Florida garage workspace cooling experiments...

[gfmucci]

Note "workspace" as in "workbench" area, and not the entire garage.

I don't want to spend $2,000 or more on a mini-split and not sure there's even a space outside that I could put the unit. The garage is 15 by 25' with 8' ceiling, no windows, attached - living space on two sides- neighbors garage on the thrid side, insulated garage door.

So in Florida, I went against conventional wisdom and am trying out the "swamp cooler" route to cool my work area. The "cooler" is located within a couple feet from my position at the bench.

While this "evaporative cooling" device isn't real effective above 50% humidity, it does provide 8 to 10 degrees lower temps coming out of it than the 90 degree ambient temp of the garage.

In an effort to bring the 60% average humidity down to below 50%, I installed a dehumidifier. Short story: It made the garage a lot hotter overall when trying to achieve 40% and a couple degrees hotter when set at 50%.

My next step is to install an unducted forced air ventilator (350 cfm) in the ceiling to vent into the attic over the garage. The roof has ridge and soffit vents, so the hot air should have no problem getting out.

By next week I should have the ventilator installed and will report back. I'll let you know when the cost of my experiments approach the cost of a mini split.

 

[59 wagon man]

the answer my friend is blowing in the wind. never gonna stop you from sweating but a bunch of fans is the best you will do with opening the garage door and little to help in the flow of air. i live in south florida and luckily had a friend who did a/c install as a gift

 

[gfmucci]

the answer my friend is blowing in the wind. never gonna stop you from sweating but a bunch of fans is the best you will do with opening the garage door and little to help in the flow of air.

Where are Peter Paul and Mary when you need them?

I have a big ceiling mounted utility fan and a little one at my bench. As I mentioned, the swamp cooler blows air on me 5 to 10 degrees cooler than the temp coming out of the other fans. I expect the ceiling ventilator blower to help out some by extracting hot air from the room. I'm hopeful for at least a 2 degree reduction from that.

I'm not much into constraining myself with an attitude of "that's the best you can do."

I had an 18,000 btu Mitsubishi mini split in a garage in The Villages a few years back. While I loved that system for cooling the whole garage, all I want to do now is cool my immediate work bench area a few degrees a few hours a day. I'm not going to spend $2,000 to $5,000 to do that. Or even $1,000.

 

[ticklechicken]

I'm not going to spend $2,000 to $5,000 to do that.

I wouldn't either. Buy one for much cheaper.

 

[gfmucci]

I wouldn't either. Buy one for much cheaper.

Where will you be coming from? I'm in Ocala. I'll give you directions on how to get here. I'll be your installation helper.

You'll crawl into the 110 degree attic and run the 50' of line set, run and install the new electrical 50' to the where the compressor unit sits on a new pad and the new electrical where the air handler goes. Oh, and since the pre-charge won't work with the extended line set, you'll buy the extra freon and charge 'er up and test for me. And I'll probably need 18,000 BTUs. THANKS!

In the meantime I'll get the approval from the HOA and order the system, the extended line set, extra freon, the pad and electrical components, and oh yes, almost forgot, the permits.

Yup, $2,000 minimum.

 

[ticklechicken]

Another option is to add a window unit. I did this is a previous house of mine where the garage had no windows and there were HOA restrictions. Sounds just like what you're dealing with. I came up with an installation that didn't cut any holes in the wall and resulted in the system being invisible from outside. The whole system only cost around $400 and avoided all the headaches you mentioned. I wrote up an article fully detailing the install.

 

[Showkey]

Yah......when you live a swamp........a swamp cooler is ( was) not going to work.

 

[gfmucci]

Another option is to add a window unit.

There are no windows and no exterior walls.

 

[gfmucci]

Yah......when you live a swamp........a swamp cooler is ( was) not going to work.

No swamp here. Lots of nice mature Oak trees. 90 foot elevation. Rolling hills.

The swamp cooler already "works" o wise, unhelpful one. It sends out air averaging 8 degrees cooler than ambient. I'm just experimenting ways to reduce the temp another notch or two.

