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Sizing Daikin Mini Split

Matt Potter| Posted inMechanicalson

Looking for some advice sizing ducted mini split. Climate zone 5, 14F design temperature, 13189 BTU/hr load on main floor and 17134 BTU/hr load on basement. Contractor prefers Daikin. Looking for feedback between heat pumps for the 13189 BTU load. The 17134 load is pretty clear I need the RXL heat pump.

Option 1: RXL18UMVJU : @13189 BTU: 43% modulating, 53% low load cycling, 21,600[email protected]
Option 2: RX18UMVJU : @13189 BTU:71% modulating, 26% low load cycling, 12470[email protected]

Option 2 fits better from what I can tell but could the cold weather model still be better? What do they do to make it a cold weather heat pump? Do we want to size these pumps to be “just enough”? Since I will have the other heat pump feeding the floor below and it has some extra BTUs I assume rising the edge is fine for the main floor. Any thoughts? Thanks for the help!

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Replies

  1. Steve Knapp CZ 3A Georgia||#1

    Matt,

    只是好奇为什么地下室负载的家庭r than the main floor load. Basements usually require much less conditioning than above grade sections of a home.

  2. Matt Potter||#2

    I’m not really sure why the basement has a higher load. I don’t have a lot of experience with these, other than my consultant that did the manual j said it was normal to have a higher load in the basement. It is a big house at 2000 ft2 per level. The btu/hr from the manual j seem reasonable from the examples I have seen posted on here.

  3. Steve Knapp CZ 3A Georgia||#3

    Is your consultant an independent HVAC engineer? What he/she told you is the exact opposite of what is typical. Before you do anything, let see if one of the site's experts can review the documents you attached.

    FWIW. Daikin makes great equipment, but you could use Mitsubishi or Fujitsu as well.

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