Hisham,
An “air curtain” in the USA is strictly a fan that recirculates air at a door. Occasionally it has a heating source. (For some automotive applications, it is also uses 100% outdoor air!)
· A recirculating fan cannot change zone air pressure, only the micro-climate pressure in the immediate vicinity of the door. (Consider the definition of 100% recirculation!)
· The device normally cycles on when the door opens, and may have a minimum operating cycle time, so you will need to determine approximate operating time and reflect it in a schedule.
o The fans often discharge air at high velocity (20 m/s | 4000 f/min) and are fairly low efficiency, so they use significant power.
· If they have heating capacity, discharge temperature is often fixed at about 35-40C. (You should confirm this with the design engineer or temperature controls schematics)
· It seems impractical to precisely account for mixing between zones, but you might assign a fraction to each of the adjacent zones. I think I would put all the energy in the “cold” zone (e.g., warehouse)
Good luck! This should not be difficult for you.
James V Dirkes II, PE, BEMP, LEED AP
www.buildingperformanceteam.com
Energy Analysis, Commissioning & Training Services
1631 Acacia Drive, Grand Rapids, MI 49504 USA
616 450 8653
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of jeannieboef@xxxxxxxxx
Sent: Wednesday, December 11, 2013 2:26 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Cc: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] Air Curtains Modeling
If anyone has some experience modelling air curtains in e+, I would also like to know.
I would guess the space is over pressurized. Check the AHUs air balances. A percentage of the heat from the unit will be locally lost without "entering" the zone proper (much like a cooker with a hood exhaust).
A good place to start is a manufacturer data sheet. Keep us posted.
On 11.12.2013, at 06:11, "hisham.rashrash" <hisham.rashrash@xxxxxxxxx> wrote:
Dear all,
I have a warehouse project where hot-water-heated air-curtains are installed over gates for storage spaces and electrically-heated air-curtains are installed over doors for offices.
I am not sure how to model them. Should these be considered as internal loads? then I am not sure of what schedule to follow, also, not sure about the way I should account for mixing of cold air running into zones when gates or doors assumed open and air-curtains are running.
Total power for these air-curtains is 2.5[MW]!!!
Please advise.
Thank you very much.
Hisham
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