A/C and dehumidification in 22x32 shop ?

[slackdaddy1]

My 22' x 32' stand alone Shop has hydronic heat with a Electro Industries 7.5KW boiler.
The shop is well insulated with 2x6 walls (r-19 batts) and roughly R-30 blown in ceiling., insulated doors, weather wrapped, etc.
The shop will actually stay cool for a few days during a change to hot weather.

I NEED de-humidification so my tools/etc do not rust.
I Want A/C to turn on only when I am occasionally out there working.

Is there any unit that does TRUE de-humidification (without cooling the air) and A/C ? Window unit or Mini split ?

I have a standard de-humidifier in there now,, I was going to strap it to the wall with a drain hose through the wall.
I also have a larger window A/C unit I got out of a house,, I would have to cut a hole in the wall.

Whats everyone's thoughts? single new unit that does it all? (if there is such a thing) or separate A/C and De-humidifier ??

 

[Showkey]

Standard dehumidifier or AC is the only answer. Obviously there are days and weeks where AC a might not be required …….so………standard dehumidifier is plan B.

Monitor the humidity levels………50% is good, above 70% starts to be a concern 80% plus is wet.

 

[PoorUB]

You can buy units that will dehumidify and AC too, but the are expensive. I would put in a minisplit and a separate dehumidifier.

 

[slackdaddy1]

Standard dehumidifier or AC is the only answer. Obviously there are days and weeks where AC a might not be required …….so………standard dehumidifier is plan B.

Monitor the humidity levels………50% is good, above 70% starts to be a concern 80% plus is wet.

I would rarely use the A/C, only those few hours a week I am in there working June-Sept (Maryland)
I would want the de-humidifier to be "active" year round (run as needed) to keep humidity below 55%

 

[Phuckin' Jim]

Even the cheapest mini splits have a "dry" mode which dehumidifies the air.
The 12,000 btu model would dry the air out without turning your shop into an ice box.
$500 or so on ebay.

 

[Showkey]

Even the cheapest mini splits have a "dry" mode which dehumidifies the air.
The 12,000 btu model would dry the air out without turning your shop into an ice box.
$500 or so on ebay.

Buying the cheapest mini on EBAY ……….sounds like a great plan…………for a future of frustration.

Buy a name brand mini………parts and service are important on minis.
Plus you need heat at low outside temp is important part of the equation.

 

[slackdaddy1]

The shop is a heated hydro slab, I don't need supplemental heat. But I do leave my slab heat around ~50 deg in winter, so "instant" supplemental heat would be a perk if I was going to paint on something,, but additional heat is not something I am figuring into the equation.

Can a Minisplit (or even a window unit) de-humidify without lowering the air temp??
How can that be done with the condenser outside ??
A de-humidifier removes moisture drawing air over the evap coils,, then re-heats the air over the condenser coils.

Another question is,, would a window unit leak warm moist air into the garage when not in use ??

 

[Showkey]

Heat is already in………so……..
Light occasional use AC Window air can be permanent mounted in a wall or in window.

Mini split would be over kill and duplication of the heat.

Run a stand alone dehumidifier as needed…….low cost, low hassle factor.
Removing humidity will some cost involved no matter the device used……it’s just the cost of comfort.

 

[Yankeefarmer]

…

Can a Minisplit (or even a window unit) de-humidify without lowering the air temp??
How can that be done with the condenser outside ??
A de-humidifier removes moisture drawing air over the evap coils,, then re-heats the air over the condenser coils.

Another question is,, would a window unit leak warm moist air into the garage when not in use ??

There’s a saying about picking your poison of choice. A mini-split dehumidifies by chilling the air. A dehumidifier dehumidifies by chilling the air, then rejecting the heat and the energy of its inefficiency back into the space. So a mini-split will chill your air somewhat, but a dehumidifier will heat your space somewhat. In those times of year where you require dehumidification, which can you better tolerate?

In our house, when it is humid and I run the mini system in “dry” mode, the humidity is effectively removed and the house is comfortable without being overly chilled. In my shop, which is well insulated with a lot of thermal mass, a mini would not be practical because the shop doesn’t warm above 70 if I don‘t open the doors and windows, so I‘m considering a dehumidifier for there. But then, I‘m looking for comfort, not chasing some ”ideal humidity level. Last summer we had more humidity than normal, and my shop averaged relative humidity in the 60-70% range. I think that would cause some folks on this forum to be concerned that their tools would rust, but it wasn’t a problem for me.

 

[PoorUB]

Even the cheapest mini splits have a "dry" mode which dehumidifies the air.
The 12,000 btu model would dry the air out without turning your shop into an ice box.
$500 or so on ebay.

They really do not work that well. what happens if the room is cold already and you want to lower the humidity? The room gets colder.

They will work if you need some cooling and want to lower humidity, but they will still cool the room.