Climate Control In A Southern Shop

[John Hays]

Anyone have a good experience with portable AC units and dehumidifiers?

I'm looking for a solid solution to keep my newly built shop cool and dry as much as possible, because the heat and humidity in the summer down here in GA is insane. Unfortunately, the circumstances limit me to alternative devices to accomplish this goal. Here are just a few examples:

#1. I live in a flood zone, so I had to build 'break-away' walls (which only support 20 lbs per sqft). This means that a typical wall unit is too heavy and also against local code.

#2. My electrician says that the sub panel is already maxed out, so there's no room for a ductless system.

#3. The wife said that building the shop was expensive enough, so she informed me to find a cheaper way around the problem (and who am I to argue with that? LOL).

So my brilliant plan is to use a portable AC unit to cool the 600 sqft. area and a dehumidifier to keep the rust off of the tools. I'm looking at this AC unit:
http://www.amazon.com/Soleus-Air-LX-...0913150&sr=1-3

and this dehumidifier:
http://www.amazon.com/Soleus-Air-DP1...5822216&sr=1-3

The problem is, the reviews for portable AC units are all over the map and I'd rather not purchase a piece of junk if I can help it, so hopefully someone here is using something similar and can offer an opinion.

Also, is there a reliable brand for a digital hygrometer? Again, reviews are all over the map.

And lastly, is this just an idiotic idea or will this actually work?

[Bob Betker]

John: I'm hoping you get some answers because this is the route I plan to take for the short term with my workshop. I live in Northern Virginia and can only imagine the humidity you get down in Georgia. I can't answer your questions about the particular units you have mentioned but I experience with dehumidifiers used in our basement. We had a Whirlpool unit that I picked up from Sears about 5 years ago and while it does a good job it is very noisy., I mean really noisy; I can hear it upstairs when it is running. About a year and a half ago, I purchased a Frigidaire unit from Lowe's when our basement flooded and we needed more dehumidifying capacity. The Frigidaire unit is very quiet and is easy to operate. Removing the tank is a pain but I hooked up a hose to the drain system and rarely have to remove the tank, only once or twice a year to rinse with a bleach solution. I would look at purchasing another Frigidaire unit based on my experience. What I believe is that Whirlpool or Frigidaire or the other major manufacturers don't actually make the units, they are subbed up to another company, probably Chinese, and then the US corporation slaps on their name plate and sells it in the US. So you really aren't sure of the quality. Since returning a defective or substandard unit to Amazon.com can be a pain, I'd look at buying a unit from a local retailer (Sears, Best Buy, etc.) with a good return policy and give it a 30 day trial. If there any problems, take the unit back.
Good luck, Bob

[John Lifer]

Buy a 10K or so window unit. Build you a frame to support so you won't put weight on your walls. (2x's or welded) Forget the portable. Had a portable, was ok, but realize that you have to get rid of the moisture generated. In GA (same as MS) that is a gallon or three a day. This is pretty good problem to solve. The other problem with the portable is though the unit is 12k btu, you will lose a LOT of heat thru the 4 or 6" pipe that direct the heat outside. And it stays in the shop. So reality is you might have 8-10K btu actual cooling. (my guess and you can place close to wall and make that loss less, but not zero like a window unit) Sorry, I don't think I'd buy another one. Your #2 is irrelevant as you have to power this unit or a window unit. You can use extension on either or neither. #3 window unit is cheaper, you can find closeout, used, or new cheaper than the portable. And in all honesty, window unit will last longer.

[Van Huskey]

A window unit supported how ever you have to do it will be a FAR better solution. Cheaper, more effecient and out of the way.

[David Kumm]

The only half way efficient dehumidifieirs are the commercial"Phoenix" type and even used they are about the same as a used ductless split system. If you watch they come up fairly often in the $500-700 range. Much better than the window variety and most run on a 20 amp circuit-220. Dave

[ian maybury]

I'm not familiar with what's available in the US guys, but got suckered into buying a €250 domestic unit by taking casual mentions on forums of using domestic dehumidifiers for workshop conditioning and wood drying at face value. Which led to my taking a closer look at what's needed.

There may be some difference in the typical units sold here versus those in the US (where they are much more common usage), but the core issue I ran into is that the domestic (damp removal) variety do not control air moisture content to the % RH you need ( there is no option to set it to that) - they instead use some sort of 'smart' routine that doesn't drop a space much below about 65% RH.

Chances are the type of refrigerant is such that they anyway can't chill the air low enough to get to the roughly 43 deg F dew point that corresponds to the 45% RH at 65 deg F that corresponds to about 8% wood moisture content. (EMC) They in reality remove their listed litres/hr or whatever of water in only ideal conditions, and most of the time do maybe only 1/3 of that.

