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1 Answer

More wet fiberglass

Some of y'all might remember this picture...
http://techno-fandom.org/~hobbit/hse/myduct.jpg
and the discussion that went around it, concerning careful backoff
[from the wall] and sealing-up of the outer duct sheath to make sure
no water infiltrated into the fiberglass between. This was for the
intake duct on my HRV setup, the coldest part, and after retrofitting
same on my HRV setup accordingly it was fine all this winter.

So I was downstairs putting the snow shovels away [wishful thinking?]
and happened to bump the end of the *exhaust* side duct, which

Asked By Hobbit _ | Mar 31 15
19 Answers

Fresh air distribution for hydronically heated house?

Currently have a leaky hydronically-heated house.

I plan on removing the siding, installing blueskin VP peel-and-stick, then 2 layers of Roxul R6 ComfortBoard IS from the roof right down to the footings.

Because this should really improve the air leakage, how should I get fresh air in/out of the house to control humidity / air quality / etc?

Do people run a set of air ducts throughout the house from a HRV?

One of the appeals of using hydronic heating is that sound / dust transmission is significantly reduced.

What would you recommend??

Thanks!
.../j

Asked By John Charlesworth | Mar 26 15
3 Answers

Manual J - Calcs - Mini Splits

Zone 4B - 3,300 sqft - 2 story - R10/R25/R60 with R8 windows - open floor plan design

The calcs came in at 3.25 tons heating/cooling. Two ductless minis per floor:
3 - 9,000 Btu Mitsubishi Hyper Heat Pumps - 26 SEER - 10.5 HSPF
1 - 12,000 Btu Mitsubishi Hyper Heat Pump - 26 SEER 10.5 HSPF

$12,000 installed (P&L) for all units - 10 year warranty

Asked By Peter L | Mar 26 15
22 Answers

Mitsubishi mini split behaving very differently with external thermostat vs. without

I am able to monitor my home's electricity use and I always thought it was a little weird that my Mitsubishi FE18NA heat pump seemed to constantly be spiking up and down, considering that the whole idea of the inverter-driven compressor is that it can run smooth and steady... fast forward to yesterday when I received my MHK1 thermostat and hooked it up. Suddenly, the power usage was steady as a rock.

Asked By Nick Welch | Jan 6 15
6 Answers

Filtration and humidification with mini-split systems

I have a customer with allergies. Her existing GFA furnace has a high efficiency filter and a humidifier.

In the new (air sealed and super insulated) home we are designing for her, we are planning to use Fujitsu mini-splits for heating and cooling and a Honeywell ERV for ventilation. Specs for these units indicate a washable filter but no MERV rating.

Asked By Terry Herschberger | Mar 23 15
3 Answers

Foil tape inside duct?

I have several heat registers that I can access the duct from the inside only on, a few as far as 2 feet into them. Some just have seems, one has a good 1 inch gap on one side. (I'll try to hammer that together from the inside.)

Anyway, I've read that mastic can dry out on the inside of ducts, but have read conflicting suggestions about foil tape. I have this tape right now, should it work on the seems inside the duct, in the last 2 or so feet before the register?

http://www.homedepot.com/p/Nashua-Tape-1-89-in-x-50-yd-322-Multi-Purpose...

Asked By Jeremy M | Mar 23 15
7 Answers

Makeup air advice needed

I had a recent post asking advice regarding HRV vs exhaust only ventilation for my very tight energy efficient smaller home that I am building. Balanced HRV systems if installed properly could have exhaust lines in the bathroom and in the kitchen with boost capacities negating the need for additional exhaust lines.

The major stumbling blocks are the very high cost of proper installation and space requirement for the system itself for easy accessibility as well as space for the duct work.

Asked By Victoria Williams | Mar 22 15
4 Answers

Is anybody aware of an hybrid air-source heat pump and gas boiler available in U.S. market?

I know Daikin makes one for the the European market, but I can't find a similar product that is available here.

Asked By Joseph Carry | Mar 21 15
8 Answers

Water-source heat pump sizing

My 2-ton Carrier water source heat pump needs replacing. It's a condo, so I own the heat pump & handler, but not the water loop. I think I'm going to replace with another Carrier, but I'm considering downsizing to a 1.5-ton unit.

Asked By David Hicks | Mar 19 15
9 Answers

DVHP on Southern Maine Coast

We are building a new home: 2,200 s.f., three floors living, southern exposure, closed-cell foam, R-40 and R-60 +-, radiant heat (I know, my wife insists), HRV, little propane stove.

We are seriously considering an AirGenerate ATI66 for hot water.

Here's my thinking:
Summer, run a supply duct from second floor, exhaust to first floor living area;
Winter, supply and exhaust from outside;
Shoulders, supply and exhaust from outside.

Asked By Peter Whitman | Mar 18 15
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