After running your IDF, I found that you have many unusual features.
The DesignDay temperature range is zero. The temperature is constant for the whole day.
Infiltratin is very high, so that Winter cold air and Summer hot air are added to your load.
You have very high internal load in Summer. Therefore high cooling rate. Check the schedule for Winter.
Window heat gain and loas are in the order of 5kw each This adds to your heating and cooling load.
Ground temperature was not endered and assumed to be 18°C. This is keeping your zone temperature high in Winter. No heating required at night. (higher than 10°C)
=========================
I have change some of the schedules and designDay data, and report variables to test the simulation. The infiltration is turned off, and the DesignDay data is from the .ddy file. OA minimum fow is also zero. The heating and cooling rate are now accountable.
the .csv and .idf are attached.
====================
If you are learning to design the building do not use fancy schedules, people, clothings, etc.
Make sure that the building is cool in Summer and warm in Winter, and then add a little HVAC to increase comfort.
Simulation with different equipment will not improve energy usage.
Dr. Li
P.S. for Richard
Are you saying that if the actual type 4 on/off (high/low) setpoint is used for sizing, the maximum available flow rate would be higher, and a temperature change can be met faster. When the peak flow is limited, the fast temperture rise becomes a rounded temperature rise in the simulation, as in most VAV cases.
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: RRaustad@xxxxxxxxxxxx
Date: Mon, 21 Nov 2011 16:42:40 -0500
Subject: Re: [EnergyPlus_Support] Re: Problem with results of a simulation
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The DesignDay temperature range is zero. The temperature is constant for the whole day.
Infiltratin is very high, so that Winter cold air and Summer hot air are added to your load.
You have very high internal load in Summer. Therefore high cooling rate. Check the schedule for Winter.
Window heat gain and loas are in the order of 5kw each This adds to your heating and cooling load.
Ground temperature was not endered and assumed to be 18°C. This is keeping your zone temperature high in Winter. No heating required at night. (higher than 10°C)
=========================
I have change some of the schedules and designDay data, and report variables to test the simulation. The infiltration is turned off, and the DesignDay data is from the .ddy file. OA minimum fow is also zero. The heating and cooling rate are now accountable.
the .csv and .idf are attached.
====================
If you are learning to design the building do not use fancy schedules, people, clothings, etc.
Make sure that the building is cool in Summer and warm in Winter, and then add a little HVAC to increase comfort.
Simulation with different equipment will not improve energy usage.
Dr. Li
P.S. for Richard
Are you saying that if the actual type 4 on/off (high/low) setpoint is used for sizing, the maximum available flow rate would be higher, and a temperature change can be met faster. When the peak flow is limited, the fast temperture rise becomes a rounded temperature rise in the simulation, as in most VAV cases.
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: RRaustad@xxxxxxxxxxxx
Date: Mon, 21 Nov 2011 16:42:40 -0500
Subject: Re: [EnergyPlus_Support] Re: Problem with results of a simulation
The thermostat temperature schedules should not use setback/setup
during sizing periods (i.e., SummerDesignDay and WinterDesignDay
temperature set point should be constant) so that the autosized flow
rate is not excessively high. Then during the actual simulation,
when a setback/setup temperature schedule IS used, the peaks during
"thermostat temperature set up" may not be as high.
