Re: [EnergyPlus_Support] VRF Systems

["Michael J. Witte" <mjwitte@xxxxxxxx>]

By VRF, I assume you mean a system where a single DX condensing unit serves two
or more indoor evaporator coils.  Such systems can be heat pumps (or perhaps
usually are?).  From one web site that I found (http://www.vrf-air-
conditioning.com/what-is-vrf.htm)

"The refrigerant flow is varied using either an inverter controlled variable
speed compressor, or multiple compressors of varying capacity in response to
changes in the cooling or heating requirement within the air conditioned space."

EnergyPlus does not have such a model.  The best you can do is model each
indoor unit separately and make some adjustment for part-load performance.  You
are not the first to ask about such systems.  If anyone has access to
performance data for such a unit, I would like to see some.  With good controls
to match compressor capacity with current load, it is quite likely that the
performance of these systems is not much different than a set of individual
systems.  Or perhaps it is even better with very little part-load penalty.  But
I am just speculating about that, I have not data to base that on.

Mike


On 21 Apr 2005, at 1:59, dan_grunbaum wrote:

>
>
> Hi there,
>
> Is EnergyPlus capable of modelling a VRF (variable refrigerant flow)
> system ? If so has anyone modelled a VRF system with EnergyPlus or are
> there any case studies available ?
>
> Thanks,
>
> Dan
>
>
>
>
>
> 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 not allowed -- please post any files to the appropriate folder
> in the Files area of the Support Web Site.
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
>



========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support
EnergyPlus-Support@xxxxxxxx




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