Best mini-spit heat pump?

[MinnesotaEric]

I'm thinking about popping in my own mini-split heat pump. So far the most efficient I've looked at in the 18,000 pound range is a Mitsubishi rated at 21SEER. It also pumps heat down to -13 degrees F.

I've never done this kind of thing before, but as an auto tech, understand automotive AC systems well. Even so, I need to find out what I need to vac the system down and fill it. My install is pretty straight forward: through a upstairs wall on a walkout basement, with a drop 12 feet down to the dirt. I can pop 20amp 220 service out of the basement to service the mini-spit.

Any advice on the install or suggestions on which mini-spit I should look at? I'm in northern Minnesota and am more interested in electrical efficiency for cooling than electrical efficiency for heating.

 

[man00]

You been over to the HVAC forum? I think Mitsubishi is pretty good..That forum is okay but there are some who will try to poke at you for doing the install yourself.

 

[Tractor Seabee]

If you are a proficient auto AC service tech you should have no problem and have all the equipment you need except maybe silver brazing capability (copper lines). Big difference is the piping system being copper and the components are such as filter/dryer and sight glass. A lot of the small package units have pre-charged refrigerant lines factory charged and insulated. The small cans of refrigerant, you probably use at work, may not match the system charge and can get pretty expensive on your new system. You need to get acquainted at your local HVAC supplier. To buy refrigerant there you will need to show your EPA 608 Refrigerant Handlers certification (probably not required for your auto work).

If I lived in MN I would be more concerned about heating costs than AC costs. Or, maybe equally as you probably have hotter summers and a lot colder summers than we do here in the ocean air conditioned PAC NW.

LOL

Ron, former HVACR Service Technician and still 608 certified.

 

[dstig1]

Commissioning Mini-Split Heat Pumps | JLC Online | Heating

R410 for everything, I believe.

 

[brasco426]

Eric all the new mini splits are R410a. You'll just need a standard vac pump to evacuate the piping. Mitsubishi, Fujitsu, Daikin are all good names. When you hang the indoor unit FYI, I like to take the lines attached to the evap and rotate them out 90* to help make it easier making ref line connections. The lines will end up going through the wall and be outside, flaring will be much easier. You'll see what I'm talking about. Also the indoor unit gets its power from the outdoor unit, Carol Cable works nice, you'll need to verify the amount of conductors you'll need. Also look at Slim Duct to run the lines in, makes the install look much better than running them exposed. Happy Cooling. Donnie

 

[ustmd]

In 2009, I sent 4 months doing this research and came to the same conclusion that Mitsubishi Mr Slim was the best choice--at the time. I have had one installed for my home office since then and love it When the main heat pump gives up the ghost, I cam going to convert the entire house to Mitsuibishi mini-splits.

I found this site to be very helpful:

HVAC-Talk: Heating, Air & Refrigeration Discussion

 

[dadster4]

From the advice I've seen you give and the level of knowledge you have shown on anything mechanical, I don't think you will have any problems installing a mini-split system. The units (always) and lineset sometimes) come precharged. If the lines need to be modified for any reason you will need silvfloss and a flow of nitrogen through the pipe while brazing. The fittings on Mitsubishi and Fujitsu units (very similar good specs) are metric- not SAE, and will require adaptors for your standard gauges. If a precharged lineset is shortened, no adjustment to the charge should be necessary when complete (only about 1/10 oz per foot of 410A). Be sure to use the superheat method to check operating pressures with normal ambient temps, both inside and out, when finished. The proper amount of superheat is usually stamped on the rating plate of the condensing unit. A standard rain downspout can sometimes be used to hide the lineset outdoors (cut out the backside to straddle the lineset). I have installed these units in everything from Water Tower Place in Chicago to horse trailers selling tack while at a horse show.

 

[forgeblast]

we have the Fujitsu halcyon with heat pumps, we have 3 of them off one outside compressor, and its one of the best home improvements we did. That being said I would not do the install my self, because you would void the warranty. I was going to install and then just have them come up to pull the vaccum but no warrenty. They did a great job done in two days even wore booties to keep the house clean. Just something to think about.

 

[C4Ranch]

I went with a 4 zone gree. Like it so far and have kept the cabin warm with outside temps in the teens.

Mitsubishi seems to be the gold standard and priced accordingly. In the end, they pretty much have all the same components IMO. The team (4) that installed mine took entire day to run the line sets and covers. 3 rooms plus an upstairs loft. The lines were custom fit lengths and they made sure the inside units drained correctly before leaving.

My system has a feature that measures temp from the unit or remote which is nice.

 

[TomSeller]

Anyone know what operational savings percentage people are seeing compared to a standard heat pump? I know this depends on many factors, including local climate, but I am curious.