Mini-split heat pump end of season review

[Forty Two]

Hi all. The last thread generated a lot of interest in the inexpensive, super efficient mini-split heat pumps as an excellent supplement to the main heat source in your home.
You can follow the discussion on this thread: http://ecomodder.com/forum/showthrea...tion-6344.html


I bought an Amcorcaire 12,000 btu mini split heat pump in October and put it through its paces in a cold minnesota winter. I thought I'd create a thread for people to share their results and give us a chance to compare performance. I'll post the results to the variables that seemed most relevant to me. I don't have access to much in the way of testing equipment so please don't ask for exact breakdowns on kwh, etc. If I knew the number, I'd post it.

First- the price. I bought from here:
mini split air conditioner - ductless split system
and had a good experience. As you can see, the total cost was around $1200. The shipper dropped three boxes off in my driveway within a week of ordering the unit.
The instructions were good, but not great. There were a couple of wires that didn't have consistant connectors, and required my snipping and connecting in a custom way- but nothing too hard.
I ran my pipes inside of a rain gutter to hide them and improve the appearance. The pipes come wrapped with a foam insulation and a white cover.
I hired an HVAC professional on craigslist to check out my install, and evacuate the lines. It took about 90 minutes- but could go faster if you avoided the double checking of everything. I paid him less than $200 for his help.
The unit has a SEER of 20 and a HSPF of 10.1
The unit has an inverter which allows the compressor to vary the speed at which it moves the heat. It attempts to throttle itself to a consistent speed to match the heating or cooling required.

After one hard winter here's what I found:
Running the unit hard, it would replace all the heat upstairs and 50% of the heat on the first floor. This could leave the basement really cold.
The electric bill went up by about 1/3 (+$45) during the coldest months.
The gas bill dropped by 1/3-1/2 (-$100) during the coldest months.
The unit effectively increased the comfort and heating to 600 sq feet of house that wasn't adequately serviced by the existing ductwork- so it provided much more than just heat to replace the existing system.

The unit worked well to around 5 degrees F. It began loosing heat output as the tempertatures dropped until it shut itself down around -5 F.
The unit automatically defrosts by reversing the cycles- not resistence heat- making the defrosts fairly efficient.

The unit only needs 120v service and is easy to wire for someone with a limited electrical experience.

The unit is quiet except for the oscilating plastic panels. They can creak or crack from time to time- possibly waking a light sleeper. I turned off oscillation at night.

Maintenance: washed the filter screen twice. It is plastic and easy to clean by running it under the tap.

Final verdict: The unit is an amazingly efficient and versatile machine. If I could do it again- I would buy another for the main floor, or simply install on the main floor. It is great to have the upstairs climate controlled and makes it much more usable, but to really save money- install it in the main living areas.

Don't be afraid to order one and get some help from a pro off craigslist. My unit is almost identical to a unit my friend has- he paid $12,000 for two of them installed. I paid about $1400 for one- and did it myself.

Any other successful installs out there?