Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 04-21-2009, 04:34 PM   #16
Newbie
 
Join Date: Apr 2009
Posts: 12
Rewards Points: 10
Default

Ductless Heat Pump for Garage??


Sorry for delay in responding. Had considerable trouble sending Garage Plans. 5 in all. Please go to this link......
http://s679.photobucket.com/albums/v...ittlediabetic/


My biggest concerns are Heat Source as heat will be sucked out with the exhaust fan in cold weather. I had originally wanted to incorporate an electric or propane construction heater behind a bank of intake filters to warm incoming air from outside vent. It would have to be used only after vapors have been removed from garage. As well, it is important to be able to close (insulated) vent to outside when not in use to stop heat loss and cold air from coming inside. The same concern is for the exhaust fan at the back of garage and how to insulate the ducted vent when fan is not in use????

Beenthere, (OR ANYONE) can you provide any insights to my dilemma?
All assistance is greatly appreciated. Thank YOU.

brittlediabetic

brittlediabetic is offline   Reply With Quote
Old 04-21-2009, 04:40 PM   #17
Newbie
 
Join Date: Apr 2009
Posts: 12
Rewards Points: 10
Default

Ductless Heat Pump for Garage??


Please scroll down to see descriptive text directly below each of the 5 plans.
brittlediabetic is offline   Reply With Quote
Old 04-21-2009, 06:14 PM   #18
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,025
Rewards Points: 3,714
Default

Ductless Heat Pump for Garage??


Whats the CFM of the exhaust fan?
beenthere is online now   Reply With Quote
Old 04-21-2009, 07:37 PM   #19
Newbie
 
Join Date: Apr 2009
Posts: 12
Rewards Points: 10
Default

Ductless Heat Pump for Garage??


About 3,500 CFM. This is another area of controversy. Pro spray booths of similar size as garage area use tube axial fans of 10 - 12 thousand CFM. A U.S. fan supplier who purports to have decades of spray booth experience says 3,000 is adequate for this room.
brittlediabetic is offline   Reply With Quote
Old 04-21-2009, 08:35 PM   #20
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,025
Rewards Points: 3,714
Default

Ductless Heat Pump for Garage??


It probably is.

At 3500CFM.
In order to maintain an indoor temp difference of:
Temp---BTU
----70------264600
----60------226800
----50------189000
----40------151200
----30------113400
----20------75600
----10------37800

Those are the numbers if the exhaust is going to be running for more then a few minutes(5).

After that, the building and its contects will start dropping in temp quickly.

So what indoor temp do you want to maintain while painting. And how long do you expext to run the exhaust at any one time.
beenthere is online now   Reply With Quote
Old 04-22-2009, 12:02 PM   #21
Newbie
 
Join Date: Apr 2009
Posts: 12
Rewards Points: 10
Default

Ductless Heat Pump for Garage??


A few months ago, in early December, it was necessary to spray base coat - clear coat urethane (candy apply red) on both rear quarter panels and rear bumper of a Blazer I had repaired. The temp was just above freezing, overcast sky. Painting under our open carport, suddenly the wind picked up and wet snow landed on my first coat of base. Could things get worse! Momentarily the weather changed. I gently blew all traces of water off the surfaces, continued with additional coats then clear. That job turned out as well as if it had been done in a paint booth. Painting can sometimes be very forgiving but not always! The lesson learned: "it is possible to spray in below normal temperatures."

In my proposed garage, when using urethane, temperatures can drop dramatically and still be ok. When spray has been removed from area, heat can be turned on and garage can warm up. Soon the whole continent must use water based paints so I understand they use portable electric heaters.