I never finished the search (budget!), but had more or less concluded that I needed a much larger (and more expensive) industrial unit capable of being pre-set to the required %RH....

ian

[Jim Andrew]

Wish someone would explain the "break away walls". Is gvmt requiring buildings that fall apart in case of flood?

[Van Huskey]

Wish someone would explain the "break away walls". Is gvmt requiring buildings that fall apart in case of flood?

Not as crazy as it sounds, it prevents damage to upper floors. The idea being you are on the second floor and the bottom floor opens up and so the second floor stays intact, without them it would take down the entire structure.

http://www.fema.gov/plan/prevent/flo...away_wall.shtm

[John Hays]

Thanks for the input everyone, I really appreciate it. I kind of figured that the general consensus was going to be in favor of a wall unit, but I'm just not ready to cut a huge hole in the wall for it yet.

I think I am going to try my solution, just to see if it works. The reasons for this decision are:

#1. Our house sits about 1/2 mile from the coastline and the garage (now my shop) doesn't get much direct sunlight as it is.

#2. The sea breezes alone seemed to keep the temperature in the garage fairly cool during the summer last year (about 5-10 degrees lower than the actual temp outside) when the walls were just slats.

#3. There are no windows or doors for cool air to escape through (or heat to enter), except when the garage door is opened, of course.

#4. The walls and garage door are very well insulated.

#5. In all honesty, I'm not even sure the 600 sqft space needs to be cooled, due to the concrete floor, insulated walls, lack of windows and minimal sun exposure... but I'm sure it would come in handy on 98+ degree days.

#6. The main problem seems to be the humidity. If I can keep that down to an acceptable level, then everything should be okay.

Anyhoo, I still need to build covers for the flood vents and buy the units, so give me about a month and I'll report back here with the results... unless someone can sway me over to an indisputable system.

Btw, I'm still looking for an accurate and reliable digital hygrometer if anyone has any leads.

[Ray Newman]

"I'm still looking for an accurate and reliable digital hygrometer if anyone has any leads."
--John H.

Contact a few of the local HVAC contractors for a reccommendation???

[Jim Foster]

I'm in MA and we also get lots of humidity in the summer, high temps also. My shop is above a garage. I bought several $5.00 digital temp/humidity displays from Home Depot and have a dehumidifier in the garage and a wall unit AC in my shop above. The temperature does not bother me too much unless it's in the 80's, but the humidity makes RUST and the shop unbearable. So far the magic number is around 53%. Whenever the humidity gets above 50% I turn on the dehumidifier and the AC unit to keep the humidity under 51%-53%. I have not had any rust issues over the last two years. It's a manual system, so it's a bit of a risk during summer months, and I have to remember to turn things off at night and check in the AM. Over time I'd like to get a rig set up that turns on and off via the humidity reading not temperature like a regular thermostat.

It's cheap (I already had the AC unit and dehumidifier) and its been manageable so far. If I was traveling a lot, it would be a challenge.

[Brian Loran]

I bought one of these for my garage/shop last summer when it was 108F+ for like 3 months straight. I'm in Dallas so not as humid here. It works pretty good. I was able to cool my garage down to 85F when it was well over 100 outside. Probably could have gotten it cooler but I didn't push it. 85F felt great compared to what it was without it. Plus I could aim it toward where I was working (usually at my bench) and was very comfortable. Costs a lot more than a window unit but my garage does not have any windows or doors other than the over head so..... I also insulated my aluminum overhead door.

DeLonghi PAC-A130HPE Pinguino 13,000 BTU Portable Air Conditioner

[Steven Green]

I've got one as well. Works well in the winter but I wasn't impressed with it in the summer. Just didn't have the btu's to cool the space effectively. Rust on the tools really slowed down though. I'm building a new shop in the next couple weeks and I'm gonna put baseboard heat in for the winter and a large wall unit for the summer. I live in Illinois and summer is brutal.
Good luck

[Michael W. Clark]

I would stay away from evaporative cooling in the south or high humidity areas. Have you considered a PTAC (Packaged Terminal Air Conditioner) unit that is floor mounted? I think one of the editors of Popular Woodworking has one in his shop in Tennessee. These are similar to the hotel room units. You are not going to get much done without additional electrical unless you can install doors/windows to create a natural draft. In south GA, sometimes that doesn't work. Albany ("Albiny") was one of the hottest, most humid, and had one of the highest concentration of gnats that I've been. Refrigerated type AC units reduce the humidity.

[Neil Brooks]

My $10-$20 min/max thermometer hygrometer meters, bought at the BORG, have matched my HVAC guy's $350-ish Fluke to within a few tenths of a degree/% RH.

They were this kind.

I have two. Couldn't be more satisfied with them, and ... get battery life that seems like it's longer than MY life