more mini-split-ness

more system research changed a few small details of the systems i listed previously..

the low-heat (17F) capacity of the fujitsu system i listed was incorrect. that figure was the cooling capacity at 17F (don't ask me why they list the cooling capacity of the system at 17F..) heating capacity of the 24rmlq-c is actually 25.4kbtu/h, which is more than i need.

there is a smaller fujitsu system available, the 18rmlq-c. this system includes a 24rml1 outdoor unit, and two aru9rml indoor blowers. i am over 95% certain this is the system i will be ordering. specs:

cooling capacity: 11-22.6kbtu/h
heating capacity: 11-26kbtu/h
EER:10.6 SEER:15 HSPF:8.6 COP(heating):3
low-heat (17F) capacity: 21kbtu/h
price: $2500

the heating & cooling capacity ranges listed on the spec sheet are what is available from the system at a specific indoor & outdoor condition.
cooling conditions: 80F.DB/67F.WB indoor, 95F.DB/75F.WB outdoor
heating conditions: 70F.DB/60F.WB indoor, 47F.DB/43F.WB outdoor

the fujitsu tech manual also provides a table listing system performance under various combinations of indoor & outdoor temperatures. total capacity and power input of the system for each combination is provided. a look at the cooling table should provide insight into the system's dehumidification potential during the cooling season:


look at the 80F indoor column and the 95F outdoor row.. the TC here is 22.6kbtu/h, same as the max capacity listed in the main spec table. milder days of say 77F outdoor.. with an indoor temp of 70/75F.. TC is about 20kbtu/h. this is the maximum TC.. the spec sheet range of 11-22.6 could be roughly scaled to say 10-20kbtuh.. perhaps a minimum of a little below 10kbtu/h.

this table doesn't specify the outdoor wet bulb. if i assume the same WB for all outdoor conditions, say 77F.DB/75F.WB, and plug that into rhvac along with a 70F.DB/60F.WB indoor condition, then rhvac gives me a cooling load of 9k-9.5k (depending on if the house is extremely air tight or average air tight).

so if my assumption of outdoor wet bulb is correct, then this system should be able to very nearly match the load during mild summer conditions.

ok, i am going to move on with the assumption of selecting this system for purchase. next, i need to determine all of the equipment and accessories i will need for installation.