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1 Answer

Mini-split v Package Unit Humidity Control; Sizing and Configuration

I have a 1920's house in Tallahassee, Florida - 2x4 frame construction with shiplap siding, no vapor barrier or insulation except in the attic and one wall that was installed later (originally a screened in porch), and a fair number of windows. I have sealed the floor and walls of the dirt crawlspace using heavy plastic with vapor-barrier tape at the seams, but there is still appreciable air flow between the foundation wall and the girders. The main floor is ~1,600 sq. ft.; approximately ~600 sq. ft. of the attic has been finished into a bedroom and bath.

Asked By Ellery Sedgwick | Jan 20 17
7 Answers

Radiant bathroom floor and auxiliary heat in the master of our PGH

Hi all--I've got a couple of questions regarding HVAC in my Pretty Good House (PGH). As you may recall, I built a PGH a little over a year ago and many of you contributed wonderful advice to my queries. We had a nice discussion on how best to heat my house and I decided to go with a single minisplit and a natural gas, heater rated fireplace. This system has worked well for most of the house, save the master bedroom.

Asked By Matt Mesa | Jan 16 17
6 Answers

Polaris vs HTP Phoenix for hot water and radiant heat

Looking at using either of those products for both hot water needs and heating (with coil/air handler) in a 3000 sqft house (slab on grade, 2 story, in Southern Ontario).

It looks like 70000btu would be sufficient, but I am wondering about the pros and cons of each tank. already know most features of each product, so I am mostly asking about anecdotal reliability issues with each brand (e.g. igniter issues on the Polaris, which may have been fixed by now).



Asked By Mai Tai | Jan 16 17
15 Answers

Lunos e2 ductless HRV system vs. ducted system

I am building a net zero house, 2000 SF, 2 stories. Can you tell me the pros and cons of the Lunos e2 ductless HRV system vs. a ducted system? The rep told me that 3 pairs of the Lunos e2 would be about right.

Asked By Courtney McCracken | Dec 8 16
6 Answers

Heat pump head unit locations

Hello all,

I'm currently building a small house in Vermont and I plan to heat it with mini splits. It's a 1300 square foot 2 bedroom ranch with an unfinished walkout basement. (See attached floor plan image.) The walls are 2x6 with fiberglass in the cavity and 2" of foam on the outside. The below-grade walls in the walkout basement will have 2x4 with fiberglass. The above-grade walls in the walkout will have the same assembly as the main floor.

I'm currently planning to have two outdoor heat pump units, one for the master suite, and one for the living room.

Asked By Ross Carlson | Jan 11 17
3 Answers

ERV - did I find a good buy or make a mistake?

My house plan is a simple, 1900 square foot ranch.

I purchased a Broan ERV, model 140 today. I could not turn down the price of $1187.75, shipped, tax-free. I thought this deal was "HUGE", spoken in my best Donald Trump voice.

However, I must admit that I did not do my homework on this unit before making the impulse buy.
I just felt it was a grat price and knew it would do the job per the numbers. So, using the formula here, 7.5 cfm per person plus 3 cfm per 100 square feet , I arrive at (7.5*2)+(3*19) = 72CFM.

Asked By Drew Baden | Jan 11 17
8 Answers

HTP Phoenix Light Duty paired with Lifebreath Clean Air Furnace (downdraft)

I want to replace the atmospheric water heater (interior to my house) with sealed combustion. I also wanted to replace the 80% furnace that sits right beside the WH interior to the house. I learned early from GBA that inside combustion is to be avoided.

Fast forward...I am looking at the HTP Phoenix Light Duty + Lifebreath CAF (downdraft). I am in the Seattle, WA area in a 1950's rambler.

Asked By S K | Jan 11 17
1 Answer

3 ach50

Is there a way to know what the infiltration will be in a house after it passes the test?

If an exhaust ventilation system is used for ASHRAE 62.2 requirements, how do you know that sufficient makeup air will come in through cracks to compensate for what is exhausted?

Asked By Kevin Mick | Jan 11 17
5 Answers

Mini-split for winter heating

My family has an insulated vacation cabin that is used in he winter ( zone 6
A). Normally it is heated via wood stove. Would it be possible (and smart ) to maintain the temperature of the cabin a 40F to 50F when not in use using a mini split heat pump. If the set pt is 50F what would be an estimate of the COP at outside temperatures of 40F, 30, 20, 10, 0, -10.
The cabin requires 9000 btus/Hr with an inside temp of 70F and outside temp of 0F. Would a floor mounted inside exchanger be better than a ceiling mounted unit? Currently when not in use the cabin is unheated.
Thanks, MainePaul

Asked By Paul Geisler | Jan 8 17
16 Answers

Solar hot air preheat for HRV/ERV

Has anyone seen a successful approach to using a solar hot air collector to preheat the intake air for an HRV / ERV?

It would be fairly simple to bypass the collector when preheat wasn't desirable.

One major concern is regulating temperature so excessive heat doesn't compromise the HRV / ERV.

It seems like it could be an ideal way to temper incoming air on cold, clear Colorado days (climate zone 6B), and get a little extra solar gain.

Asked By Pat Kiernan | Aug 17 16
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