Question about Air Conditioning?

[Ruthless53]

I'm just starting to build out my garage so I have a workshop at home instead of having to go to our hangar to play around. Fairly new in this world as I have recently figured out how much I enjoy building stuff (mainly with wood). I have in the past couple months built my dad a pole barn (no sides) so he can put his trailers and junk under, a shed off the side of our small hangar to cover his fuel tank, and a home office desk for my wife. It really is a great outlet for my mind as I tend to have a hard time shutting it off at home. I'll post up a couple pics of what the sheds and desk.

I have really enjoyed reading this forum and the information has been extremely helpful. My question to yall is about putting ducts in for a portable ac and if it would be beneficial or not. I'm 6'4 and about 280 (played offensive line in College) and tend to sweat small puddles when im out in the garage in the Texas heat and humidity so ac is important to me enjoying my time out there. I got a smoking deal on a MovinCool Classic 10 ac off Craigslist a few days ago. Only paid $300 bucks for it and it works great!! The amount of air it puts out compared to other portable AC's i've seen is truly impressive. For $2,700 new i would hope it would.

http://movincool.com/portable-air-conditioners/classic-10




Would it be better to put in some ducts around the garage to spread the air out more or just leave it coming from the nozzle only? My idea is to mount duct work going from the machine up the wall to the corner of the ceiling and then around to the end of my main work 30 feet total. The duct at the machine is a 5 inch duct and on the specs it says the max run is 40 feet. The unit pushes alot of air and cooled my garage off fairly well last night with the garage door opened 2 feet or so to put my vent out. I have to cut the exhaust vent into the door still so once that happens I can keep the garage closed up and it should really work well. I'm going through the man door because the exhaust hose is a whopping 12 inches and it will be easier and cheaper to replace the man door than the siding and sheet rock that a 12 inch hole will mess up. The garage is insulated just the same as my house and the garage door is insulated with R5 rigid insulation but not 100% sealed up around the edges.

Here is a sketch of what I have planned for my garage and the spots where I think the ducts would be beneficial. Its kind of hard to read since I compressed the picture size so it would post but the square by the bottom door is the AC and the arrows are pointing to where i would like the ducts.

 

[Ruthless53]

Here's a couple picture of the pole shed I built for my dad. 33 wide by 28 ft deep. I had one kid helping me. And had a total if 3,500 or so in materials and roughly $1,000 paying my helper.

 

[Zeke]

40' of 5" duct has a lot of resistance because the air speed is higher in a smaller duct. They must know what they are basing their specs on but I would upsize any duct for the run and then put the air out through the correct register. And that seems like a pretty big unit to be throttled down to 5 inches. I bet you could put a wye on there and get some air over to your area as well as the shop in general.

I see you can download the manual if you provide an email. Of course that's extortion to me but if you need it....

 

[pseudorealityx]

The actual outlet of an A/C unit is never right size to actually duct it out. You would want to expand it to a 10" round if you want to do any real ducting.

Also, if it's a single exhaust pipe, you need to provide a path for make up air. Which is why these types of units can't shake a stick at even a normal window shaker.

But as long as you're happy.

 

[Ruthless53]

The actual outlet of an A/C unit is never right size to actually duct it out. You would want to expand it to a 10" round if you want to do any real ducting.

Also, if it's a single exhaust pipe, you need to provide a path for make up air. Which is why these types of units can't shake a stick at even a normal window shaker.

But as long as you're happy.

Since the garage is not completely air tight would this be less of a problem? I have the ability to put a return air plenum on it and run another vent outside if that would be better but I would prefer not too unless its going to make a big difference.

I have also made some changes and built a shelf up high and set the unit on it. It will only be about a 20 foot run at most and probably only about 10 feet. I will definitely go with the bigger duct and I will also go with insulated as I've read about the condensation drips with sheet metal down here in the south.

 

[Random Guy]

Not hooking up an intake duct to the outside for the condenser section is basically like putting a box fan in a window while running the unit. I'd find a way to run both an inlet and exhaust hose for the thing.

 

[Ruthless53]

Ok final question for now....there are two intake vents on this. The one in front sends air over the evaporator coils and the bigger one on the side sends air over the condenser coils. Do I just need to vent the one that goes over the evap coils or should both be vented to draw air from the outside?

