Re: your humidity problem with DOAS... I have noticed that it is important that the sensible AND latent heat recovery device be bypassed when zone humidity is greater than the outdoor air humidity. It crops up again and again because users don't use the outdoor air mixing object when setting up a DOAS and therefore loose the heatrecovery bypass functionality associated with the outdoor air controller object's economizer functionality. My advice is to setup 100% DOAS as if there is a mixing chamber that you may want to use one in a while (such as early morning warmup from setback). It is more realistic and offers the full set of control options.
Mit freundlichen Grü�en- Sent from my iPhone (excuse the brevity)
i. A.
Jean Marais
b.i.g. bechtold
Tel. +49 30 6706662-23
On 16.06.2014, at 08:30, "puranik.sanket@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
SanketKind Regards,The humidity problem has not been solved I am still getting high RH (~ 79%) with DOAS. What can be the problem with the system?Hi,I have modeled VRF system where 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.
I am getting following warnings:
1) "CalcDoe2DXCoil: Coil:Cooling:DX: TwoStageWithHumidityControlMod e="OA COOLING COIL" - Air volume flow rate per watt of rated total cooling capacity is out of range"
2) "CalcDoe2DXCoil: Coil:Cooling:DX: TwoStageWithHumidityControlMod e="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?
__._,_.___
Posted by: "jeannieboef@xxxxxxxxx" <jeannieboef@xxxxxxxxx>
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
__,_._,___