modulating minisplit
I am about to close on 2 condos in NYC investment has one of those gigantic 2 fan outdoor units from Gree that I know is way oversized after being on GBA community.
I believe is a 36k BTU unit and the indoor heads are 12K, 9K, 7K, 7K. Given it would be too costly to change at this point if the min outdoor capacity is 50% of the 36K BTU and lets say I only turn on the 12K indoor unit does that mean it wont run or it will just not run efficiently at all and be prone to problems in the future.
The other smaller unit is a smaller one fan 28K BTU unit where the indoor heads are 12, 9, 7. Same deal as before do i need to turn on at least 2 of them in order for it to work since the min operating capacity from their submittal is 50%?
The price of the condo was too much of a steal to not take up and had to park some cash in this so backing out is not an option now.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
The 50% number is the installable capacity of indoor units. So a 36k outdoor unit can have as little as 18K of total indoor unit capacity connected to it.
The outdoor units generally modulate a bit lower (typically it a 3:1 turndown on these) but it still won't be all that great. This means the units will be cycling which is not the best for efficiency of comfort but it will still work. I can't see a tenant ever complaining about this.
Thanks for the input Akos. So even if 1 unit of 7k indoor is working for the large 36k BTU outdoor unit and the other 3 are off itll still work but itll be crappy. But if say if all 4 of them 9k, 9k, 12k, 12k for a total of 42k is on at the same time it should still work fine if the outdoor unit is 36K btu since the total capacity was 135% of 36K which is around 42K BTU.
Definitely for my own home we are going with 1 tot 1.