How to Simulate Positively Induced (Pressurized) Ventilation in a Zone and Vice Versa using EnergyPlus?

asked 2016-07-28 19:32:20 -0500

ad3_pras

121 ●5

updated 2016-07-29 07:37:49 -0500

Julien Marrec

29032 ●85 ●74 http://www.effibem.com/

Our team has just got a laboratory project that some of its rooms need to be pressurized (positively induced) whereas others are in contrary need to be reduced (negatively induced) by using mechanical ventilation (intake and exhaust fans). Is there any way to simulate this in EPlus? We had tried by utilizing Outdoor Air Unit and Exhaust Fan but it resulted on high number of unmet hours.. Yet our aim is to achieve LEED rating by produce less unmet hours (<300 or so).

We've observed EPlus report also and didn't find anything which depicts this positive/negative zone case, any information on this would be appreciated.

answered 2016-07-29 05:34:45 -0500

Jim Dirkes
3424 ●25 ●15

updated 2016-07-29 07:41:27 -0500

Julien Marrec

29032 ●85 ●74 http://www.effibem.com/

You cannot actually "pressurize" the zone, but you can supply more air than is exhausted or vice versa. Several things should be considered:

1) the unmet hours value is created based solely on whether the space is occupied (any non-zero number of people are present, including 0.01 people ) and whether the space is able to attain the setpoint point value (plus / minus the tolerance you specify)

2) That means you must provide adequate heating or cooling for the zone loads ... with supply air.

3) When the supply and exhaust airflows are not balanced, E+ gives warnings to that effect. As long as you intend the imbalance, they can be ignored.

4) There are two objects which purpose is to allow cross zone mixing (air moving from one zone to another instead of directly back to the air loop). These are: ZoneMixing and ZoneCrossMixing. Check these out for applicability to your project. It sounds as though they will be helpful.