HVAC In The Shop

[RayH]

I plan to add heat and air in the shop/garage. The heating contractor has proposed using one of those under-the-window-and-through-the-wall units like you see in most motels. They take up a bit of wall space (42"w x 16"h), but my motel experience suggests they can move more air with less noise than a standard window unit plugged in a hole in the wall.

Does anyone have any personal experience with these units in a shop? Any recommendations/cautions/etc.?

Thanks,
Ray

[Douglas Robinson]

The last FWW Tools and Shop issue featured a shop that used a unit like that in a 20 x 20 shop. Looked like a good choice.

[toolferone]

I have a good friend in Indianapolis who uses one in his 20 x 30 shop and loves it. He uses it full time all year.

[scsmith42]

Don Patterson (Touchwood on NCWoodworker.net), has one of these units in his shop and told me that he's been very pleased with it.

Scott

[RandyJ]

I have a GE Zoneline (heat & AC) unit in my 16x30 shop. I've had it for almost 11 years and have been completely satisfied with it. One nice feature is called FREEZE SENTINEL. Even if the unit is turned OFF, when the temp goes below 40, it automatically comes on. This can be disabled if you don't want it....
I know Ferguson's in Raleigh sells them(not where I got mine), but you may find better deals elsewhere.
Good luck,

[Touchwood]

I've had a GE Zoneline through-the wall unit in my shop for 18 years and the only trouble I've had required me to replace a buzzing power relay and a fan bearing...easy job both.

My unit is Model AZC906DAV1, but they've changed model numbers since I bought it. The equivalent today is in the "Deluxe 3800 series" and I'm sure it's more efficient, but mine delivers 14000 BTU, runs on 220V., pulling 8.5 Amps. These units are basically heat-pumps so you get cooling in summer, heat in winter and I can hold the shop at 70 +or-a degree or two year round. The heat-pump handles outside temps down to about 25 degrees..it cuts in the heat strips after that. The reverse pump air conditioning is great.

My shop is about 24 X 36 with a 9 ft. ceiling and I know it's well insulated because I built it myself. You need to put in some kind of air circulation or it will cycle on and off and overshoot/undershoot temp settings. I put in two 40" fans rotating in the updraft direction and that solved the problem.

The GE units are extremely quiet and very reliable (can you tell I used to work for GE). ..Plus the GE Customer Service for this product is great. They told me how to fix both problems and had the parts in stock...even now, 18 years later. I paid about $800 for it back then and they're probably about $1200 now. Most of these motel units slide into a standard 16"X42" through the wall box..supplied with them.

Hope this helps,

Don

[woodlaker2]

I've been thinking about putting in one of these units too. Have any of you with these units had any problems with shop dust affecting operation?

[RandyJ]

I've been thinking about putting in one of these units too. Have any of you with these units had any problems with shop dust affecting operation?

I'm not what you would call prolific in the woodworking department, but I've had mine 11 years and never cleaned it. Not all 11 years were woodworking though. A few years it only served as a general DIY shop.
I would think if you cleaned/vacuumed it occasionally it would last for years. MTCW

[MikeL]

Thanks for posting the info on this subject. I have been pondering the best system to use for my shop and it's always good to hear from actual owners.

[mkepke]

I went with a standard large window/thru the wall unit in my shop.

The motel units all max out at about 15K BTUs, which was a little small for my 24x36x9 shop.

GE makes a larger vertical motel unit, but it priced out at close to $1400 after shipping. My 22K BTU Fedder heat cool (electric heat) cost only $600 delivered.

-Mark

[Touchwood]

I've been thinking about putting in one of these units too. Have any of you with these units had any problems with shop dust affecting operation?

In my earlier post I said mine has been running for 18 years or so. These things have a pathetic screen filter in front of the heat exchanger fins behind the front grill. I vacuum mine regularly, but you can see crud building up on the exchanger fins over time..particularly in Summer when it's taking moisture out of the air.

A few years ago it looked so bad that I thought something should be done. The unit was still running OK but anyway....Don't try this at home!.

I took the shop vac and hooked the hose to it's exhaust and pointed it right against the fins with the unit turned off.

The result was astounding (or maybe when you think about it,.. embarrasing).

There was an instant dust storm roaring out of the fan opening that coated me and the rest of the shop with all the accumulated dust the fins had collected over probably ten years. After recovering from the choking and coughing, I put on a mask and goggles, put a plastic tent over me and the unit and kept it up until nothing more was coming out. ..then took a shower.

This is probably a good thing to do once in a while because it will accumulate junk that will reduce efficiency...just take precautions first.

I run a de-humidifier with a drain tube to the outside in the summer and can hold humidity at 35-40%. This helps with dust build up in the heat-pump.

Don

[Touchwood]

I went with a standard large window/thru the wall unit in my shop.

The motel units all max out at about 15K BTUs, which was a little small for my 24x36x9 shop.

GE makes a larger vertical motel unit, but it priced out at close to $1400 after shipping. My 22K BTU Fedder heat cool (electric heat) cost only $600 delivered.

-Mark

Mark,

My shop's the same size and my old 14K BTU GE is fine..in fact can easily over heat the shop to 75-80 degrees at 20 degrees outside.. Resistance heat without a heat-pump is way expensive power wise. Maybe you need more insulation.

Don

[mkepke]

Hi Don - yes, your insulation point has merit. My shop actually has two floors and the upper floor is unfinished as is the ceiling/interface between the two floors. I leave the ceiling open for easy access to the wiring, lights, etc. There has been a plan-in-progress for a while now to do "something" with that upper floor.

The other reason I went with a large unit was recovery time. My shop sits unused and unheated/cooled most of the time, so when I go in there, I want the temperature change to occur rapidly since I'm likely only in there for a couple hours.

When I ran the numbers the premium for a heatpump was something over 12 years payback - approaching the expected life of the unit, i.e. no payback.

After I posted my $0.02 last night, I remembered the other reason I didn't like the motel units for my space was that I didn't want to give up 4' of wall space.

-Mark

[junquecol]

If you aren't maintaining the temp in your shop, then the heat pumps will have a hard time bringing the temp up. They not only have to heat the air, but everything in the shop, including the shop itself. Right now Lowes is getting rid of the wall mounted gas heaters for 75% off. 18K BTU unit is only $50. I use the hanging air filter in my shop to distribute the heated air. Be sure and get an infra red unit, as you instantly can feel the heat. For a bargin on a used Zoneline Heater, check out where a motel is being remodeled. They usually replace all of them at one time. The old ones can often be purchased at scrap prices.

[RayH]

To All:

Thanks for all of your time, thoughts, recommendations, and comments.

Now if I can only get a call-back from the electrician I'll get the project (and my comfort) underway. Silly me. I thought the building trades were looking for work.

Ray