ac/heat pump in the ceiling

[Bill Dufour]

I am thinking about installing a mini split ac unit in the shop. this will be ac and heatpump unit. my shop is a converted garage. Any one ever used a minisplit evaporator flush mounted in the ceiling? Not sure how condensate would drain. It may have to be pumped outside.
Bill D.

[David Buchhauser]

Hi Bill,

I assume that you are talking about installing the evaporator in the stock orientation (as shown in the 2 photos), but instead of mounting on the wall you want to recess it up into the ceiling. I think this would depend on the distance between your interior ceiling and the exterior surface of your roof. If you have an attic above your garage ceiling with enough height - then I think this would work. These mini-split evaporators usually have a specified distance between the top of the unit and the ceiling for sufficient air flow. They also specify a minimum distance from each end of the unit to any adjacent wall. I would imagine that if you built some sort of recessed box up into your ceiling with enough height and volume you could make this work. You could use a small condensate pump to take care of the condensate.

David

[George Makra]

You will either have to install a condensate pump (most manufactures will sell one that fits inside their unit.
Or if you have the capability a gravity drain line with a 1/4 inch per foot fall.

[Dan Friedrichs]

The air inlet may be on the top, restricting how close to the ceiling you can put it. Check the manual for the unit you're considering to see minimal spacing requirements.

Condensate can be pumped out, or if you can drill a hole through a wall...

[Kurt Cady]

Several mini splits have ceiling registers. Check the install instructions on those registers.

[Jack Frederick]

You are talking about the "ceiling cassette" style units. Generally they will have a very low head condensate pump built in. The Fujitsu's would pump up to 16" and then you would have to have a drain line or another cond. pump from there. They are more difficult to clean as you have to either work overhead or crawl to the unit from above. Mini-splits are great technology and very efficient, but the key to long term success with them, in my opinion, is the ability to clean them easily. In my experience that means the high wall evaporator. Ceiling cassettes in a conference room or office setting are fine, but I wouldn't want one in the shop. Something to keep in mind also if you go high wall, some manuf will let you get as close as 2" from the ceiling. That sounds good as you can tuck it up there nicely, but about 40% of the coil face angles down the back of the unit and if placed to close to the ceiling it too is a pitn to clean or inspect. As I write this I am looking at just such an installation in my kitchen;(

[Jim Becker]

The one in my shop is a "conventional" MiniSplit on the wall, but a good friend has a ceiling mounted unit in their kitchen (lofted trey ceiling) and it works very well, especially for cooling since cold air goes down) The only difference between a wall and ceiling mount unit is the form factor. The one challenge with a ceiling mount unit is that it's a little more difficult to do regular filter cleaning. In a home, that's not very frequently, but in a shop, we need to do that a lot more often simply because of what we do. I do the filters on my unit at least monthly and sometimes sooner if I've been cutting a lot on the CNC which is close to the wall mounted system.