Infiltration pressurization setting in EnergyPlus [closed]

asked 2020-10-16 03:58:58 -0500

Roheet gravatar image

updated 2020-10-16 13:14:00 -0500

When I specify For design flow rate of 0.003 m3/s.m2 (0.6 cfm/ft2) for Infiltration on the facade area, I need to specify which pressure I am using. Building pressurization tests are typically done at 75 [pa] for commercial buildings. I want to set 75 [pa] in Energyplus for pressurization, but I can not find its setting in the Energyplus. Please help me where can I find this setting!

Thanks

@mdahlhausen

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Closed for the following reason duplicate question by Aaron Boranian
close date 2020-10-16 10:46:51.775284

Comments

Are you using the airflow network or the "bulk airflow" approach to model infiltration? The airflow network will calculate the infiltration flow based on pressure values each timestep, while the "bulk airflow" approach will take your design flow rate and apply a fractional schedule that represents how you expect pressurization to change.

Aaron Boranian gravatar imageAaron Boranian ( 2020-10-16 08:21:12 -0500 )edit

@Aaron Boranian I am using "bulk airflow" approach. So based on documents you sent, I need to calculate ACH or design flow rate with 75 [pa] (for example) and put the result in the idf. Actually pressure difference is hidden in the "ACH" or "design flow rate" calculation and there is no filed separately to consider that. Am I right?

Roheet gravatar imageRoheet ( 2020-10-16 08:59:57 -0500 )edit

@Roheet You should enter infiltration at "natural pressure" of ~4 Pa and not pressurization from a blower door test (typically >= 50 Pa), so you'll need to convert your 75 Pa accordingly. This post should answer your question on how to do that. If it does, I'll close this question as a duplicate of the post that I linked to.

Aaron Boranian gravatar imageAaron Boranian ( 2020-10-16 10:04:02 -0500 )edit

@Aaron Boranian That's right! Many thanks for your help :))

Roheet gravatar imageRoheet ( 2020-10-16 10:24:13 -0500 )edit