I've really been wondering if I will need a similar sized fan to pull in intake air, or if just an opened ceiling vent will supply enough air to the exhaust fan at back of garage. Also the size of the intake vent, and do I really need a plenum for the exhaust fan. Would a plenum more quickly remove spray contaminents? A plenum would allow for a bank of filters in front of it, but wouldn't it be as effective to have just one filter in front of exhaust, and change the one filter each time I paint?
Fans suggested include the Jenny fan, 18" explosionproof, which is a square unit about 18". http://www.steamjenny.com/fans/explproof.html
brittlediabetic is offline   Reply With Quote
Old 04-22-2009, 03:42 PM   #22
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,025
Rewards Points: 3,714
Default

Ductless Heat Pump for Garage??


Doesn't need a plenum per say.

A hood, or frame that opens toward paint area is fine.

A motorized intake damper should be all you really need, not a intake fan. Since your not using the garage for 2 things at once.

I would interlock them, so the exhaust can't run unless the intake damper is open.

Keep in mind. That once the building temp has dropped. It will take a while to reheat it, and the car/parts your painting.
Can't just use a normally sized heating system.
beenthere is online now   Reply With Quote
Old 04-22-2009, 10:36 PM   #23
Newbie
 
Join Date: Apr 2009
Posts: 12
Rewards Points: 10
Default

Ductless Heat Pump for Garage??


Now I'm finally getting somewhere. Glad I found you been there. Would you think a 20" x 20" intake vent in ceiling would be big enough or would you go wider across the room between roof trusses? Back to heat source, perhaps Yuri hit the nail on the head also with his recommendation of a Reznor and propane. Not crazy about any gas heating, however, was hoping for some suitable electric source.
brittlediabetic is offline   Reply With Quote
Old 04-22-2009, 11:03 PM   #24
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,025
Rewards Points: 3,714
Default

Ductless Heat Pump for Garage??


Your fan needs low static.
So you'll need a larger opening for the intake vent.

Trusse width, by 4 foot.

As long as your flammables are in the proper storage locker(explosion proof).

A propane heater isn't aproblem.

I'd put the heater near teh intake, so it conditions the air a little before it gets to what your painting.
beenthere is online now   Reply With Quote
Old 04-23-2009, 03:16 PM   #25
Newbie
 
Join Date: Apr 2009
Posts: 12
Rewards Points: 10
Default

Ductless Heat Pump for Garage??


I plan to put intake furnace type filters over the ceiling vent to catch any airborne dust drawn inside garage. If I mounted the heater inside a metal box could I put some sort of inflammable filter material in front of it several inches away to further reduce any dust within the heater from blowing out?

One more question before I go. Regarding placement of the exhaust fan at the back, would it be better to mount the fan through a hole in the back wall and connect an elbow turning upward into a stack pipe extending just above the roof or I would prefer to do the same manoeuvere on the inside of the garage but this would require two elbows - the first to turn, say 90 degrees right
- the second to then turn 90 degrees upwards through the roof

Two elbows would further restrict the airflow, but would it really be an issue here?

Is it unwise to go through the roof due to the likelihood of leaks down the road, instead exiting through the wall?

Once again, I'm indebted for your genorisity of advice. Thank you kindly.
brittlediabetic is offline   Reply With Quote
Old 04-23-2009, 03:28 PM   #26
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,025
Rewards Points: 3,714
Default

Ductless Heat Pump for Garage??


The effect of the pipe, will depend on the size fan you use.

Those fans have low static ratings. So you may have to use a larger pipe then you originally planned, in order to get your required air flow.

Don't mount a box/filter system for the unit heater, unless you get one that is designed to have duct work.

The normal fans aren't strong enough to pull through air filters.

You may want to get a slightly larger exhaust fan. And connect a speed controllerto it. So you can use the pipe system, and adjust the air flow with the speed controller.

Only real problem with going through the roof. Is, its another hole in the roof.

beenthere is online now   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to test apartment Heat Pump tbrubes HVAC 7 02-04-2009 04:05 PM
Heat Pump Woes Zenica HVAC 50 01-27-2009 08:37 AM
Heat Pump vs Aux Electric Heat batolson HVAC 16 01-17-2009 11:28 AM
Testing FuelMaster 21 Module? Heat Pump no Run. thehotrod11 HVAC 3 12-29-2007 03:11 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.