Ductless split mini systems

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Old 05-03-07, 12:03 PM
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Ductless split mini systems

How well does a ductless split-mini with heat pump work when it is cold out? Do such systems out-right shut down at certain temperatures if they do not have a auxilliary/backup heater? Or does the efficiency of the system merely get less but it keeps working? For a modern system, how cold does it need to be before a heat pump is less efficient than electric baseboard units -- I think that means COP = 1?

As for my particular situation, I have a older cape cod style home in DC area and am trying to add ac and heating to upstairs so that it can be used for a regular bedroom for the kids whereas it currently is a guest room. For winter temperatures, this year's coldest low was +7 degrees F, and the all-time record low in our area is -10 (minus 10) degrees F. The three proposals that I have received are all for 1 ton split-mini systems with heat pump (but no auxilliary/backup heaters). As a result, I have generally presumed that a split mini (of that size) is the way to go. However, if baseboard electric heaters are needed to supplement, I'd be very tempted to make the baseboard electric heaters the primary system and do a window ac -- it'll be a lot less expensive to install.

Thanks.
 
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Old 05-03-07, 08:23 PM
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Wink

You have to have electric heat back up in them for when it get real cold . Also you need it for back up when the unit has to go into defrost.
 
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Old 05-04-07, 05:31 AM
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That is my concern. Many or most 1 ton ductless split minis do NOT have back-up heaters, and none of the proposals for my home included back-up heaters. (Two proposals were for Sanyo 12KHS71.) So what does a system without a back-up heater do when it gets really cold? Shut down or just operate in a less efficient way?
 
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Old 05-04-07, 05:45 PM
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Any unit when it starts to get down to 32o has to go in a defrost time to time so you have to have back up electric there. If not it will blow cold air into the home.
 
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Old 12-26-07, 05:51 PM
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I have a Samsung 18000 Btu installed in the bonus room over my garage and it has worked great. I have it set on 69 and it has never gotten below then 64 even on defrost. The fan on the unit runs all the time and there has never been any cold air coming from it. When the unit is in defrost the fan runs at a very low RPM. Even at 10 degrees outside it was still heating the space. The Samsung unit is a little higher tech then the other units and SEAR is 17 which is higher then most. Our unit has just been installed for two months but we are happy with the performance so far.

Roger
 
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Old 12-20-08, 03:33 PM
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Originally Posted by rogerh View Post
I have a Samsung 18000 Btu installed in the bonus room over my garage and it has worked great. I have it set on 69 and it has never gotten below then 64 even on defrost. The fan on the unit runs all the time and there has never been any cold air coming from it. When the unit is in defrost the fan runs at a very low RPM. Even at 10 degrees outside it was still heating the space. The Samsung unit is a little higher tech then the other units and SEAR is 17 which is higher then most. Our unit has just been installed for two months but we are happy with the performance so far.

Roger
Hi Roger,
It's been over a year, how is that Samsung working?
Did it do a good job cooling in the summer, and is it still heating your bonus room this winter?

I've been thinking about buying a Samsung 18,000 or 24,000

and have been wondering about those "Low Ambient models".. (Since I live in Mass).
24KHS72 - Sanyo 24,200 BTU Heat Pump Air Conditioner Kit
What model did you get?

Thanks,
Rich
 
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Old 11-05-09, 11:47 AM
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Installed!

Mine is working okay, but it remains to be seen, if it does well in really cold weather.
Around here, 20 degs F is considered really cold.

Here's a link to the install..

Sanyo 24KHS72 AC/HP DIY install project - EcoRenovator
 
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