Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question

Humidifier latent only

asked 2020-10-06 17:00:40 -0500

Aly ElHefny gravatar image

updated 2020-10-07 12:00:30 -0500

I want to ask if there is a possible way -In EnergyPlus- where I can use a steam humidifier with no sensible heat addition.

Stay safe and Thanks in advance

edit retag flag offensive close merge delete


@Aly ElHefny what simulation tool are you using?

Aaron Boranian gravatar imageAaron Boranian ( 2020-10-07 11:25:50 -0500 )edit

I'm using EnergyPlus

Aly ElHefny gravatar imageAly ElHefny ( 2020-10-07 11:39:05 -0500 )edit

Is this latent-only humidification at the same temperature (only moving straight up on the psychrometric chart) or adiabatic humidification that adds humidity and reduces temperature (move up and to the left along an enthalpy line on the psychrometric chart)?

Do you happen to have an image of the air state changes you want to simulate on a psychrometric chart that you can add to your post?

Aaron Boranian gravatar imageAaron Boranian ( 2020-10-07 12:02:13 -0500 )edit

It will be best if I can find a way to just add moisture with no heating or cooling ( humidify to a moisture content setpoint with no sensible heating or cooling)

Aly ElHefny gravatar imageAly ElHefny ( 2020-10-07 14:36:59 -0500 )edit

1 Answer

Sort by ยป oldest newest most voted

answered 2020-10-08 05:03:00 -0500

Jim Dirkes gravatar image

updated 2020-10-09 10:46:24 -0500

Use an OtherEquipment object and specify 1.0 (100%) in the latent fraction field


Forgot to mention that Fuel Type should be "None". Like this:

  LatentLoad_Veg:Zone1, !- Name 
  None, !- Fuel Type 
  Zone1, !- Zone or ZoneList Name 
  latent_sched, !- Schedule Name 
  Watts/Area, !- Design Level Calculation Method 
  0, !- Design Level {W} 
  20, !- Power per Zone Floor Area {W/m2} 
  0, !- Power per Person {W/person} 
  1, !- Fraction Latent 
  0, !- Fraction Radiant 
  0; !- Fraction Lost

One more thing... My example adds only latent energy by selecting "None" as the fuel type, If you want energy to be consumed then a different object is needed.

edit flag offensive delete link more


This would certainly work if you want to inject moisture directly into a zone. If you wanted to have an HVAC component meet a specific humidity setpoint within single-zone HVAC or a central air system, a different approach would be needed. @Aly ElHefny can clarify what they are hoping to achieve.

Aaron Boranian gravatar imageAaron Boranian ( 2020-10-09 10:50:22 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer


Question Tools

1 follower


Asked: 2020-10-06 17:00:40 -0500

Seen: 75 times

Last updated: Oct 09