DIY Home Improvement Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter · #1 ·
I'm looking to heat/cool my garage. I've got a number of machine tools (milling machine, cnc lathe, etc) that are prone to rusting under large temperature swings so I want a system that can maintain a reasonable max/min temp all year (say 50*-80*) that I could then turn up or down accordingly when I'll be working in there for a long stretch of time. That's why I have my sights set on a heat pump system. The garage is about 25'x30' with a standard ceiling height and I figure a 1.5-ton unit should easily be able to manage the space (maybe even a 1-ton?). Some amount of aux-heat would be nice as well, although I can certainly use some sort of small electric heater for the particularly cold stretches of winter. I can spare about 30 amps of 220v for the HVAC.

I see a lot of choices in the "ductless" or "mini-split" heat pump systems. Power- and price-wise these seem right up my alley, but how do you know which ones are any good? I've also been told it would be cheaper in the long run to install an ordinary heat pump system with a full air-handler and minimal ducting, but the full size air-handlers seem to have a lot of power draw.

Does anyone have any good recommendations on both the type of system and the brand? Any alternatives I might not be aware of? I could also achieve my goals with window unit air-conditioners in the summer and separate electric heat in the winter, but that seems really inefficient. I'd prefer to stay away from anything with an open flame or pilot-light for heat because of the various chemicals and such in the garage (stored in a closed metal cabinet, but still...)
 

·
Registered
Joined
·
400 Posts
I think you are right on track with the ductless split option. There are a lot of different makes and manufacturers out there, and some are certainly better than others in both efficiency as well as warranty, however most in the industry will tell you that is far more important that you are happy with the company that will be doing the work.

Ask some refferences of some long time customers and get pricing from a few different contractors so you can weigh the options. Once you have your quotes in; re-post the makes/models that you have and get opinions from there.
 

·
Registered
Joined
·
37,461 Posts
I have one just like this that's been working for years with 0 problums.
I'm using it in an 800 sq. ft. home.
Super quiet, easy to install (even thought the directions suck) only needed 12-2 wire.
Only needed one 3" hole in the wall.
Only thing I had my HVAC guy do was make the final line set connection.
Uses very little power.
http://www.mitsubishicomfort.com/
 

·
Registered
Joined
·
35 Posts
Discussion Starter · #4 ·
Thanks for the quick responses. I've heard very good reviews on the Mitsubishi systems. I was eyeing something along these lines:

http://www.acwholesalers.com/Mitsubishi-Air-Conditioner-Ductless-Mini-Split-p/11221.htm

Unfortunately the good local HVAC place that does the work on my house (when I can't) doesn't do mini-split systems. They have very close ties to Bryant and they don't offer a mini-split system. I had thought about doing most of the install myself and having a professional do the final setup/connections and charge it. They might do that, even if they didn't install the system. Mostly I need to know what power hookups I need to run and where before I finish the insulation and cover everything up. Right now it's a piece of cake to run another 220v hookup, in a couple more weeks it would be a bear of a job.
 

·
Registered
Joined
·
37,461 Posts
The install directions are on the web site.
I chose to install a piece of 2 X 8 where I had cut the wall studs so it would sit flush with the surface to attach the inside unit to.
I had vinyl siding so I removed in in theat area and installed a blank siding block, then reinstalled the siding.
I made up a coil stock cover for it.
Just had to run a wire from the breaker box to an outside disconnect.
The control wires go through the same hole as the lineset in the hole in the wall.
 

·
Special User
Joined
·
917 Posts
I'm looking to heat/cool my garage. I've got a number of machine tools (milling machine, cnc lathe, etc) that are prone to rusting under large temperature swings so I want a system that can maintain a reasonable max/min temp all year (say 50*-80*) that I could then turn up or down accordingly when I'll be working in there for a long stretch of time. That's why I have my sights set on a heat pump system.
I just put a AH123E35AXAA (1-ton) window heat pump in my little machine shop. Thermostat only goes down to 61°F, but perhaps you could use a 240V baseboard thermostat to control the outlet that you plug your heat pump in to, to get down to 50°F.

The garage is about 25'x30' with a standard ceiling height and I figure a 1.5-ton unit should easily be able to manage the space (maybe even a 1-ton?). Some amount of aux-heat would be nice as well,
For that amount of floorspace, you might want the AH183E35AXAA (1.5-ton). Actually if you keep it at a steady 61°F, the smaller 1-ton unit will probably do just fine. It's when you let it get real cold (or real hot in the summer) and want to heat it up (or cool it down) real quick that you need a bigger unit.

Regardless of size though, all Amana "AH" series have built-in aux resistance heat strips for when it gets too cold outside (about 40°F) for the heat pump to work.

I've only had my Amana for two days so I can't give a comprehensive review, but so far mine works and I like it.

If money is no object, look into PTACs (Personal Terminal Air Conditioners). Those are the 4-foot long things you see in many motel rooms. They are quieter, more efficient, and have more features than the window-size heat pumps, but they are quite a bit more expensive and do require a giant hole in your wall.
 

·
Registered
Joined
·
569 Posts
I just put a AH123E35AXAA (1-ton) window heat pump in my little machine shop. Thermostat only goes down to 61°F, but perhaps you could use a 240V baseboard thermostat to control the outlet that you plug your heat pump in to, to get down to 50°F.


(quote)If money is no object, look into PTACs

If money is no object, a mini split unit would be the top choice over a PTAC.
If one plans on using the garage often, keeping the heat pump turned up in the high 60 range would be much more efficient than turning it down low, or even off. Heat pumps have a hard time recovering otherwise.
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top