Portable A/C unit?

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Originally Posted by jeepinbanditrider

I'm tempted to go in the attic with some ducting and add a piece to go to the garage's crawlspace hole lol.

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This is the route I'm planning to go now, but I don't want to have just a vent like in a normal room that I close or put a magnetic sheet over to shut it off. I would like to be able to seal it off at the start of the spur so the ducting to the garage never has cold air in it unless I want it to. I just need to look into how to do that without getting a separate condenser. Still thinking it will be a winter project so I am good to go next summer, so I have some time.

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Originally Posted by jeepinbanditrider

I'm tempted to go in the attic with some ducting and add a piece to go to the garage's crawlspace hole lol.

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If you do add a duct, be sure and add it off of the main plenum. You don't want to steal air from an existing duct for sure. It will also (obviously) take air away from the existing ducts no matter what.

It would only be open during work in the garage. I would just need to find a way to shut it off I assume that there are duct's that have shutoffs in them or something along those lines.

you could either close the register, or install a true cut off in the duct. the closed register will still let some air bleed through.

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Originally Posted by patf

you could either close the register, or install a true cut off in the duct. the closed register will still let some air bleed through.

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Info on the true cut off? That's what I would want to do. is it something easy enough to buy and install yourself? Just wonder into Home Depot or Lowes and pick it up? Or is it something special that I need to get from a professional and have him install?

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Originally Posted by Rob®

Info on the true cut off? That's what I would want to do. is it something easy enough to buy and install yourself? Just wonder into Home Depot or Lowes and pick it up? Or is it something special that I need to get from a professional and have him install?

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Here is one

http://www.mcmaster.com/#duct-fittings/=8flp8h

They have others you will just have to look for the one you want.

I know nothing about it.

I just tryed the link, the dampers start on the next page.

Linkie:Grainger.com

Thanks for the links, guys! The motorized ones are much less than what I was thinking. This project might get bumped up a bit now. :happydance:

I still question if a single vent plumbed of the main A/C unit is going to get you enough cooling to do any good.

Heck I had the garage door open between the house and garage with a fan going and it just barely made a difference. YMMV

Guess were going to find out lol.

This is my advice so you can take it or leave it, but I have tried almost everything you guys are throwing out there.

First forget the window unit in the attic or even suspended from the ceiling it's simply not going to work efficiently in a large un-insulated space. Hell I bought a window unit when our main AC went out and it could barely keep our master bedroom cool. Your biggest problem is that A: your cheap and B: your cheap :D. Seriously you will not be able to find an AC unit that will run on a standard 15amp circuit that is going to cool that space nor will you find a TCB unit that will do the job. Now you may have limited success with using one of those portable units that vents to a window if you vent it to the attic if you are able to keep it aimed at you. This won't keep the garage cool but it MAY keep you cool.

You may also have limited success with running a separate duct from your main AC to your garage, but you will need more than one vent and consider this the thermostat is located inside your house so the unit will not run long enough to cool the garage.

Ultimately to do this successfully you need to install a separate unit that is properly sized and I would suggest either the a ductless system or a vertical PTAC. Either one should work well with the PTAC being slightly more cost effective.

Like I said I have tried it all and I'm currently using a MovinCool Office Pro 18 which works decently but it's not going to make it 75 degrees on a 100 degree day. For this I had to add a separate circuit and vent it to the attic space. I have also insulated the ceiling and garage door of my garage. In our next house I will most likely install a vertical PTAC as I feel it is the best solution for a garage HVAC system.

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Originally Posted by Flyin96M

Your biggest problem is that A: your cheap and B: your cheap :D.

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It is like you know me! ::Banana::

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Originally Posted by Flyin96M

This is my advice so you can take it or leave it, but I have tried almost everything you guys are throwing out there.

Like I said I have tried it all and I'm currently using a MovinCool Office Pro 18 which works decently but it's not going to make it 75 degrees on a 100 degree day. For this I had to add a separate circuit and vent it to the attic space. I have also insulated the ceiling and garage door of my garage. In our next house I will most likely install a vertical PTAC as I feel it is the best solution for a garage HVAC system.

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Thanks for the help!

The only thing not insulated in my garage is the door, and that is obviously going to be done before or at the same time as I get AC in there. So I'm covered there. I have the door sealed when it's closed right now - I can't see any light around the edges when the door is closed.

I was thinking this would be about a $1500 project, and was fully prepared to spend that in the future. If I can get away with spending a 3rd of that to get the garage to 80° on a 100° day now, I am all for it - I don't need, nor especially want, to have it 65° in there.

Looks like I'll have to decide if I want to give the ideas here a shot first or call a pro and be done with it when the time comes. Thanks for the advice!

I believe Flyin96M has confirmed what I said. :clap:

Anybody try an evaporative cooler for the garage? NH had some portable ones on in the Garland store and they felt pretty good.

I insulated my south facing garage door early this spring with 3/4" rigid foam with a foil backing on one side (R5 insulating value). I cut squares to fit the door and installed them with foil tape and was sure to leave an air gap between the steel of the door and the foam panel to minimize conduction. That alone was worth 10-20 degrees when the door is getting full sun.

