The low coil temperature condense out the moisture at say 7°C. The inefficient cooling of the coil allows the return air to be cooled to say 18°C. This is used to feed the ducts. By the time the air reaches the diffusers, it is just cool and dry for the room. No other equipment will be needed.
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I know the above is not what you wanted.
In EPlus, the simulaopn would be a cooler and a reheat system.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Date: Fri, 22 Jul 2011 07:48:16 -0400
Subject: RE: [EnergyPlus_Support] Re: Chilled Water at 2 different Temperatures
Dear Jean,
I think there was a post several months ago regarding this same issue. I am pretty sure that you cannot model two different setpoint temperatures in the same chilled water loop with E+.
Considerations for a workaround:
· The Chilled beam object does not object to colder water, nor does the water flow rate change as long as you maintain the proper delta T ? so energy should remain the same
o You may want to revise the object parameters to make sure the beam performs the same as with warmer water
o I know someone was asking recently in this forum (or Bldg-Sim) about modeling the dewpoint shutoff feature of chilled beams. I did not follow that closely because I felt that most chilled beams systems (in the USA) will use a DOAS that controls humidity, making the dewpoint control less active. Nonetheless, that may be a concern for you. My not-thinking-about-it ?very-long workaround would be to monitor room dewpoint and raise the room setpoint during those periods.
· You CAN use two different chilled water loops and may want to do so for your radiant loop.
o Ideally, you?d like to take advantage of what is probably a higher return water temp from the radiant loop for chiller efficiency. With two loops, this becomes more difficult, but I think you could make an approximation.
The Building Performance Team
James V. Dirkes II, P.E., BEMP , LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Jean marais
Sent: Friday, July 22, 2011 7:31 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Re: Chilled Water at 2 different Temperatures
How do I set up my loops to deliver 6 degC CW to my AHU, but 18 degC CW to my radiant system. One can only have one PlantLoop, right?
If I give my AHU the 18 degC water, I don't get the dehumidification.
If I give my ceiling 6 degC water, I get condensation.
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