Dehumidifier vs ac

So… Florida in the summer is no fun. Summer in the garage in the summer is rough to say the least… Anyone use a dehumidifier or AC? I have a portable AC, but keep thinking a dehumidifier may be better. The portable AC definitely doesn’t “cool” by any stretch in there. We keep it for. hurricanes to cool a interior room on a generator.


Renting in Northern Virginia where the central ac doesn’t reach the top floor very well. The basement can be freezing and the upstairs hasn’t changed. We purchased a dehumidifier instead of a mobile ac unit and it’s made things much more pleasant. It was a quarter of the cost of a portable ac unit. It fills up the 35 pint in under a day.

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Wow, that is quite a bit of water removed.
A concern I would have in a garage is generally they are not well sealed, and likely there is a lot of air exchange with the outside, which would work against any cooling or de-humidifying done inside the garage.


I live up north and as is common in basement land, have always used a dehumidifier in my basements for general humidity reduction. Dehumidifiers work great for reducing excess humidity and suck an impressive amount of water out of the air. But they put out a decent amount of heat in the process. That heat actually is fine in the basement as its freezing down there when the AC is on (and cold in the winter) but, that heat could be quite problematic in a Pain Cave. I’d defer to anyone who has actual experience but be aware it could end up being a net minus if you lower the humidity a bit but make your pain cave hotter.

FWIW - AC and dehumidifiers work with basically the same process but an AC unit is set up to dump the heat outside. In fact, AC was first invented to control humidity and the cooling was just a bonus.


Exactly. As @toyman said, a garage is just not insulated enough. You’ll be wasting electricity for little benefit. Just buy a bunch of fans or train indoors if you can’t handle the heat/humidity outdoors.
I had a similar idea for my garage but it just doesn’t work in practice.


I’m also a south Floridian and I use a dehumidifier, the portable a/c is a pain in the :peach: to get set up properly in my garage. I try to be on the bike by 7am and the latest I’ll stay is 10:30-11am. It gets too hot as you know, also using cold/ frozen water bottles to sip helps during summer.
I have a huge fan that is almost on top of me for cooling. 30”fan with a cut piece of pvc pipe to angle it. Took me a while to figure the best angle but it works! It’s one of these bad boys from Home Depot for $275……make sure you get plenty of salt and electrolytes afterwards!


I’m going to disagree with some comments above: I have a big window unit in my garage, and it cools the place down pretty fast. Ambient temps have been 80’s and 90’s here lately. Very easy to get it cooler and dryer than the much more insulated basement where we have a dehumidifier running 24x7, and I can start it up with fans when I start my workout and it’s really fine.

Advantage of a properly sized AC is that it cools and dehumidifies. But, you need to make sure it’s appropriately sized or oversized for the space it’s in though, and those portable units aren’t as efficient as window units and definitely not as efficient as a mini-split.

For the record - it gets run while I’m in there working out or working on something, not all the time.

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That makes sense. Ive been thinking about framing out a area for the trainer, next to a window that we could actually insulate and run a small AC. We’ll see… That’s a winter project.

Was wondering if some of you with experience with dehumidifiers can weigh in on a question…my wife has MS and humidity just wreaks havoc with her. Makes all her symptoms worse and walking is a challenge on a good day. Humid days just kill her…

We keep the house very cool to help her as much as possible (I often have to wear a sweatshirt inside during the summer), but even then the humidity can be tough. I am considering putting a portable dehumidifier downstairs as well if that would suck more of the humidity out of the air……

Also, how noisy are they?


Only two advantages to a dehumidifier:
you can leave it running where if you left the AC running as long you would get too cold
You can run a smaller dehumidifier in that portable ac units tend to reduce the insulation of the space a bit and so seem to not cool very well.

As STP said, the only difference is where the heat is dumped. But remember the unit generates heat when running so with AC heat from the space and unit gets dumped outside vs all the heat going inside.

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This was my first thought. My basement flooded 2 weeks ago so I’ve been running a borrowed dehumidifier down there since. It’s noticeable hot in the basement when I open the door and the dehumidifier running. Previously it was kind of refreshing to walk down there on a hot day and now a few times it feels warmer in the basement than outside.

I use a small single room type portable ac unit in my shop, 30*40 with 16ft ceilings so way undersized (but was free). Makes a noticeable difference in comfort on 80+ degree days.

I’d definitely go with either a portable ac or a window unit for use with the trainer. Mini split will be more up front but more efficient so hopefully cheaper to run long term. And might even have option for timers or app control to pre condition the space.

Florida is tough. Evaporative coolers don’t work because the humidity is too high. Fans just blow humid air around. Best bet is a regular air conditioner unit (through the wall or window, or mini-split) blowing right on you, but it’s going to be expensive to buy and run.

(Portable AC units just aren’t very good)

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Very true

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I live in Japan, and I reckon the climate is very similar to Florida: very hot and humid. (The weather app shows 100 % today …) We have a dehumidifier in our bedroom and an AC in our living room, which is also where I train. No way I could survive with a humidifier and fans. Even with the AC on, I sweat buckets in the summer (I have to drink about 1,3 l = 2 large bottles per hour to give you an idea).

With ACs it also depends on whether you have central AC or small units meant for individual rooms — we have the latter. The issue of insulation that others have mentioned is important, though: many homes in the “southern 2/3” of Japan lack insulation, so once you switch off your AC, usually the temperature rises very quickly. Despite that, I think an AC is your best bet.

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