Home Forums Hunting & Shooting Hunter's Campfire Mitsubishi heat pumps - Ductless

Does anyone have these? I'm considering a couple of units for heating and cooling and would like some opinions.

http://www.mitsubishicomfort.com/en/consumer/product-solutions/product-showcase

Thanks guys.

Depends on what you are trying to accomplish. If you think you can adequately heat and cool your home with a couple of these, think again. These mini-splits should only be used where you can't get ductwork. These systems are big easy money for contractors and are sold as a magic bullet to increase comfort and save money. They are pretty much throw away when they break down. Think of this as a fancy window A/C that also heats.

Http://goingductless.com/

Unbiased regional information from the Northwest Energy Efficiency Alliance

A Mitsubishi Mr Slim will cool (sort of) a tent, in Iraq, in the summer, at 110 to 120F. Those things NEVER shut off at the place at Camp Victory that I was in and out of. At outlying camps I stayed at, the Corps of Enginneers had "Quonset tents" that had a more conventional type AC units, about half of them didn't work. YMMV

Can't speak for Mitsubishi's but we have installed a number of Fujitsu's and they work well if sized properly for the job, and they absolutely are not throw away units.....if your installed is qualified.

Used them down in Mexico, and they're pretty quiet, and can cool a room down right now.

I'm liking them more and more.

My house isn't big, maybe 1200 sf. It's a post and beam "saltbox" design and very "open". I have baseboard electric heat that is never used. No access to natural gas or a place to hide duct work. It's 3 levels, a walk in finished basement with an open staircase leading up into the dining/living area. Again, there is another open staircase leading upstairs to the master bedroom, bathroom and 2nd bedroom. It's all very open with ceiling fans in every room. I've been heating with wood for the last 25 years. There is a wood stove in the basement that normally heats the whole house. If it gets below 10* for a few days I may need to put a fire in the living room wood stove. Basically it's the ideal house for heating and cooling with ductless heat pumps. They have one that one that works down to 18* below zero. This is what I had quoted. The dealer gave me several references. All the people I called were very happy with them. I just wanted to throw this out here to see if anyone has experience with them.

Bonneville Power Administration here in the northwest has commissioned several M&V studies, one of which was in HZ 6 (Idaho and Montana). The studies showed COPs at 1.8 to 2.1 at minus 7. DHPs are a very elegant solution for vapor compression heating in existing housing stock of your sort. You can run multiple heads off one compressor for zoning capability. We've been running utility programs with this technology since 2008, it been one the most successful programs I've seen in my 20+ years in energy conservation.

Glad they worked for y'all. I've had to work on a couple of Mr. Slims, and they both ate compressors constantly.

From what I've seen installed on our county projects, they work quote well if sized properly. There are a "local" unit, meaning they have one indoor air handler/evaporator coil. If you need multiple rooms conditioned, or more space than capacity, then you may be looking at two or three units.

I do believe they run and operate very efficiently, like a inverter system, not a one rpm fits all. more demand, they run more, fan runs faster, compressor, etc. Less demand, slower running.

I can't speak to how long they last.

Ductless mini split systems will do what is needed if sized properly.
The Mitsubishi are the best of the brand.
They are used extensively in foreign countries where housing is all hi rise.
Use a qualified installer and you are GTG.

That kind of system has been used effectively in Japan for a long time. Their homes are much smaller than Western abodes, but in my experience with the ones installed in family homes in Tokyo, they are quiet, efficient and effective.

I do have to wonder about the "bubba-factor" here when you confront a typical tradesman with ANYTHING slightly out of the ordinary. Throws most of 'em for a loop.

HVAC guys, I'm sure, don't like the ductless idea because that is grunt work that they can mostly get young bucks to do cheap and make a buck on.

GA Tech did a study in the SE climate years ago and found that judiciously sized AC window units were much more efficient at cooling than ANY ducted forced air system.

Most HVAC installers will not install mastic and properly seal all the ductwork unless forced to do so by code.

Properly installing and sealing ductwork IS code.
Ductless systems are ideal for some applications.
Ducted systems are for most residential and are the only way for large commercial applications.

What constitutes "properly installing and sealing ductwork" in your neck of the woods?

A friend of mine is steering me to the Mitsubishi ductless heat pumps. Claims to have installed them for years with 0 callbacks. Said Sanyo is another good one with no call backs for repair.

I do have to wonder about the "bubba-factor" here when you confront a typical tradesman with ANYTHING slightly out of the ordinary. Throws most of 'em for a loop. this frankly a problem throughout the trades

HVAC guys, I'm sure, don't like the ductless idea because that is grunt work that they can mostly get young bucks to do cheap and make a buck on. Margins also decrease


GA Tech did a study in the SE climate years ago and found that judiciously sized AC window units were much more efficient at cooling than ANY ducted forced air system. duct design is also becoming a lost skill

Most HVAC installers will not install mastic and properly seal all the ductwork unless forced to do so by code. [/quote] and very few can can run a duct blaster or even know what one is

'What constitutes '
Professional workmanship and adhering to building codes.

What does it mean in your neck of the woods?

Thanks guys, I appreciate the feed back.

I agree with this.

Ductless systems, when I was estimating for a contractor, were expensive up front for the equipment but you saved on the fact that no labor was involved in putting in duct work. They are nice for specific situations where duct work is not easily installed. All those Japanese sounding brands were high quality... but I haven't specced any in a LONG time.

But like TBREW401 points out... size it correctly, and that is true for any system. Too large and the dehumidification process gets short-changed, too small and it won't keep up.... its gotta be "just-right" or at least to within 1/2 a ton.