Re: [EnergyPlus_Support] Ceiling space FCU

Okay, so

1) define a seperate zone for your plenum.

2) typically the ceiling is not air tight so you need to use a zonemixing object to exchange some air between the plenum zone and the zone below.

3) the exhaust zone plenum object: it has some features that are nice like extracting heat from the lights, but it not essential per say. It depends what your set up is. So decide where you want to bring in supply air and where you want to exhaust it, both in the zone proper and in the plenumn zone.

Judging from your discription, you want to

FCU

- the fan outlet node name should be one of the zone inlet nodes as normal

- the Fancoil unit inlet node name should be the exhaust node of the plenum zone instead of that of the zone.

now you need to inject the plenum zone with air from the zone

This setup may only be supported by some special types like the PIUs, but if you turn the ODA off it may be much the same as a fancoil.

Check out AirLoopHVAC:ReturnPlenum.

As for heat gain from the ballast, check out the lighting object (I think). I remember that it can be coupled to a plenum, but may only be applicable to exhausted plenums. Perhaps you can split your lighting 50/50, I.e. assign half power lighting to the plenum zone and the other half to the zone...you could of course change the ratios 50/50 to whatever you like.

2014-02-19 11:25 GMT+01:00 Artem Zhukov <artem.zhukov@xxxxxxxxxxx>:

To Jean: Do you mean AirLoopHVAC:ReturnPlenum? How to add there the stratification effect and heat load from ballast? Also I am not get this â??You'll need to include a good amount of air change due to infiltration back and forth accross the ceilingâ??.

From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Jean Marais
Sent: Wednesday, February 19, 2014 10:28 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx; EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] Ceiling space FCU

Check out plenumn objects...basically a plenumn is a basic zone. You'll need to include a good amount of air change due to infiltration back and forth accross the ceiling and possibly substitute the FCU for a equivalent Unitary hvac unit.

2014-02-19 9:13 GMT+01:00 Artem Zhukov <artem.zhukov@xxxxxxxxxxx>:

Dear all,
I want to model the FCU, extract part of which is located within ceiling space. This space has different parameters from room air (I assume, because of stratification and heat from luminaries ballast).

Please help me to find approach to properly reflect this difference in the model.

Thank you

BR,
Artem Zhukov

HVAC Consultant/Building Simulation Engineer

Mob.: +420 774 081 898

SKYPE: zhukov_artem
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