 

[Rusty Fords]

I understand wanting to get some cooler air blowing on you. If you currently have 60% humidity (If I read that correctly) you may be dropping temp but adding more humidity with a swamp cooler. More moisture to tools and parts? I wouldn't recommend. I know it will not remove any heat energy from the garage but you could just stick a window unit on a stand and have that blow on you while you are working. It will remove some of the humidity and blow cooler air on you normally around 20 degrees cooler. I'm not sure what a window unit would run you down there. Good luck.

 

[gfmucci]

I understand wanting to get some cooler air blowing on you. If you currently have 60% humidity (If I read that correctly) you may be dropping temp but adding more humidity with a swamp cooler. More moisture to tools and parts? I wouldn't recommend. I know it will not remove any heat energy from the garage but you could just stick a window unit on a stand and have that blow on you while you are working. It will remove some of the humidity and blow cooler air on you normally around 20 degrees cooler. I'm not sure what a window unit would run you down there. Good luck.

I addressed the humidity problem in my OP as follows:

"In an effort to bring the 60% average humidity down to below 50%, I installed a dehumidifier. Short story: It made the garage a lot hotter overall when trying to achieve 40% and a couple degrees hotter when set at 50%."

The dehumidifier is mounted on a shelf up near the ceiling over a utility sink for drainage about 15' away from my work area. I am very short of floor space and mounting space for a small ac (around $170, Amazon - a similar price of the dehumidifier). I would also still have the condensate and heat problem with the ac if it was located near my work station. My particular swamp cooler is one of those 40" tall skinny fan devices with a 1 sq ft footprint.

If I mounted a window ac unit up where the dehumidifier is, I wonder if the heat output out the back would offset its cooling output out the front - and whether any cooling effect would reach me from 15' away. You're right, it would act as a dehumidifier. That option may be an interesting Plan C if the next step in my cooling experiment (the ceiling mounted exhaust fan) doesn't help.

In fact, since the exhaust fan will be mounted right behind me, a good plan C or D would be to mount that little AC unit on the ceiling near the exhaust fan so the rear hot air exhaust faces the exhaust fan and is [mostly] sucked out. I would need a 15' condensate line to drain into the the utility sink. It would have to be suspended no higher than the bottom of the ac unit for effective gravity feed.

Interesting food for thought. I can only imagine what the realtors would think when they try to sell this place after I croak.

 

[Joemctag]

Any way you can have a small window a.c. on a movable cart and have it exhaust through a removable panel in your garage door? It’d take some doing but then you’d have a really nice setup, I’d think.

 

[pbon]

There is no way I would not put AC in a garage in FL if I was going to be doing more than minimal work in it. I’d look into a DIY $2k minisplit. In NH, I put an 18k window/wall unit through the wall. I am not yet at the house in FL enough to get to that project or expense but it is on the list.

 

[gfmucci]

Photos of existing swamp cooler and dehumidifier...

Swamp cooler next to work bench: https://flic.kr/p/2jmdedP

Dehumidifier above utility sink: https://flic.kr/p/2jmc3Gu

Perspective of workbench, cooler, and dehumidier:https://flic.kr/p/2jmdbmW

 

[gfmucci]

Any way you can have a small window a.c. on a movable cart and have it exhaust through a removable panel in your garage door? It’d take some doing but then you’d have a really nice setup, I’d think.

This is an exercise in tradeoffs and compromises:

The factors are:

Cost: My self imposed limit is $400; shooting at dawn if much more.

Convenience: Don't want to take a lot of setup/breakdown time everytime I go out to the workbench for a couple hours. Fresh ice for the swampy takes 1 minute. It's not a big enough garage to roll stuff around in it unless I remove the SUV each time I set up.

Effectiveness: I'm within a few degrees of an acceptable comfort level. Low 80s/high 70's is a comfortable temp with <50% humidity and a fan/swampy blowing on me.

Roaming around the garage working on stuff away from my bench is a different matter. Cooling in that scenario is not within my intended scope of services. Except when I can direct my ceiling mounted 18" MaxAir fan to my work spot, non-workbench activities will continue to be sweat-inducing.

