Community: Mechanicals

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

The usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration:
Under the box labeled "More explanation," look for the words "File attachments."
Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


5 Answers

Heating bathroom and attached closet

We are beginning a long and expensive endeavor to update a 100 year-old house in the Seattle area and first on the list is updating two small bathrooms. The previous owners of the house installed an efficient Buderus boiler a few years ago, but unfortunately the radiators in these rooms have been long been removed. They are currently heated by a few wall-mounted electric space heaters which I would really like to rip out. Unfortunately, I can't seem to get a straight answer from any heating contractors as to how to heat the space adequately and efficiently.

Asked By Corey Vanhove | Oct 28 14
35 Answers

Seeking an air-to-water heat pump

I'm looking for an air-to-water heat pump and feedback from those who've used them. We have a LEED for Homes project in Victoria, BC, perfect climate for heat pump, affordability of project prohibits groundsource for 36Kbtu heat loss of 1800 ft2 home and for optimal comfort, low temp/efficiency, to avoid ducting we're selected hydronic in-slab for heating distribution thus standard air-to-air heat pump is a no-go.

Asked By Allison Ashcroft | Jul 28 09
11 Answers

Minisplit - One indoor unit for two adjacent rooms?

Do any of the minisplit manufacturers offer a wall mounted indoor unit that will service two adjacent rooms? I'm considering a minisplit to replace the gas furnace and a/c in my 1300 sq. ft. single level home in zone 3A (mixed-humid). Without a shared indoor unit on the common wall between two bedrooms, I might need five indoor units. The multizone minisplits seem to jump from 4 to 8 zones and the price jumps too. I understand the technical problems with one wall unit serving two rooms, but have any of the manufacturers solved them.

Asked By Steve Robertson | Oct 23 14
4 Answers

Installing ductless minisplit over refrigerator

Building an 800sf 2 story house, main floor is 400sf open floor plan. Would there be any problems if I were to install the ductless mini split head above the refrigerator?

I was thinking of mounting it on the front of the soffit so it would be flush or slightly proud of the front of the fridge, allowing it to spread air down without hitting the fridge. It would also be further from the coils on the back of the fridge. I read that it should be 7-10" below the ceiling.

Asked By Tom Frisch | Oct 28 14
1 Answer

What's the best wall height for a ductless mini split heat pump?

Hello out there,

Asked By Theresa Spear | Oct 26 14
3 Answers

ERV, HRV, Dehumidifier retro fit before finishing basement

Hi all, I'm new here. Please bear with me with lots of questions.

I live in Zone 4A, with humid summer (100+ F, at least 3-4 months AC time), cold winter (-10 -- 0 F, at least 3-4 months heating), and wet spring and fall. Our house was built about 10 years ago. It has 3 HVAC systems for 4000 sq. ft. and additional 2000+ sq. ft. unfinished basement. Two HVAC systems are located in basement while the third one located in a closet on 2nd floor.

Asked By Wendy D | Oct 25 14
8 Answers

Calculating how much air needed to even out temps for minisplit

I'm building an 800sf 2 story house, R20 under slab, R40 walls, R60 roof, as airtight as possible, but likely just double pane windows (due to cost). 12% glazing, mostly on south side, w/ 4" slab on first floor. Using Marc Rosenbaum's heat loss spreadsheet, I get around 4000BTHU building load here in Portland Oregon at the 97% coldest day of 23F and a design temp of 70F, so a delta T of 47F.

Asked By Tom Frisch | Oct 23 14
6 Answers

Thermostats with radiant floor heating

I recently read an article comparing forced air and radiant heat energy use. The finding showed that the folk with radiant heat set their thermostats higher than for forced air. I hope that I am not being silly, but how can a thermostat on a wall respond to radiant heat? If one put a metal foil around the thermostat ,but let air flow occur, would the thermostat read a different number? I read in Mr Lyles masonry stove book that a cathedral that had radiant heating only had a 2 degree difference between the floor and ceiling (75 feet up).

Asked By Mike Legge | Oct 12 11
2 Answers

Rated output for electric radiant ceilings?

I've been searching the web for a rule of thumb to calculate the rated output for a 40 year old electric radiant ceiling system. Must be some rule of thumb like 10 btu per suare foot......but I can't find it.
Thanks

Asked By Walter Gayeski | Oct 17 14
2 Answers

Best integrated system for water heating and radiant floor heating?

I'm looking to remodel my home and install radiant floor heating system. Can anyone provide any information on good heat sources (boiler, water heater, etc) and system arrangement (direct, indirect, closed loop, etc). Is it okay to combine DHW with radiant heat or is there some over arching reason why they should be kept separately?

Home details: Just south of San Francisco, 2500 sqft, two stores, 5 zones, Warmboard S floor board, mostly covered with hardwood flooring.

Asked By Dmitriy Khazansky | Oct 17 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!