On 6/21/2012 7:39 AM, Ray wrote:
I'm considering getting one of those Mitsubishi mini-split air
conditioning systems as an alternative to central AC, with a single
small external unit serving three units inside the apartment.

This is also a heat pump.

I've been told that these systems require a lot of maintenance.

I'd be grateful if anyone could provide experience with these systems.
Thanks.

I just walked in the door having just completed the wiring of 3
Mitsubishi (Mr. Slim) mini splits, each feeding multiple blowers. We set
up a 4 ton unit with 4 line sets and blowers, a 2 ton with 3 sets and
blowers and a 1.5 ton with 2 sets and blowers. I've been wiring these
things (all brands) for years, and never heard of any maintenance
problems. Unlike central systems, these mini splits are all heat pumps
as well, they're very quiet and efficient. The running load on this 4
ton (48,000 BTU) unit is only 23 amps, which includes the 4 blowers it's
servicing. The downside in my opinion, is the ugly line sets on the
outside of the house, and a fairly large blower unit mounted on your
wall. As far as the function, reliability, and economy, I think they're
excellent.