 

[ticklechicken]

There are no windows and no exterior walls.

I'm not sure where the confusion is. With the installation method I designed, you don't need windows or exterior walls.

 

[59 wagon man]

i believe they have portable cooling units with wheels and a flex hose to exhaust warm air maybe that might help blowing right at you and it doesn't take much floor space

 

[gfmucci]

The whole system only cost around $400 and avoided all the headaches you mentioned. I wrote up an article fully detailing the install.

Sorry, I missed your "no windows" part. Could you send or link me to the article you wrote detailing the install?

 

[Showkey]

No swamp here. Lots of nice mature Oak trees. 90 foot elevation. Rolling hills.

The swamp cooler already "works" o wise, unhelpful one. It sends out air averaging 8 degrees cooler than ambient. I'm just experimenting ways to reduce the temp another notch or two.

Swamp like:

The answer to this question is yes! With Florida being surrounded by the warm Gulf of Mexico and Atlantic Ocean, and with South Florida being a nearly tropical climate, it is definitely the most humid state in the U.S. Attached is a map of annual average dew point temperatures across the coterminous U.S. The map shows that north Florida has dew point temperature averages of 55 to 60 while south Florida averages greater than 60.

So dropping the temp slightly and raising the humidity levels is a counter productive.

Unfortunately, evaporative air coolers don't work everywhere. Swamp like climate , for instance, are lousy places for swamp coolers. It's not entirely clear where they got the nickname, but it probably refers to the humidity they add to the air or the swampy smell that can develop when they aren't cleaned often enough. In order to work, they need a hot, dry climate. In the U.S., swamp coolers work only well in the arid southwest.

HINT: If your tee shirt does not dry quickly ..........the swamp cooler is an epic fail.

 

[Joemctag]

I would like to know about your install.

 

[pbon]

Cut through the wall. Look for a used 240V 18-24k window/wall unit for $300. A 12k might do it if you run it 24/7 on its thermostat - it will cycle so it is not using power all the time. If you let your walls and floors and ceiling and everything in your garage heat up to 90+ then of course you need much more power to cool it down quickly so you can work comfortably in the area.

 

[gfmucci]

Swamp like:
The map shows that north Florida has dew point temperature averages of 55 to 60 while south Florida averages greater than 60.

I currently live in the north central part of the state. The humidity is significantly less in the interior than along the coast which most of the "humidity notoriety" comes from.

In spite of the humidity outside ranging 70% day/99% at night/100% when raining in the summer (much lower humidity in the winter) the humidity in the garage is maintained ~50%. That is an ideal level. This is achieved in part due to the garage being surrounded on three sides by enclosed space (two sides being AC'd space) and in part from the dehumidifier I installed to give a quick humidity reduction after the garage door is open for a short time. After a half hour of the garage door being down, the dehumidifier kicks off for at least several hours maintaining the 50% humidity.

BTW, I've lived in Florida for >60 years.

The more definitive results of my experiments will be known after I install the exhaust fan into the ceiling by next week.

 

[gfmucci]

Cut through the wall. Look for a used 240V 18-24k window/wall unit for $300. A 12k might do it if you run it 24/7 on its thermostat - it will cycle so it is not using power all the time. If you let your walls and floors and ceiling and everything in your garage heat up to 90+ then of course you need much more power to cool it down quickly so you can work comfortably in the area.

"Cut through the wall?" One wall leads to the neighbor's garage, another wall leads to my kitchen, the third remaining wall leads to my living room. I'm out of walls. Through the wall units are not allowed in my HOA.

I picture a couple of scenarios:

Neighbor: "Why is it so much hotter in my garage? And what's that metal box in my wall for?
The neighbor is old is gone for months at a time; there is a chance he wouldn't notice.

Wife: "Why is it so much hotter in my living room; what is that racket? And why are you still living here?"

