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12 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
3 Answers

Polyiso sandwich with synthetic underlayment

I'm located in Central Texas (China Spring, TX) and am building a house with my wife. The house was originally started by the previous owners and we are replacing and redoing quite a bit of it at the start. We are doing the majority of the work ourselves (taking forever) and we are at the point of finishing the roofing

Asked By Jacob Cox | Aug 24 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).

Asked By Jake Rabe | Aug 21 16
0 Answers

Paint removal using soda blasting off of soft brick is damaging the brick exterior.

Thanks for all the informative info on this site. I'm owner of a 100 year old former wagon factory built with soft brick - known in Wisconsin as Cream City brick which is notoriously soft. The previous owner had painted the building many times. As discussed, trapped moisture in the brick causing spalling, etc. Right now we are trying to gently remove the paint using a soda blaster. Soda blasting is supposed to be one of the gentlest of methods of paint removal.

Asked By Brian Burns | Aug 24 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!

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?

Asked By Ross Williams | Aug 24 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
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.

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.

Asked By Ken Hodge | Aug 23 16
4 Answers

Spray foam the ceiling joists vs. the back 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
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