Mitsubishi minisplit 8-head system is not keeping up
Back in mid-November 2016, we had a Mitsubishi Hyper Heat MINI Split installed in our house after opening up the first floor of our home and installing some beams to make it more open. We lost duct work feeding the second floor, and had to come up with a solution. We decided on a Mitsubishi ductless system, since I had a smaller version installed in our detached garage and was very happy with it. My uncle did the garage, while I went with one of the Mitsubishi Diamond Dealers to handle our house. After 3 quotes, we decided on a company and proceeded.
We went with a 4 ton unit outside, and a total of 8 heads inside the house. They are connected via two branch boxes in our attic, one branch box supports 3 heads, the other supports 5. Our house is 2320 sq ft, with 3 heads on the first floor, 12k head in the living room/family room, 9k head in the Kitchen and a 6k head in the breakfast nook. Upstairs there are 5 heads installed, two 6k heads in the master (one in the bedroom and one in the bathroom) and then one 6k head in each of the other 3 bedrooms. The total cost of this system was roughly $22k, and I must say, I haven't been very pleased with this in our house.
My concern is that I feel that the system doesn't keep up with the temp set on the remotes. The remotes are set at either 68-68F, and I feel that the heads run most of the time. It has just started getting pretty cold here in Ohio, but these Hyper Heat units are suppose to handle -13F temps. I'm concerned that there is an issue with the system somplace, and my installer has been slightly challenging to deal with. During most days, the 3 heads downstairs are turned on, and the upstairs heads are turned off, due to heat rising. When we go to sleep, we tend to turn the master bedroom on, as well as our son's room. The temp in the bedroom's seem fine, as the heads are likely oversized for the rooms, but the Mitsubishi doesn't have anything smaller than a 6k head.
I'd like to know what the community here thinks, or possibly what I could check. The detached garage runs like a champ, and I have had zero issues with the two 18k heads installed out there. My other concern is our electric bill/usage. Our past two months have been skyhigh, and according to our meter, we have used twice the amount of electricity than we normally use. November bill stated a use of approx 2500kwH and December was approx 4400kwH. My wife and I are both confused as the system we removed from the house was a 10 year old 13 SEER heat pump and the new units are supposedly 18.9 SEER.
Any help would be appreciated.
Posted Jan 6, 2017 3:59 PM ET
Edited Jan 6, 2017 4:52 PM ET
Other Questions in GBA Pro help