Theoretically, I could mount a window unit on a stand or shelf as others have suggested and port the exhaust/heat out the front of the house through one of the short, 18" wide walls on the side of the garage door. From the outside it would look like a large dryer vent (would still require HOA approval which is not assured since its the front of the house). And there is a good possibility the perimeter wall around the garage door is poured concrete with rebar. The ducting leading from the AC to the outside could be mounted along the top of the wall at the ceiling so as to not take up precious, limited wall space.

Here is an article from another web site that discusses another option for venting a room AC:

Venting Through a Drop-Ceiling
This ventilation technique involves adding or reconfiguring a drop or panel ceiling into a ventilation zone.

This method is used quite often in computer server rooms because these areas usually aren’t equipped with windows, meaning that alternative sources of ventilation need to be implemented.

To vent your portable air conditioner through a drop-ceiling, just cut a hole in a ceiling panel that can accommodate the exhaust hose.

Add some sealant around the connection joint, and you’re done.

Instead of through a "drop ceiling", venting could go through the regular ceiling into the attic the same way my ventilator fan goes through.

There are cautions about venting an AC into an attic though as described HERE. I wonder if this caution is more applicable to cooler climates where attics are cooler and damper. In my neck of the woods, attics are hotter than hell and therefore likely low humidity - another factor to verify. I can't imagine that the air going INTO the attic from my 50% humidity garage would be higher than what is already in the attic, which is basically outside, unconditioned air.

That could be "plan D" after some additional fact finding.

 

[59 wagon man]

with the exhaust hose from the rolling portable a/c you might be able to use something similar to what a mechanics shop up north uses when they put the exhaust hose on a car and run it thru the rollup door to keep the door closed

 

[nadogail]

Rather than cool the garage, can you reduce the heat gain with an insulated garage door?

 

[gfmucci]

Rather than cool the garage, can you reduce the heat gain with an insulated garage door?

The garage door is insulated, as is the garage ceiling.

 

[Falcon67]

There's a reason nobody uses swamp coolers in places like Houston or NOLA, and why they work well in western NM and Arizona. Also, my experience with portable AC units is that the are half *** at best. You can either cut a hole in a wall and mount a conventional AC unit through it, ro save up for a mini type unit.

The only way to make a swap cooler work in 50%+ RH is to start putting ice in the bottom. Been there done that. For a small swamper a 10 lb bag works for a while. And make sure the pads are fresh. Once they get worn or "dingy" they lose a lot of effective cooling.

 

[gfmucci]

There's a reason nobody uses swamp coolers in places like Houston or NOLA, and why they work well in western NM and Arizona. Also, my experience with portable AC units is that they are half *** at best. You can either cut a hole in a wall and mount a conventional AC unit through it, or save up for a mini type unit.

The only way to make a swap cooler work in 50%+ RH is to start putting ice in the bottom. Been there done that. For a small swamper a 10 lb bag works for a while. And make sure the pads are fresh. Once they get worn or "dingy" they lose a lot of effective cooling.

You are absolutely correct about the limitations of swampers and the need for ice. That is exactly what I do. I'm out at my bench only about an hour at a time anyway and that is about as long as the ice packs last - the packs I use being about 1/10th the volume of a "bag" of ice. I got an extra set of packs to extend my time if needed. About 3 or 4 of these fit at a time in my small swampy - obviously my unit is a lot smaller capacity than your "small" swampy:
https://www.amazon.com/gp/product/B01HBN17CS/?tag=atomicindus08-20

With ice, I get about 8 to 10 degrees cooler air than ambient blowing on me. I expect the ceiling exhaust fan to cool down the ambient garage temp another couple of degrees - a bit more if I leave the door to the house open a bit.

This is the swamper I'm using, raised up off the ground for greater effectiveness: https://flic.kr/p/2jmdedP

I've seen some really neat looking DIY ice chest swampies on YouTube. Those show to be a lot more effective than the one I bought. I would have made my own if I knew about them.

Interesting: I posted a similar garage cooling proposal on a DIY website forum. Most of the guys over there act as if they are a bunch of **** bureaucratic building inspectors - Dr. Doom on steroids. I appreciate the open-mindedness and ideas presented by you guys. Thanks.