OK, here we are in "sunny" Florida, and it has rained just about every single day since we arrived 2 weeks ago. The 2 car garage is so humid that I am seeing surface rust on bare parts/tools in just this short time. Don't want the 2 Vettes to rust before I get to use them!

So, how do I dehumidify the garage. Potential solutions are:

1. Dehumidifier, but they add heat to the area as well.

2. Air Conditioning. Don't need to actually cool the garage, just need to get the humidity down to a "normal" level.

Size of the garage is approx. 20' X 25' (500 square feet with an 8 foot ceiling). Any suggestions on either/or, and what size AC unit if that is the choice (which I think it is, due to the heat factor of the dehumidifiers). Note that I see small 5000 BTU AC window units at Sears and Home Depot for about $80-$90. A 60 pint Dehumidifier goes for $230 or so.

I will go through a program of sealing the garage up as well as possible (within limits, since this home was not built to the best standards to begin with). The 16' garage door seals on one side only, since the concrete pad was formed at an angle (.75" on the left to 1.75" on the right - great job BUBBA!).

Note that any unit I buy will only be used for the 1 year we have this rental home, since the new garage will be much larger, better sealed, and have 2 very large AC/Heating units installed.

Thanks,
Plasticman

 

I have had a problem with humidity in the summer only. My garage is 36x30 and one dehumidifier does the trick for me. When humidity is low I am able to open the windows and turn off the dehumidifier. I'm sure you will have to run yours more frequently in Fla. Good luck!!

 

I have a 2 1/2 car garage in which I have temp and humidity control. Humididy is a constant 45-50% using a dehumidifier with automatic water pump to drain. Window A/C unit (8000 btu) takes care of heat maintained at constant 70 degrees while ceiling-mount heater maintains 70 degrees in winter. My 66 BB Coupe is always happy at home - and when my Coupe is happy - I'm happy.

 

Plastic
Heres the deal their is a few ways to remove humidity. Heres the deal
when carrier invented A/C it was to remove humidity not so much to cool. but suprise it cooled. Theory was to get moisture to condense on the evaporator by being a much lower temp than the room some where around 35* to 40* F Just like outside of a nice frosty bottle of Beer. MMMMMMMM BEER!!!, drip in a pan and drain out of the space to be conditioned. A dehumidifer and A/C unit are very much the same. The dehumidfer removes BTU's from the space to lower the humidity
but it also adds BTU's (heat) to the space. As the garage gets hotter you will lose efficency of the dehumidfer. The reason it removes and adds BTU's is that the evaporator and codensor are both in the space.
A/C the condensor which job is to give of heat absorebed in the evap. by the freon is outside. WOW all that to get to here! Buy a small window unit. It will remove humidity dump it out side along with the heat of the cond. if you are not worried about cooling just set the T-stat at say 78*F. But remeber if its not running it not removeing humidity.
Now there are a couple more ways lots and lots and lots of silica like those little packets that come in the box when you buy new shoes that say's DO NOT EAT!
Or
Lots and lots and lots of heat from a furnace
but I dont think those two would be very attracive to you.
By the way I do Commecial and Industrial heating and air conditioning.

 

I echo rahzip's comments.

For the life of me, I can't understand why anybody would use a de-humidifier in the summer to remove moisture. It is nothing but an air conditioner that dumps it's waste heat back into the conditioned space.
It actually will cost more per BTU to operate a de-humidifier that it would a comparable A/C unit, and the A/C unit would cool the space!
The only correct application for a de-humidifier is for when the humidity is high, but the temperature is so mild that cooling or heating is not desired. Cooling the space will remove the moisture by the same process the the de-humidifier will, and heating the space will drop the humidity levels dramatically as well. I do not have a phsycrometric chart in front of me, but if remember correctly, a humidity of 100% at 35 degrees will drop to less than 20% if the space is heated to 70 degrees! I too am in the Commercial A/C business, and I air condition and heat my garage. It is real nice on a 102 degree day like yesterday, to be able to go out and work on the car and not sweat all over the car!
My garage is super insulated with R-25 walls and a R-58 ceiling, so it does not cost much to heat or air condition. I only have to use a 1.5 ton A/C unit to keep a 900 square foot garage quite comfortable even on a 100 degree day.

Regards, John McGraw

 

Guys,

Thanks for all the good info! AC it is.

Please advise what is the conversion of "tons" into "BTUs" (as in 1.5 ton AC unit converted into BTUs).

My 2 previous garages were: 600 sq. ft. with 12,000 BTU, and 900 sq. ft. with 14,000 BTU. The 1st one cooled down very quickly, while the 2nd was marginal but good for how I used it.

I am torn between getting the 5,000 small BTU unit or stepping up to the 10,000 unit (harder to mount in this application, and is essentially a "give away" when we leave in a year, but certainly better cooling and humidity removal).

By the way, it is raining (again) as I type!

Thanks again,
Plasticman

 

1 ton = 12,000 btu's 1.5 tons = 18,000 btu's


Regards, John McGraw

 

I cool my 3 car garage in north Florida with a 110 volt, 10,000 BTU window unit. It can't cool a hot garage, but I can turn it on in the morning and keep the garage temperature about ten to fifteen degrees below the outside temperature. Of course it lowers the humidity too. I got mine at Lowe's.

 

Send your cars to Wisconsin, we can freeze dry them.

 

Plastic,

Welcome to Florida... I see you finally made it. Be warned.. It is going to rain every day now for the next two months, usually in the afternoon. On the bright side, it usually cools things down for a comfortable evening. By the way, have you looked into the portable ACs... Sam's club has them for garages... They are basically a plug in model that sit on the floor....I don't know the sizes but I think they had two sizes when I looked into them. That way you don't have to loose the investment when you move (I assume you are in a rental until you get your home built)

I am getting my car ready for paint.... It should go into the shop at the end of the month....I am going to try to get the rest of the trim off tomorrow. I need to re-install the steering gear and column, just rebuilt them yesterday. I'd love to see your cars....

Jon
Hernando, FL

I just checked Sam's Club web site.. they have a roll around unit...10,000 BTU for $380

 

John,

Thanks for the conversion!

Kellsdad,

Looks like I will go for the 10,000 BTU unit. Thanks!

jrs 427,

Thanks for the offer, but I just left Illinois for that very same reason!

jafranke,

Will look at the Sam's Club AC units. Thanks for the suggestion. Will need to get together soon. I sent you a PM, but will send an E-Mail with my phone number/address.

And yes, it rained again this morning. But it rarely sticks around for any length of time.

Thanks again guys,
Plasticman

 

Plasticman why the move??? One problem. Last week it was about 100% humidity and 95 degrees, I pull the vette out dry and cold........ and bodda bing.... FROSTY street machine....... LOL Don't expect to go anywhere for a few minutes..

Gordon.

 

Plasticman, I live in sunny, H-O-T Texas, but I keep the garage cool with 2, 12,000 Btu Sunpentown portable air conditioners. My 3-car garage is about 36-feet by 24-feet with a 10-foot, 6-inch ceiling height. When it is 95 degees outside, and with both AC's running on low cool, I can bring the garage down to 80 degrees in an hour with a lot less humidity. I insulated the garage doors with rigid board insulation kits from Home Depot and then weatherstripped them. A hole about 6-inches in diameter in each garage door allows me to hook up the heat exhaust tube. The condensate drain tube drips to the edge of the garage door and down the driveway. They're 120-volt, 9-amp units. I purchased both on ebay for about $439 each with free shipping. Sure beats sweatin under the oldies!!! Good luck!!!