Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
5

Summer/Winter Design Day Temperature Setpoint Overlap

asked 2016-06-16 17:54:02 -0600

updated 2020-03-07 22:03:21 -0600

For sizing runs in EnergyPlus/OpenStudio, is it possible to have a winter design day temperature setpoint above the summer design day temperature setpoint? It's not atypical to size certain zones to heat to the maximum temperature and cool to the minimum temperature to ensure any temperature within the range can be achieved.

I tried this in OpenStudio and received the following error...

Severe ** DualSetPointWithDeadBand: Effective heating set-point higher than effective cooling set-point - increase deadband if using unmixed air model

My heating thermostat schedule has a winter design day temperature of 75F and my cooling thermostat schedule has a summer design day temperature of 70F. The default profiles are 70F for heating and 75F for cooling.

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
1

answered 2016-06-17 09:46:08 -0600

Archmage's avatar

In EnergyPlus, the schedules can use the special day types "SummerDesignDay" and "WinterDesignDay" to enter in completely different temperature setpoints for the two types of design days.

edit flag offensive delete link more

Comments

Yes, as stated in the original post I am using the WinterDesignDay and SummerDesignDay with different temperature setpoints (75F in winter and 70F in summer). However I am still receiving the error 'effective heating set-point higher than effective cooling set-point' even though my regular day schedules are the opposite (70F for heating and 75F for cooling). The error happens during sizing.

Lyle K's avatar Lyle K  ( 2016-06-17 10:46:44 -0600 )edit

For each type of design day, the cooling setpoint needs to be higher than the heating setpoint when using DualSetPointWithDeadband thermostat control method. You can have a heating setpoint of 75F and a cooling setpoint of 80F during WinterDesignDay, and a heating setpoint of 65F and a cooling setpoint of 70F during SummerDesignDay -- all while still running at heating 70 and cooling 75 during the regular simulation.

Archmage's avatar Archmage  ( 2016-06-17 11:01:43 -0600 )edit

Is there a throttling range for the DualSetPointWithDeadband control method, something that equates to 'effective' setpoint? Is this hard coded or a user input? Haven't been able to find anything concrete in the E+ references. I have some zones where the operational setpoints are 70F heating and 72F cooling, I think this is actually causing my error and not the design days.

Lyle K's avatar Lyle K  ( 2016-06-17 12:35:13 -0600 )edit

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: 2016-06-16 17:54:02 -0600

Seen: 2,062 times

Last updated: Jun 17 '16