I've got the material to put a flexible foil bubble wrap (R3.2 or something) over all of that but haven't gotten around to it yet, and to finish up the project after I was considering a high volume exhaust fan - It may be good to run that for a few minutes to exchange excessively hot, wet air before cycling the cooler, and it would definitely be beneficial in dumping extra heat loads after rolling in a hot car and closing the door if the whole garage is very well insulated.

My wife took pity on me and picked up a DeLonghi 13000 BTU portable cooler that was on closeout at homedepot.com last week. I was working in the garage yesterday getting it rigged in and got it fired up - outside temp was showing 102, garage temp showing 91, and the portable cooler was able to pull it down to 87 by the time I finished up the work I was doing. Not at all uncomfortable.

One thing to be careful of is oversealing your garage - if there is no place for air to move , the garage itself will create a positive or negative pressure zone and will start forcing air from where ever it can. Moisture, heat, garage chemicals, and other stuff may end up going somewhere you don't want it to go through the path of next lowest resistance that was never a design consideration.

I personally wouldn't put a garage trunk on the main AC system because of all of the chemicals, flammables, and other smells that are usually found out there. An automated damper to do the garage or the house would be good, but I wouldn't mix the air between the garage and the living area.

Chris

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Originally Posted by bigDstars

Anybody try an evaporative cooler for the garage? NH had some portable ones on in the Garland store and they felt pretty good.

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Yes and it didn't work. Want to buy mine?

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Originally Posted by bigDstars

Anybody try an evaporative cooler for the garage? NH had some portable ones on in the Garland store and they felt pretty good.

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Originally Posted by Flyin96M

Yes and it didn't work. Want to buy mine?

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We have 14 of them where I work and I hate every last one of them. The floats get stuck regularly and the watershed grids need constant cleaning. They don't cool well in the tropical conditions we have here. To work good, they need to have a humidity below 20%, otherwise the water will not evaporate well. I have felt evaperative coolers in West Texas and they work really well, just not in Dallas. The ones in the Home Depots and the Northern Tools are going to feel cool because they are blowing cooled air to begin with.

I'll make some comments. you can either listen to my opinion as someone in the HVAC business or ignore me. My wife ignores me all the time, so it wont hurt my feelings if you do. :) Window shaker in attic ducted to garage space to be cooled wont work for two reasons. The blower in the window unit is not designed to work against the static pressure that the air ducting will add to the ssystem which means very little air will be supplied to the space. Your attic is likely 120-140 degrees so the window shaker will be running way less efficiently and with way less capacity than it is rated at. Typically an air conditioner's rated capacity is at 95 deg outdoor, 80 degree dry bulb indoor 67 degree wet bulb indoor. The hotter the ambient the a/c is in, the less the capacity and efficiency it will provide. Window shaker suspended from the ceiling in the garage and sitting in the space you are trying to cool. Wont work because you are just dumping whatever heat you remove from the space with the evaporater right back into the space with the condenser. Running a duct from your home HVAC to the garage. The thermostat in the house wont sense the garage temp. It will operate based on the house temp. Even with a dampered system, there is still a chance that not only odors that your wife would find objectional will creep into the house but also a high potential for dangerous things such as carbon monoxide poisoning can occour. I don't believe it is acceptable to building code to even have a set up of that nature where you are mixing that space with a living area's air distribution system. And yes, i know it is temporary and it is your own house etc. It's still not a good idea to do it. Your home HVAC has a set amount of air it delivers to the rooms in the house. If you pull a duct off or tap off into the garage you are basically taking that air away from the house. All of that said, it really wouldnt be any better than buying a 12k btu sopt cooler from Home Cheapo and using it in the garage. Typically you would only be trying to have a spot cooling affect anyway like on a manufacturing line in a factory wehre they just blast cool air on a spot where a worker stands or sits. Sure, cooling the whole garage would be ideal. Someone mentioned a budget of $1500 to do the tap duct and damper thing. You can buy a few of the portable units for that much and they would be more effective in the long run. The most ideal way would be to have a dedicated system for just the garage. If you are like me, that's really not feasible $$ wise. What you might consider is a PTAC unit. A PTAC is one of those low profile through the wall units you see in every motel room below the window. That would mean cutting a sleave area in the side of your garage. You could somewhat hide that from a HOA with some creative shrubbery placement. If you insulate your garage walls, ceiling and doors a 12k system is going to serve you well. for most of us, we probably arent going to try and hang meat in there or anything.

Bringing back this old thread considering the current weather.

Any updates on the best way to add temporary A/C to your garage? Like others, I have an HOA and a windowless all bricked garage so window units are out.

My garage door faces west so I get the afternoon/evening sun and it is not an insulated door. Finally no insulated walls and ceilings. Couldn't get much worse. I added a ceiling fan but it doesn't do much more than move the hot stagnant air in the garage around. Outside is cooler than my garage sometimes!

Suggestions?