[TRNSYS-users] Type 655 air cooled chiller, Type 508 cooling coil and air conditioningdevices

[Technical Support]

Knut Erik,
 Thanks for letting me know about the confusion in the Type655 documentation.

 I think your approach is correct. I would just be a bit careful about how
the sensible and latent cooling is being handled. The difficulty with
Type508 is that you don't really know how much of the air bypasses the
coil and how much comes to temperature equilibrium with the coil (which
determines how much water is removed from the air stream). The "air side
heat transfer" includes both sensible and latent effects. Unfortunately,
it doesn't split them up for you. You'll have to use Type42 in such a way
that you can reconstruct the sensible/latent ratio.
Kind regards,
 David





Technical Support Team
Thermal Energy System Specialists, LLC
2916 Marketplace Dr, Suite 104
Madison, WI 53719
techsupport at tess-inc.com

>----- Original Message -----
Subject: Type 655 air cooled chiller, Type 508 cooling coil and air
conditioningdevices
Date: Mon, June 23, 2008 3:58
From: knut.erik.enerstvedt at niva.no

> Hello.
>
> While working with TESS Type 655 Air Cooled Chiller in my simulation
> project, I discovered that parts of the documentation and the comments in
> the example data file are misleading. I got the impression that capacity
> ratio should come first on each line in the performance data file and COP
> ratio second, but the model actually reads COP ratio first. I just thought
> that I should make you aware of this, as it confused me a while.
>
> And then I have a question. In my project, I am trying to compare
> efficiency and power consumption for cooling based on an air cooled chiller
> and an air-source split system air conditioning device. I use the Type 655
> chiller, pumps, a fan and Type 508 cooling coil to model a fancoil system
> which cools the zone with the chilled water as source. The system is
> controlled based on the operating temperature of the zone. To compare this
> to a similar split system, I take the "air side heat transfer" output (the
> rate at which energy is removed from the air stream) from Type 508 as load
> input to a split system model (I use Type 42 conditioning equipment to read
> COP under varying conditions and then calculate power consumption from this
> and the load). My assumption is that the "air side heat transfer" output
> from Type 508 is the energy removal rate which is required to cool the
> zone, and therefore can act as a load to simulate an air conditioning
> system which operates under the exact same conditions. I wonder if you can
> verify that this approach is correct, or am I wrong about this?
>
> Thaks for your time.
>
> Kind regards,
> Knut Erik
>
>
>
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