system contains four trunk lines off the supply plenum one of which contains a weighted (manually adjusted) damper that was originally routed back into the supply plenum. This weighted damper is designed to provide bleed off air when less than 3 zones are in use.

You would adjust the damper by so that is operated as follows:

3-zones in use (damper is basically closed)
2-zones in use (damper partially open)
1-zone in use (damps is slightly more open vs 2 zones in use).


Asked By Chris M | Nov 18 15
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