Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
1

Equation of a system energy provided to the zone in EnergyPlus engineering reference

asked 2018-04-24 23:53:21 -0600

tobeabest's avatar

In Eq (2.3) at Engineering reference v.8.5.0 is as follows. Qsys=msys x Cp x (Tsup – Tz) (2.3)

where Qsys is system energy provided to the zone, msys is system air flow rate, Cp is zone air specific heat, Tsup is supply air enthalpy, Tz is enthalpy of the air leaving the zone. There are no units in document.

So, I guess, Qsys is W, msys is kg/s or CMH, Cp is kJ/kgK, Tsup and Tz are kJ/kg. In this case, overall units do not match.

Am I wrong or typo?

edit retag flag offensive close merge delete

1 Answer

Sort by » oldest newest most voted
1

answered 2018-04-25 09:18:13 -0600

updated 2018-04-25 10:25:34 -0600

Tsup and Tz are temperature in C. I think you are confusing these 2 equations:

Q = Mdot * Cp * (Tsup - Tz)

and

Q = Mdot * (Hsup - Hz)
edit flag offensive delete link more

Your Answer

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

Add Answer

Training Workshops

Careers

Question Tools

1 follower

Stats

Asked: 2018-04-24 23:52:18 -0600

Seen: 99 times

Last updated: Apr 25 '18