# Q&A: A Forum for Green Building Experts and Beginners

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### Dirty electric from minisplit ductless heat and air conditioning

I saw a u tube video on a Fujitsu mini split system air/heat...where a building biologist specialist was testing a persons house for dirty energy. He found from the box on the outside of the house had very high amount of electro magnetic interference... and determined that it came from a Fujitsu Mini Split system... he used filters to try to eliminate the energy...which worked for everything but the Fujitsu System. He said the spikes were the same type that causes occular melanoma cancer.

Asked By Arleendv | May 30 18

### vinyl siding recycling

I found your map for vinyl recycling but i live in Greeley CO. and it appears there are no recyclers in this area. Any suggestions??

Asked By patj47 | Jun 23 18

### Roof vent size for vaulted ceiling

Hi
I'm building a garage with a vaulted ceiling and at the point where i need to vent the roof. I see there are formulas for calculating attic ventilation but i can't find a formula for calculating a vaulted ceiling.
Should I measure sq. ft. of each roof side and add both sides to get the total sq ft? For example, my roof is 25' long and 10' from wall plate to ridge. This is 250 sq ft per side bringing the total to 500 sq ft to ventilate.
So i'm thinking i can now use the formula which says i need 240 sq in at the soffit and 240 sq in at the ridge???

Asked By Nepal | Jun 22 18

We are in climate zone 6a in a fairly dry climate. Outside humidity varies between 20% and 35% I would say on those dry days. Our home is going to of a good enough design with R-30 walls and R-60 roof with ACH50 around 1.5 and I'm unsure if I will go with triple or double glazed windows.

Asked By Steve Mackay | Apr 4 18

### Unvented roof — vaulted ceilings — moisture, rot, etc.

Im hoping someone can steer me in the right direction for an issue Im having with my current roof.

As best I can describe here is the situation

Full home remodel completed in 2015 including 2nd story addition and brand new roof.
Home is in Southern California about a mile or so from the beach
Vaulted Ceilings exist in every bedroom, however the problem seems to be localized to one side of the house where there is not attic space, no venting.
Canned lights exist in each room, they are just standard cans IE they are NOT fully enclosed/sealed

Asked By Meyersrl | Jun 22 18

### Most efficient way to run Mini Split ACs

I'm currently cooling ~1900 sq feet home, 2 floor Colonial zone 5, with an AOU24RLXFZ hooked up to a 12K wallmount @ top of open stairway, and a 7K in the master BR which is 1/2 of the second floor. I'm very impressed with the cooling abilities so far as Boston has seen some days close to 90. I keep the stairway unit at 71 (1 degree offset in function settings), and BR is at 72 in economy mode, but on low fan so it is always running quietly (fan makes annoying ticking noise in auto fan mode). Entire home +/- 1.5 degrees of 71.

Asked By kjmass1 | Jun 22 18

### Conventional heat pumps with mini-split low temp efficiency?

There seems to be quite a few options for extra high efficiency heat pumps when you go with mini-splits, but I am struggling to find conventional heat pumps that stand out. It will be connected to a standard ECM motor air handler, like a normal a/c unit would. The ducting is basically in the plans, so there is no going back now.

Asked By Mai Tai | Jun 22 18

### Do I need to use R10 minimum on the roof deck in climate zone 4C in all cases?

I am detailing a low slope unvented roof. I will be using spray foam & then batt insulation to total R38 under the roof deck in Climate zone 4C. I could meet code just with that but would like to use rigid EPS board, R6, on top of the roof deck to prevent thermal bridging. This introduces a third insulation that is not covered in the code
- Do I need to use R10 to meet the minimum above deck value? Does this rule still apply since I'm using spray foam directly below the deck?
Thanks, Andy

Asked By user-7003242 | Jun 22 18