Portable AC Unit For Basement

D107

I have a 500 sq ft basement out of which only 350 needs to be cooled. Have had a dehumidifier for years but builds up great heat in summer and drains into slop sink. (humid NY area). Is there a portable AC unit that will work here without a dump bucket? I don't want to install a window unit or mini-split just something simple. The Emerson Quiet Kool SMART Wi-Fi and Voice 300-Sq. Ft Portable Air Conditioner claims 'auto evaporation' but I can't imagine how that would work. Usually the ones I've seen being use in stores--a lot in Europe--have a little hose coming out the door for the condensed water and hot air. Recommendations? I would keep tempt at 78º--would a 5000btu unit work so it dehumidifies as it cools?

mattmia2

They reevaporate the condensate and blow it outside as vapor with the condenser airflow. Most window air conditioners do that as well if they are installed and working correctly.

There used to be some with a water cooled condenser but those have been mostly outlawed due to their enormous water consumption.

Jamie Hall

There is an amazing variety of portable air conditioners out there... try Home Depot or Lowe's or even Amazon. They all, of course, require access to outside air to which to dump the heat -- and that's where the condensate goes, as @mattmia2 said.

D107

Below is current dehumidifer setup. If I replaced that with a portable AC, had someone drill a 3-inch? hole through the brick for the exhaust--(air and water together?) would that work? Of course uninhabited boiler room is not best efficient place to air condition but best access. Then I probably have to run a hose extension away from foundation. The current heat generated by dehumidifier is just too much--and in dead of humid summer sometimes screws up my boiler draft.

If the AC is small enough I could put it up high enough so that it would drain by gravity and not have to pump it out. Outside ground level is at a little less than middle of the dehumidifier. Maybe water could go in slop sink and heat could be blown outside?

Jamie Hall

Portable air conditioners -- which are about the size of that dehumidifier -- require both an outside air intake and an outside air exhaust. Some of them do have arrangements so that both intake and exhaust can go through the same opening. Most don't. They do not require a separate condensate provision. They are intended to be installed with the intake and exhaust in a handy window, but you certainly could drill holes through the foundation wall.

D107

@Jamie Thanks. So the hot exhaust air carries within it the excess humidity. So if I specified a small enough unit that would dehumidify as fast as it cooled I'd be ok? We have awning windows down there and I can't figure out how that would work without making holes in the glass--also brings up security issues. Going mini-split raises price I'm sure, perhaps efficiency. Hmm, we do have a small half bath at the top of the basement stairs with a small double hung window that might fit a small AC that might handle the basement as well.

Canucker

There are single pipe exhaust for portable ac but the rule of thumb is to derate the capacity by half to determine what it can cool. They de-pressurize the room they're in but they're effective if you size them right

kflory

D107 said:

Recommendations? I would keep tempt at 78º--would a 5000btu unit work so it dehumidifies as it cools?

Portable A/Cs take up a bunch of room and are significantly less efficient than window units and mini-splits. If your living area isn't conditioned, you could get a mini-split that has a larger feed for the living space and a smaller feed for the basement. Mr. Cool makes DIY mini-splits if you are feeling up to a little handywork. ForestAir also makes portable mini-splits, but they require the ability to pass the back of the unit through and seal around it (like a sliding door would) so that may not work for your basement.

https://mrcool.com/diy-3rd-generation-e-star/

https://www.forestair.ca/en/serie-mini-anglais

The portable A/C is the simplest option though. A through-wall A/C would be a better option that keeps space in the basement available without going to the expense of a mini-split.

ChrisJ

I'm not sure if it was mentioned or not but usually replacing a dehumidifier with an A\C isn't an option because the A\C will cool the space and in a basement will usually result in overcooling and just shutting off. It'll run, but often not enough for good dehumidification.

Both together on the other hand would work nicely.

In a space that requires little cooling some sort of reheat is necessary.

pecmsg

You need a Heat Pump Mini split that can supply heat 3/4 of the year.

D107

@pecmsg Thanks. Problem is basement is already heated by hot water boiler; too bad can't get attic 3-ton AC ducted and return registered to basement.
Good point @ChrisJ I'm thinking maybe bring the dehumidifier into main basement room--more efficient drying main room air than the boiler room which is further away. And then using a nice size fan to cool--heat is not terrible in basement. Will just have to empty bucket once or twice a day.
@Canucker I'm a little confused on one thing: if you're supposed to derate by half the square feet cooling rating to size unit, that would seem to go against the other advice that an oversized AC will cool things up quickly without dehumidifying. I figured for a basement with 350 out of 500 sq feet habitable space (omit boiler room), if I got the smallest AC possible, the cooling and dehumidification would be more in balance.

Wall AC unit does seem doable if I want to chop out that big a hole in my brick foundation. First experiment for me is to move Dehumidifier into basement room and use fan. I keep it on a timer on/off on 30 minute cycles....

pecmsg

Your not running the heat. That’s why a heat pump temperate the air. 

mattmia2

You could get a condensate pump and dump the hose outlet of the dehumidifier in to it and pump it to a sink or outside.

Canucker

@D107 I'm comparing it to a typical window unit. If the single pipe portable is rated for 8000 btu, it will perform like a 4000 btu window unit.

Alan (California Radiant) Forbes

I'm interested in one of these as well for a very small wine cellar; 5' x 8'. The cellar is under my front stairs, on the north side of the house.

I want to keep the room below 60F, but don't want to spend a lot of money on electricity. Any suggestions?

ChrisJ

Alan (California Radiant) Forbes said:

I'm interested in one of these as well for a very small wine cellar; 5' x 8'. The cellar is under my front stairs, on the north side of the house.

I want to keep the room below 60F, but don't want to spend a lot of money on electricity. Any suggestions?

Move further North?

mattmia2

I was thinking dig the hole deep enough that it stays cool on its own...

Alan (California Radiant) Forbes

These are all practical suggestions. Thank you! |: (

ChrisJ

Alan (California Radiant) Forbes said:

These are all practical suggestions. Thank you! |: (

To be fair, I don't think anyone wants to spend a lot on electric for air conditioning. But it costs what it costs. I think the cheapest way when it comes to electric is a high seer minisplit.

mattmia2

I think this is case where the alternatives to spending sort of a lot on energy will be far more expensive.

ratio

@Alan (California Radiant) Forbes, I rehabbed an old wine room unit a while back, it was literally nothing more than a little air handler coupled with a walk-in style condenser with an internal crankcase pressure control valve, CRO-4 IIRC. Used System 350 controls for dehum & cooling, it didn't have the heating accessory kit.

If it were me, I'd download an IOM for some little commercially available system & see if I couldn't duplicate it with similar parts from the local supple house. But I am know to be a little eccentric in what I consider fun…