[bldg-sim] EnergyPlus - DOE

[Mahabir Bhandari]

Brian,

 

I think one additional difference from uses’ point of view, which is not
reported in this report, is simulation run time. It seems EnergyPlus takes
5-10 times longer to complete a whole year simulations than DOE2. I was
running a simple 5 story building with VAV system and it took me more than
40 minutes for annual hourly simulations (1 hr time step) in EnergyPlus
while eQuest could run the same building in less than 5 minutes. I am
interested in hearing from others on the run time issue.

 

Mahabir Bhandari

 

 

  _____  

From: Brian Fountain [mailto:bfountain at greensim.com] 
Sent: Wednesday, January 18, 2006 12:12 PM
To: bldg-sim at gard.com
Subject: [bldg-sim] EnergyPlus - DOE

 

That is a big question.

 

For a comparison of current energy simulation software, you could look at
Dru Crawley’s paper comparing 20 tools:

http://www.energytoolsdirectory.gov/pdfs/contrasting_the_capabilities_of_bui
lding_energy_performance_simulation_programs_v1.0.pdf

 

Main differences between DOE and EnergyPlus:  

1)      DOE calculates the space loads for each hour then calculates the
system and plant response for each hour.  EnergyPlus simultaneously solves
the loads the system/plant response for each timestep.

2)      DOE has a fixed 1 hour timestep, EnergyPlus has a variable timestep
(down to 1 minute?).

3)      There are also key issues with the weighting factor assumptions, the
wall convective coefficients.

 

I haven’t used EnergyPlus much yet.  What did I miss guys?

 

Brian Fountain

 

-----Original Message-----
From: bldg-sim at gard.com [mailto:bldg-sim at gard.com] On Behalf Of Renato Sousa
Sent: January 18, 2006 10:56 AM
To: bldg-sim at gard.com
Subject: [bldg-sim] EnergyPlus - DOE

 

Hello everybody.

 

I would like to know if anybody has experience on using both EnergyPlus and
DOE.

Currently I'm using an interface for EnergyPlus. From the software
description I couldn't find out the main differences between EnergyPlus and
DOE. Does anyone know the main differences or where can I find them?