Mini split A/C Heat Pump systems

[justinramani]

Greenmojo,

We use these systems a lot in the military. They work well, but can have issues. The main problem I see with them is service availability. Do you have someone nearby that is willing to work on it if you have issues? There are SOOOO many different brands - some of which are easier to get parts for vs. others. Only other issue I have seen with them is clogged or improperly installed condensation pipes that cause the unit to drip water. My understanding is that Mitsu makes some of the best mini-splits....

 

[greenmojo]

Greenmojo,

We use these systems a lot in the military. They work well, but can have issues. The main problem I see with them is service availability. Do you have someone nearby that is willing to work on it if you have issues? There are SOOOO many different brands - some of which are easier to get parts for vs. others. Only other issue I have seen with them is clogged or improperly installed condensation pipes that cause the unit to drip water. My understanding is that Mitsu makes some of the best mini-splits....

Cool!

Very good points... I have not even looked into any local places to see if they service or repair them. For installation in my temporary office, I bought a vacuum pump and gauges to do the install myself, but that is as far as my HVAC skills go.

The inspector commented on the condensation lines, and said that was their only real concern, that they are properly draining to prevent water from backing up in the house.

~Moses

 

[Sigarms]

If it's a wall mount on an exterior wall, you're fine with a gravity drain. Safety float switchs and mini condensate pumps are readily avialble for mini split systems (in my neck of the woods, they're code anyways).

There are about 90 different brands of mini splits sold in the US. Not one is manufacturered in the US. If you going to spend the money, get a Japanese brand (most expensive) who has been in the US for some time now and not someone jumping on the bandwagon who has a national warehouse in Floriday or California.

 

[techman]

One particular 3 ton multi zone mini split unit at 5 degrees outside air temp can produce over 45k of heat.

I am not sure your numbers are correct, 3 ton = 36,000 BTU, so producing 45,000 seems unlikely. Also as it gets colder the capacity of a heat pump goes down, due to a reduced temperature differential. Most heat pumps are name-plate rated at 45 deg F.

paul

 

[greenmojo]

If it's a wall mount on an exterior wall, you're fine with a gravity drain. Safety float switchs and mini condensate pumps are readily avialble for mini split systems (in my neck of the woods, they're code anyways).

There are about 90 different brands of mini splits sold in the US. Not one is manufacturered in the US. If you going to spend the money, get a Japanese brand (most expensive) who has been in the US for some time now and not someone jumping on the bandwagon who has a national warehouse in Floriday or California.

Funny that you say that. I bought the Pioneer in the temp office from a warehouse in FL.

I am hoping that Mitsubishi is the bigger name brand that will work. I've heard nothing but great about them, and they seem to be marketing the most in an American style (website, commercials, home depot, etc).

~Moses

 

[MacLawn]

I've lived in Japan since '81, house there don't come with any heat/air, so the split systems are all we used. These were invented in Japan. Heat is the weakness just like traditional heat pumps. We used kerosene clean air (intake/exhaust gases to outside) heaters and gas heaters to supplement our heat. The Fujitsu, Sharp, Mitsubishi, Daikin, Toshiba, National (Panasonic here), units we had didn't heat good enough. These are all Japanese makers, the only kind I'd have. Our Sharp was a real workhorse! That thing lasted over 20 years! They were all good brands. Easy to install yourself. I've moved them many times in Japan myself. Had to drill holes up high on walls and make sure house had an outlet nearby the unit. Make sure condensate tray is sloped properly and kept clean. I used a coil cleaning spray annually to clean the coil on inside wall unit. Better make sure you can get parts for your brand in your area. Like karaoke, Hello Kitty, manga, sushi, I have been surprised that these units have come to America! Now if we could just learn to remove our filthy shoes before we enter a house!

 

[Redneck in training]

The minispilts are great technology. I installed a dual zone Mr Slim at our ranch cabin and we are very impressed with the efficiency and quite operation.

If I build a new home I plan to look very closely at them. Be warned that many installers charge a small fortune to put them in. I do not know why as they are easy to install.

They come pre-filled with refrigerant. If you see how they install one you can buy vaccum pump for hundred or so USD and do it by yourself. In fact I would do a better job then the pros would. At least those who installed my split units. I need one large one for the shop sp it will be DIY.

 

[greenmojo]

They come pre-filled with refrigerant. If you see how they install one you can buy vaccum pump for hundred or so USD and do it by yourself. In fact I would do a better job then the pros would. At least those who installed my split units. I need one large one for the shop sp it will be DIY.

That's what I did for the Pioneer unit, I picked up a pump and gauges. Was super simple.

~Moses

 

[chad22]

Although I've never actually had one of those mini splits. I like them. Seems like a better alternative to window acs and much more secure than having a window unit mounted in the window. Though you'd have to secure the ac itself due to theft.

You have to secure everything now. When my window ac's give up then I might look into purchasing one of those mini splits.

 

[Redneck in training]

I don't know much about geothermal. I have plenty of land to do a shallow system over a large area, but I don't know enough about it to know how I would use it.
~Moses

Geothermal works great especially paired with floor heating but at a cost. For the same money you can have all rooms heated/AC by minisplits and PV system to power it all up.