Help me with garage exhaust fan

[t300]

Summary
- bought a new/1 year old house. sealed tighter than an Alabama tick.
- garage is 900sq feet, 12ft ceilings. floor heat. radiant heat fan/heater on ceiling. floor drains (poorly done)
- way too much humidity in garage. no garage venting at all. Garage door seals freeze up. We had a crazy humid early winter in Manitoba, unless I had windows cracked and fan heater on with dehumidifier it would sit close to 70%. Typically kept it around 15c. Humidity is a better now as the humid winter has calmed down but without me manually mitigating the moisture it sits over 60%.

Thoughts are something like
- keep air exchange under 10 minutes. for this size of garage that's 1600cfm or so. If I get closer to 5mins the CFM requirements go way up obviously.
- add biggest CFM exhaust fan that I can find, 12" depending how far apart wall studs are to make things simple. Maybe 14" which would typically give a lot more CFM. best location for this is around 8-10 feet up on north wall
- on some other wall, add passive vent in soffit and feed it into garage ceiling. I can see this being a bit of a PITA for a DIY'r like me, is this the preferred way
- humidistat control with override

That about right?

 

[Catchme]

Never was impressed with those fans through the wall. Looking at the same scenario as you and did a ton of reading. The inline duct fans people use for grow op’s is what I will be doing this summer. Diffuser in the ceiling, fan and ducting up in the garage attic and vented out through a vent in the soffit. The 12” quiet version does 1600 cfm and the controller can run off humidity levels or just on different speeds.

CLOUDLINE PRO T12, Quiet Inline Duct Fan System with Temperature Humidity VPD Controller, 12-Inch

Your source to create smart growing systems with components including advance grow tents, inline fans, clip-on fans, LED grow lights, and UIS™ controllers.

acinfinity.com

 

[X-it]

Dehumitifiers work, check your radon levels...if they are high midigating that have also been known to reduced moister levels.

 

[sirkdev]

Dehumitifiers work, check your radon levels...if they are high midigating that have also been known to reduced moister levels.

as long as your ambient temp is above 15C or so below that they dont work well in my experience

 

[t300]

Never was impressed with those fans through the wall. Looking at the same scenario as you and did a ton of reading. The inline duct fans people use for grow op’s is what I will be doing this summer. Diffuser in the ceiling, fan and ducting up in the garage attic and vented out through a vent in the soffit. The 12” quiet version does 1600 cfm and the controller can run off humidity levels or just on different speeds.

CLOUDLINE PRO T12, Quiet Inline Duct Fan System with Temperature Humidity VPD Controller, 12-Inch

Your source to create smart growing systems with components including advance grow tents, inline fans, clip-on fans, LED grow lights, and UIS™ controllers.

acinfinity.com

Thanks didn’t even think of that I’ll check it out

 

[rknight111]

as long as your ambient temp is above 15C or so below that they dont work well in my experience

You are correct, if its a regular refrigerant unit that is. An LGR will do a bit better, and a desiccant will work right down to 3-4 deg C, is the best however expensive and requires more maintenance. I would recommend purchasing a Drieaz LGR or a LGR unit from Abatement Technologies with a pump out. You may find some used ones but they may be a bit warm. The danby ones or consumer commonody versions are junk.

 

[sirkdev]

Interesting thanks

 

[rknight111]

DriiEaz https://www.legendbrandsrestoration.com/Products/Revolution-LGR-Dehumidifier

Abatement Tech https://products.abatement.com/usa/aquatrapr-200c-lgr-dehumidifier.html

Higher the temperature more moisture the air can hold ( Grains Per Lb) A LGR dehumidifier can remove 90° F/90% RH) 190 Pints/90L per day

Just some history on myself, I been in the flood and fire industry for 36 years and am considered a drying expert. I own a environmental company that works for restoration and insurance companies . We get called in to many interesting water losses and work with all parties to come up with the best plan to dry a structure.