 

[Random Guy]

You want the evaporator intake to pull air from inside, and the condenser intake to pull from outside.

 

[nsula_country]

When I worked in a wood mill we had a trailer loads of these things. We used them in the summers as point of use coolers for operator stations. They have a condensate container you have to dump periodically while running the unit. I believe they are designed to operate in the "conditioned space" not placed outside and ducted in like a conventional unit.

I would close the doors, park this next to where you are working and direct the air flow onto you. Some have 1, some 2 supply gooseneck ducts. I believe the return pulls air freely from the conditioned space.

CT

 

[Charles (in GA)]

These units are designed to cool a small area, not a whole shop. You set it up to blow air right on you, if working in one spot, or run a short flexible duct to cool the inside of a car, bus, motorhome, airplane, boat, etc while you are working steadily inside it. This is what we do with selfcontained home A/C units at work. They are mounted on a frame and casters and have a long cord and ducts and we use them to push cool air inside the fuselage of aircraft while interior work is being done.

Charles

 

[Ruthless53]

You want the evaporator intake to pull air from inside, and the condenser intake to pull from outside.

Thank you very much...got the stuff to "engineer" my own plenum and vent for it tonight. Sure not spending $130 dollars on the factory one.

 

[Ruthless53]

When I worked in a wood mill we had a trailer loads of these things. We used them in the summers as point of use coolers for operator stations. They have a condensate container you have to dump periodically while running the unit. I believe they are designed to operate in the "conditioned space" not placed outside and ducted in like a conventional unit.

I would close the doors, park this next to where you are working and direct the air flow onto you. Some have 1, some 2 supply gooseneck ducts. I believe the return pulls air freely from the conditioned space.

CT

Its "good enough" right now. Made a huge difference but "good enough" never seems to work with me. I always want to make it better. I hooked up a flexible 8 inch duct from the where the air vents out and rand it to the intake side of this Lasko blower fan so it really spreads it around the garage. I just turn the fan to the area I'm working. I'm really hoping venting the return air from the outside will allow the room to actually cool off completely instead of just blowing cold air on me as needed. We shall see.



As far as draining the container I put a hose onto the drip tube and ran it outside so it just drains straight to the yard.

 

[pseudorealityx]

What HP fan motor is that? Because that's just extra heat you're dumping into the space. 1 hp = 745 watts of heat.


And 10,000 BTU isn't going to condition a whole shop. It's less than 1 ton of capacity.

 

[Ruthless53]

What HP fan motor is that? Because that's just extra heat you're dumping into the space. 1 hp = 745 watts of heat.


And 10,000 BTU isn't going to condition a whole shop. It's less than 1 ton of capacity.

It's not really a whole shop...it's a 20x20 fully insulated garage (including the attic) with foil sheet insulation on the garage door. Now the garage door isn't completely air tight and I bet that some air leaks around the foundation but I'm not sure. 10,000 BTU's should be plenty. And as far as the fan it's a 1/16 hp....in my mind it was no difference than adding a duct fan to an hvac system. I sure don't know much about this type of stuff and have learned a lot from other responses here so thanks a lot.


Here's a pic of my redneck engendered plenum. I know that's a lot of hoses but it's in a corner that's not used and I've never once used that door so not losing much. Eventually I'm going to try ducting the air over to where I'm going to build my work benchs.

 

[Ruthless53]

When I worked in a wood mill we had a trailer loads of these things. We used them in the summers as point of use coolers for operator stations. They have a condensate container you have to dump periodically while running the unit. I believe they are designed to operate in the "conditioned space" not placed outside and ducted in like a conventional unit.

I would close the doors, park this next to where you are working and direct the air flow onto you. Some have 1, some 2 supply gooseneck ducts. I believe the return pulls air freely from the conditioned space.

CT

Another thing I noticed yesterday the water hug has ALOT less water after venting the condenser intake outside. It was completely filling up after 6ish hours before and yesterday I turned it on before I left for work just to see how it handled keeping it cool and when I got home around 5 it was not cool in there it was COLD in the garage. Enough to where I needed to turn it down. There was also the water jug was only about 1/5 full and the reduced humidity in the garage was noticeable. At this point I'd say it was a big success but we will see after a couple weeks.