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9 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:

In General questions | Asked By Clay Whitenack | Aug 23 16
3 Answers

New roof cost? Upgrading from a low slope to a steep slope

I live in Ontario Canada. Im considering all my options to improve my old home's attic space. You see, we get lots of ice damming each winter. The existing roof has a 3/12 pitch along with an 8/12 cathedral. Im wondering if it is cheaper to have a contractor build a new steeper pitch roof over my existing (or remove the existing for the steeper one).

In GBA Pro help | Asked By Jake Rabe | Aug 21 16
8 Answers

Safer grout option?

Our tile contractor wants to use TEC power grout. Since this is an epoxy grout, I am concerned that it contains BPAs. I would really like to avoid BPAs in our home as much as possible. Is there a safer grout option out there? Preferably no VOC and BPA free. Thank you!

In Green products and materials | Asked By Carolyn Farrow | Aug 24 16
2 Answers

PEX manifold systems

Is there any reason to use a manifold system on the cold supply side besides the convenience of maintenance on fixtures?

In General questions | Asked By Ross Williams | Aug 24 16
1 Answer

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.

In Building Code Questions | Asked By Matthew Stewart | Aug 23 16
2 Answers

How to insulate a workshop?

Planning on having a 60’ (L) x 30’ (W) x 12’ (H) post and frame (pole building), built in climate zone 5B. The building will be bisected by a 2x6 interior wall so that 36’ x 30’ will be used as an un-insulated garage and the remaining 24’ x 30’ will serve as an insulated and conditioned workshop. The floor will be 4” concrete slab on grade poured after the building is erected. Exterior walls are metal panels mounted to wall girts and the roof is also metal on engineered trusses.

In General questions | Asked By Ken Hodge | Aug 23 16
1 Answer

Ceiling fan efficiency with 25-foot ceiling

We are in the process of building a house with 12' sidewalls and a vaulted ceiling. The ceiling height from the floor will be about 24'. The area below this fan will be 728 sq. ft.

A local salesperson stated that a ceiling fan (in a vaulted application) will not adequately move air even with a 72" down rod. We were going to purchase a 68" diameter fan.

I do not feel the person in the retail position may be giving the correct information. Any assistance would be greatly appreciated.

In General questions | Asked By Jeff Larson | Aug 23 16
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.

In Mechanicals | Asked By Erica Downs | Aug 12 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.

In General questions | 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);

In General questions | Asked By tim brown | Aug 17 16
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