Mini-Split in 1k ft Shop and Upstairs Suite

[teal95]

Pretty far along with my shop. It's 32' x 30' with 12' ceilings. 28' of one wall is shared with an unheated garage. 2" of foam under the floor with heating lines in the floor. 600 ft^2 in law suite upstairs. Walls are all 2x6 with fiberglass insulation. Insulation in ceiling of shop/floor of suite. R30 insulation wherever possible and R19 everywhere else. Shop has a 12'x10' door and a 9'x8' door in addition to 2 man doors. I did a quickie heat calculation and came up with 30k for a 65 F differential.

Would I be better getting a single unit mini-split with dual heads or 2 separate systems? 24k sufficient for a/c (I don't see any way I'll ever have to cool more than a 40 F differential) for each head or each system? Wife isn't entirely happy with the idea of cooling the shop but the humidity can make it miserable for a few months of the year.

steve

 

[walrus]

Not sure on costs but seer ratings are going to be better with 2 seperate systems.

 

[theoldwizard1]

Would I be better getting a single unit mini-split with dual heads or 2 separate systems?

If you really are going to heat and cool the shop, dual heads is much cheaper.

You have to learn how to read the specs carefully, especially for heating. Some units stop producing heat between 20-30F while other work until below 0F.

 

[teal95]

The shop will have heated floors. The lines are in, I just haven't done all the research on hooking it up. For now the issue is getting the lines in for upstairs so I can finish the drywall.

 

[Chris Stapley]

Do yourself a favour and look at Mitsubishi Mr. slim units! Very good equipment in comparison with others!

 

[justinjoyal]

A multizone system should be less expensive than 2 separate systems and works great and saves the hassle of having two units sitting outside.

However, if the outside unit breaks, you're out of heat/ac in both places. Also, multizone units are less energy efficient and sometimes the warranty is not the same (depending on the brand).

Do yourself a favour and look at Mitsubishi Mr. slim units! Very good equipment in comparison with others!

Very good equipment, definitely. Better than others? Not necessarily.

 

[teal95]

I'm leaning towards having 2 separate systems. Putting only the one for upstairs right now keeps the wife happy, the system efficiency is better and I can't find a DIY dual head system.

steve

 

[thammel]

I went with 2 separate systems. 9kw in the attic room and 18k in the garage below. Seem to be working quite well.

My motivation was reliability and flexibility.

Tom

 

[justinjoyal]

^^ You mean BTUs ?

 

[teal95]

With a 9k and 18k how big are the areas?