Ductless Mini-Split

Earnie · 08-01-2010, 03:09 PM

This is not really a DIY question, but thought it would be an interesting discussion.

Why is this technology not used more in the US?

This unit appears to answer many needs caused by poor duct assembly and attic or crawlspace duct installation.

http://www.daikin.com/global_ac/prod...lus/insta.html

yuri · 08-01-2010, 04:15 PM

COST $$$. The better ones are all imports, Fujitsu, Sanyo, LG, Mitsuibishi and expensive. They are very popular in Asia. They are good for A/C but cannot produce much heat with a heat pump or have add on electric heat so that eliminates all the States that need supplemental electric heaters in the ductwork for cooler times of the year.

Proby · 08-01-2010, 04:17 PM

I also find them loud. With central AC you only have a small register or two which is more visually pleasing than having a unit mounted on the wall.

COLDIRON · 08-01-2010, 07:46 PM

LOUD, You sure yoo are talking about minisplit uints??

Proby · 08-01-2010, 08:07 PM

Quote:

Originally Posted by COLDIRON

LOUD, You sure yoo are talking about minisplit uints??

Absolutely. I've wired up many different units over the years. Every single one of them has been louder than properly installed central AC.

**beenthere** · 08-02-2010, 07:34 AM

Quote:

Originally Posted by Proby

Absolutely. I've wired up many different units over the years. Every single one of them has been louder than properly installed central AC.

Strange. I've only installed a few that were anywhere near being loud.
The vast majority you can't hear the blower running most of the time.

What brands and models did you wire in that were loud,

Proby · 08-02-2010, 08:44 AM

Quote:

Originally Posted by beenthere

Strange. I've only installed a few that were anywhere near being loud.
The vast majority you can't hear the blower running most of the time.

What brands and models did you wire in that were loud,

The majority I've installed over the years have been Mr Slims, but I have worked on my fair share of Fujitsu and LGs.

Volume is hard to describe in itself. A cellphone is loud in a quiet movie theater, but yelling is quiet at a gun range. The only way to describe volume is a comparison. Split units are quiet compared to window or wall units, however, they are louder than central AC (which is what the thread starter was comparing it to).

**beenthere** · 08-02-2010, 08:54 AM

I can't say that they are in all applications. Sounds like the ones you wired were not installed quiet properly.

Like I said earlier. Many you have to try to hear running. Specially the newer ones with inverter condenser units.

Proby · 08-02-2010, 09:01 AM

Quote:

Originally Posted by beenthere

Sounds like the ones you wired were not installed quiet properly.

Maybe so, but I doubt it. They were installed by many different contractors over a period of many, many years. I refuse to believe that they were all installed incorrectly.

Earnie · 08-02-2010, 01:11 PM

So the drawbacks could be:

1 - No emergency heat function.

2 - Cost which can be subjective.

3 - Sound, which again is subjective.

4 - Aesthetics, maybe also subjective.

Do the units truely provide better cooling vs a heat pump?

What about heat vs a heat pump?

Has anyone installed one of the multi-zone units? I know there are benefits to standard zoned systems.

yuri · 08-02-2010, 01:26 PM

They provide the same amount of cooling as a heat pump. Only difference is the reversing valve in a heat pump allows the reverse cycle. Heat pumps lose their heat output proportionately as the outside temp drops and cost more to run at lower temps/produce less heat. Google: air to air heat pumps for more info. http://oee.nrcan.gc.ca/publications/...sheatpumps.cfm

http://www.fujitsugeneral.com/wallmounted9-12RL.htm
Fuji makes some VERY high end high SEER units
Sound is very quiet from my experience. Although a high end air handler or furnace with a variable speed ECM motor/blower can be EXTREMELY quiet if setup properly with correct sized ducts.

**beenthere** · 08-02-2010, 05:52 PM

Some units stop running at an outdoor temp of 13°, others still provide heat at -10.

Depends on what brand/model your getting. They can deliver 80% of rated heat at very low temps. Compared to regular split system heat pumps.

BRO931 · 08-03-2010, 04:51 PM

I've installed two mini-split heat pumps at my residence in North Carolina where temps have ranged from 0 to 100 F. They are Friedrich M18Y3F units and they both worked flawlessly in heat and cold for 4 years until one of them stopped cooling a few weeks ago. Service guys says lightning got to it. Hopefully a new control board is going to put that unit back on line soon.

Both are indeed a bit loud when blowing on high speed, but the ultra-quiet low speed setting is virtually silent. Of course you don't get 18000 BTU/hr on low speed either. Comparing the noise of a mini-split to one duct on a central HVAC system is comparing apples to oranges.

Regarding efficiencies, my "inverter" mini-splits tune themselves to the required heating or cooling load and seem to be very efficient. But they cost more too.

Proby · 08-03-2010, 05:06 PM

Quote:

Originally Posted by BRO931

Comparing the noise of a mini-split to one duct on a central HVAC system is comparing apples to oranges.

I disagree. The whole point of this thread is a discussion on why minisplits aren't used more often in comparison to central air. Citing the noise difference between the two systems is very relevant.

Red Squirrel · 08-03-2010, 05:08 PM

Cost is probably the factor. I looked into one of these myself, as some can actually be done DIY, the refrigerant tube has a special connector kinda like a quick switch air compressor connection. But at their cost, may as well pay a bit more for central AC.

Ended up buying a portable unit instead, though I sometimes regret not getting a through the wall unit. The portable unit is east to setup, but is VERY loud and inefficient. It gets the job done though.

Mini splits will be louder then central AC because the fan is in the unit itself, not in the basement in the furnace, but the portable units will be even louder.