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7 Answers

Why is my brand new HRV filled with water?

We did a DER in MA recently (complete September 2015). Part of the mechanical system design includes a Zehnder 350 that is designed to run 24/7 on medium flow to have sufficient air exchange. We have really high heat right now and high humidity. I noticed just now that it was making a strange noise. I opened up the cabinet (following the instruction provided) and found the right side (leads to the house air handlers) was full of water. There is a condensate outlet drain on the left but there is no way for water to get from the right to the left.

Asked By Erica Downs | Aug 12 16
0 Answers

Venting bathroom through a flat roof

I am interested in learning if there is guidance or code that would cover venting a bath fan straight up through a flat roof. Our state's Weatherization Field Guide indicates that vent terminations shall not be allowed on flat roofs. My interpretation is that you are not allowed to place a fan vent termination on a flat roof. It also indicates that on sloped roof the termination should be elevated 18". There seems to be a lack of what is an acceptable venting configuration for a bath fan when you are forced to go through a flat roof.

Asked By Matthew Stewart | Aug 23 16
9 Answers

Critique my Mini Split placement options

Hi all,

I am down to crunch time and getting close to pulling the trigger on HVAC strategy. Before I "bite the bullet", I want one last pep talk. I think I have the upstairs figured out, but I'm concerned exactly as to where to place my heads.

I have posted two mini split layouts below. Let me know what you think. I have included the room to room BTU loads as well.

Asked By Clay Whitenack | Aug 19 16
4 Answers

XPS insulation around HVAC duct

I have a cabinet in my kitchen and one in each bathroom that has toe kick registers. The HVAC air/heat vent comes out at the floor under the cabinet, but not directly to the vent. I do not want to remove the cabinet and have limited acess to it. I am noticing condensation in the sub floor in these areas, I assume because of condensation due to the entire floor under the cabinet being cooled. My idea is to cut strips of xps 1 inch or so insulation to lay on the floor to insulate the floor.

Asked By don gilbert | Aug 23 16
12 Answers

What would you do?

Forgive me for the vague title and the long post but I am lost in possibilities... all expensive!

Oh and its complicated because I am forced into a decision NOW that will heat my 850 sq ft house AND be adequate to heat in a year (or two) when I add 1000 sq ft. The math gets fuzzier when I tell you the plan is to add 4 inches of EPS to ALL the exterior walls (including existing) and 6 inches under the NEW basement concrete).

No one here (Canukistan) is able or willing to do a manual J to size a unit for a two fold job...

I live in Kenora Ontario Canada (zone 7);

Asked By tim brown | Aug 17 16
8 Answers

Help me bust this comical manual J calculation

Calling all energy nerds. Double check my math. I have a manual J calc in my hands with some weird results. I could go over every little error (some obviously intentional), but you have seen these kinds of things before. What I want to talk specifically is heat loss through the wall. His report does not show the design temps, so I am trying to work backwards through the calculations to figure it out. That's where I need your help to double check my thinking.

The inputs:

Asked By Clay Whitenack | Aug 23 16
16 Answers

Ice damming — Low-slope roof — Resolvable or hopeless?

[ SUMMARY ]

I own an older home in Ontario Canada that may have been built between the 1920s to 1950s. It originally had knob & tube wiring.

Each winter I have to deal with ice damming along 2 sides of the roof, no where else. The areas in question are a Low-Slope roof (3/12 pitch, east & west side of the ridge) and a Cathedral style roof (8/12 pitch -- inside the home there is a sloping ceiling that is covered by drywall). See a photo of the home: http://imgur.com/sXUzfzG.

Asked By Jake Rabe | Aug 19 16
3 Answers

Spray Foam ceiling joists vs backing of the roof sheathing?

Is there ever a time when an attic space is so large that it is better to spray the ceiling joists rather the backing of the roof sheathing?

(No cathedral or vaulted ceilings…)

The home is ~6000 sq ft under roof (including garages) the builder is thinking that it is better to spray the ceiling joist since the attic space is so large.

(There are areas were the ridge row is ~15+ ft above the ceiling joists.)

His logic is why  do I want to cool the attic and that my electric bill will be higher since I’m heating/cooling a larger area.

 

Asked By Cynthia Richards | Aug 23 16
3 Answers

Embedded floor joists air sealing

I have a 1960's bungalow in Canada where the 2x10 floor joists have been embedded/cast into the concrete foundation wall. The foundation wall stops about 1" below the floor sheathing.

I have been considering insulating the rim joist area but because of the embedded joists I don't feel this is a very good idea because of the potential for the joist ends to rot in winter. It seems the best option is to leave that area un insulated.

Asked By David Red | Aug 23 16
8 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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