Air Conditioning - Questions About Mini-Split Install
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rickalders
09-05-07, 12:09 AM
I'm seriously considering installing a tri-zone mini-split in my 2 bdrm 1035 sq ft condo. The bedrooms with attached bathrooms measure 290 & 260 sq ft with the living room/kitchen/laundry making up the rest (all 8 ft ceilings, with R-49 installed in the attic). This is an upstairs condo in So California. I got a quote from an A/C shop of $10,800 and that seems way too high so I'm going to self install the major components and have another A/C shop do the final hook-up/system charge (though I am EPA certified to handle refrigerant, I'm not familiar with home A/C or R-410A nor do I want to buy the tools/adapters for this one job). I'm thinking 9k + 9k + 12k/15k (what the thief...sorry estimator...quoted me).
My questions are:
1) Mitsubishi or Fujitsu? Or is there another brand worth mentioning? I need a tri-zone system.
2) Now a really stupid question. Do the indoor unit capacities range so much only because they are limited by the condensor size and total capacity of the system? For example a dual zone 9k + 9k system has an actual capacity of 9k each for a total of 18k.
But take a tri-zone 9k + 9k + 15k system, and the 9k units drop down to a capacity of 7750 each and the 15k unit has only 12900.
(see http://www.designerplumbing.com/specs/ac/mitsubishi/MXZ3A30NA.pdf) for specs.
This would make sense since you can only get 28,400 BTU out of a 28,400 BTU system but (and here is the real heart of this question) when you only run a single 9k unit and the 15k unit (leaving the other 9k unit off) do you get the full capacity out of each of the 2? (I'd rarely use the 2nd 9k unit)
3) The installer who wanted my arm and leg said his quote included a condensate pump in each indoor unit. How do these install? Do they fit directly into the condensate drain hole, or are they somehow butchered into the units? Do the pumps run continously or do they cycle as needed with a float switch? Do the indoor units have reserviors/trays in them where such a device could be mounted? Only one unit would allow me to attach the drain line to an actual plumbing drain so I'd have to use a pump for the other 2 assuming they aren't too hard to make fit. Running the lines outside is not possible. Does anyone have any photos or a diagram they could send me of a pump installed in a mini-split?
Thanks for any help. I realize it's a little late in the season to get much use out of it this summer but I've been miserable for 5 years here and I'm not going to take it anymore (plus I can use the heat pump side of things in the winter).
My questions are:
1) Mitsubishi or Fujitsu? Or is there another brand worth mentioning? I need a tri-zone system.
2) Now a really stupid question. Do the indoor unit capacities range so much only because they are limited by the condensor size and total capacity of the system? For example a dual zone 9k + 9k system has an actual capacity of 9k each for a total of 18k.
But take a tri-zone 9k + 9k + 15k system, and the 9k units drop down to a capacity of 7750 each and the 15k unit has only 12900.
(see http://www.designerplumbing.com/specs/ac/mitsubishi/MXZ3A30NA.pdf) for specs.
This would make sense since you can only get 28,400 BTU out of a 28,400 BTU system but (and here is the real heart of this question) when you only run a single 9k unit and the 15k unit (leaving the other 9k unit off) do you get the full capacity out of each of the 2? (I'd rarely use the 2nd 9k unit)
3) The installer who wanted my arm and leg said his quote included a condensate pump in each indoor unit. How do these install? Do they fit directly into the condensate drain hole, or are they somehow butchered into the units? Do the pumps run continously or do they cycle as needed with a float switch? Do the indoor units have reserviors/trays in them where such a device could be mounted? Only one unit would allow me to attach the drain line to an actual plumbing drain so I'd have to use a pump for the other 2 assuming they aren't too hard to make fit. Running the lines outside is not possible. Does anyone have any photos or a diagram they could send me of a pump installed in a mini-split?
Thanks for any help. I realize it's a little late in the season to get much use out of it this summer but I've been miserable for 5 years here and I'm not going to take it anymore (plus I can use the heat pump side of things in the winter).
Grady
09-05-07, 08:11 PM
1: Sanyo makes excellent equipment but pricey. For the very few installs I do, Sanyo is all I use because of their track record & easy telephone access to tech service should I get in over my head.
2: Don't know. Have never had a need to even look at 3 zone systems.
3: Here, we are not allowed to put a condensate drain into the plumbing drain & knowing California, I seriously doubt it is legal there either. The condensate pumps are float operated & have a high level cut off switch to shut down the unit if condensate is not being removed. I think the pumps are mounted external to the evaporator.
2: Don't know. Have never had a need to even look at 3 zone systems.
3: Here, we are not allowed to put a condensate drain into the plumbing drain & knowing California, I seriously doubt it is legal there either. The condensate pumps are float operated & have a high level cut off switch to shut down the unit if condensate is not being removed. I think the pumps are mounted external to the evaporator.