Replies

1. 
   Yupster | Oct 02, 2019 10:40am | #1

   Taking a very brief look at it, the simple answer is no. The design static pressure the designer has used is 0.51 in.wc. Your unit can supply a maximum 0.36 in.wc. This is a major error.

   Other criticisms might include:

   Don't use flex duct when hard sheet metal ducting would be a much better substitution.

   Don't take branches off the end cap of a trunk. This makes the trunk very difficult to balance.

   Drawing too much return air from the master suite, the additional air needed can't flow through a typical door undercut.

   The CFM specified is not an actual flow rate produced by this unit.

   That's my takeaway from a brief look.

2. 
   Jon_R | Oct 02, 2019 11:50am | #2

   Ask them what sensible heat ratio (this effects humidity) you are going to get at 1/2 load (a much more common operating point than 100% load) and let us know the answer.

   The ducts are under-sized. Consider moderate over-sizing of all of the ducts. This will reduce fan power, improve balance as flow changes and provide additional flexibility in adjusting balance.

3. 
   Fretted | Oct 07, 2019 07:40am | #3

   Thanks for your reply but I cant get the designer to respond to me now. Dana Dorset gave me the information on the Fujitsu unit but I am not an HVAC guy. I am a little surpprised at the lack of response to my question, I will put this in the mechanical section. I hope someone will respond with some more detailed information and contact info that we can correspond. ( not sure that allowed on GBA)?