[Bldg-sim] VRF with humidity control DOAS

[Sanket Puranik]

Hi,

I have modeled VRF system but I am getting high humidity for several hours
in an year so I have implemented DOAS system  with humidity control. I took
reference of "DOASDXCOIL_wADPBFMethod.idf" for adding DOAS to control
humidity.

The humidity problem has not been solved and I am getting same RH values as
before adding DOAS. What can be the problem with the system?

I am getting following warnings:
1) "CalcDoe2DXCoil: Coil:Cooling:DX:TwoStageWithHumidityControlMode="OA
COOLING COIL" - Air volume flow rate per watt of rated total cooling
capacity is out of range"
2) "CalcDoe2DXCoil: Coil:Cooling:DX:TwoStageWithHumidityControlMode="OA
COOLING COIL" - Full load outlet temperature indicates a possibility of
frost/freeze error continues."

One more interesting thing I have observed is that VRF system is using
double the electricity for cooling for the same building as compared to VAV
system!! VRF system is supposed to be more energy efficient than VAV
system??

Also I have modeled chilled beam system where I am again facing problems of
high humidity. I am planning to use  same type of DOAS as in the example
file mentioned above. Is it a good way or should I refer to other example
file which would be more appropriate?

Kind Regards,
Sanket
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20140616/a4ee11cf/attachment.htm>