Schedule:Compact,
Htg-SetP-Sch, !- Name
Temperature, !- Schedule Type Limits Name
Through: 12/31, !- Field 1
For: Weekends HoliDay, !- Field 2
Until: 7:00,12.8, !- Field 3
Until: 14:00,21.1, !- Field 5
Until: 24:00,12.8, !- Field 7
For: SummerDesignDay, !- Field 9
Until: 24:00,12.8, !- Field 10
For: WinterDesignDay, !- Field 12
Until: 24:00,21.1, !- Field 13
For: AllOtherDays, !- Field 15
Until: 7:00,12.8, !- Field 16
Until: 19:00,21.1, !- Field 18
Until: 24:00,12.8; !- Field 20
Schedule:Compact,
Clg-SetP-Sch, !- Name
Temperature, !- Schedule Type Limits Name
Through: 12/31, !- Field 1
For: Weekends HoliDay, !- Field 2
Until: 7:00,40.0, !- Field 3
Until: 14:00,23.9, !- Field 5
Until: 24:00,32.2, !- Field 7
For: SummerDesignDay, !- Field 9
Until: 24:00,23.9, !- Field 10
For: WinterDesignDay, !- Field 12
Until: 24:00,40.0, !- Field 13
For: AllOtherDays, !- Field 15
Until: 7:00,40.0, !- Field 16
Until: 19:00,23.9, !- Field 18
Until: 24:00,40.0; !- Field 20
On 11/21/2011 4:31 PM, YuanLu Li wrote:
Schedule:Compact,
Htg-SetP-Sch, !- Name
Temperature, !- Schedule Type Limits Name
Through: 12/31, !- Field 1
For: Weekends HoliDay, !- Field 2
Until: 7:00,12.8, !- Field 3
Until: 14:00,21.1, !- Field 5
Until: 24:00,12.8, !- Field 7
For: SummerDesignDay, !- Field 9
Until: 24:00,12.8, !- Field 10
For: WinterDesignDay, !- Field 12
Until: 24:00,21.1, !- Field 13
For: AllOtherDays, !- Field 15
Until: 7:00,12.8, !- Field 16
Until: 19:00,21.1, !- Field 18
Until: 24:00,12.8; !- Field 20
Schedule:Compact,
Clg-SetP-Sch, !- Name
Temperature, !- Schedule Type Limits Name
Through: 12/31, !- Field 1
For: Weekends HoliDay, !- Field 2
Until: 7:00,40.0, !- Field 3
Until: 14:00,23.9, !- Field 5
Until: 24:00,32.2, !- Field 7
For: SummerDesignDay, !- Field 9
Until: 24:00,23.9, !- Field 10
For: WinterDesignDay, !- Field 12
Until: 24:00,40.0, !- Field 13
For: AllOtherDays, !- Field 15
Until: 7:00,40.0, !- Field 16
Until: 19:00,23.9, !- Field 18
Until: 24:00,40.0; !- Field 20
On 11/21/2011 4:31 PM, YuanLu Li wrote:
Check your schedules, internal load, infiltration and ventilation, if any.
Send me the IDF. I will have a look at it, if I have time.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: nachogo27@xxxxxxxxx
Date: Mon, 21 Nov 2011 19:35:50 +0000
Subject: [EnergyPlus_Support] Re: Problem with results of a simulation
Thanks in advance Dr.Li,
It is a simple simulation without HVAC systems,I have only added the Ideal Load
System.
But I have a very high peak load in heating mode when the the target temperature
for my ideal system changes from 12.8ºC to 21.1ºC at 6:00am. How? by schedule?
It seems that my Ideal Load System is switched off because the zone temperature
is near to 18ºC (the target temperature is 12.8ºC,therefore the Ideal System is
off). Real zone temperature is never that low. Do you mean the outdoor temperature is at 12.8°C
But at 6:00am the target temperature changes to 21.1ºC,the Ideal System
switchs on.This is the moment when I got a very high peak(For example,I had a
peak of 80000W at 6:00am and after this peak the load is maintained near to
8000W during only one hour more,after that I dont need more heating).
That is normal. You are changing everything in the zone from 12.8°C to 21°C. After that, you are only maintaining the temperature to balance the incremental solar and inter load.
The flow rate which is autosized is very high,I've tried to manual size it to 2
m3/s but it didn't work. What flow rate are talking about?
I've uploaded the idf file to _Problem_Submittals folder,if you can take a look it would be great.
Thanks,
Ignacio Gomis
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> I am not sure what is your "air heating rate". As your heating load is high during the day, from 6 am, may be you are reporting some roof temperature related variables. A 750m2 roof can be receiving 750kW of heat from the sun. (Assuming 1KW/m2.) The variation of this intensity can be found by listing the solar radiation related variables in your simulation. If you will post or send me the IDF, I will have a look at it. Dr. Li
-- Richard A. Raustad Senior Research Engineer Florida Solar Energy Center University of Central Florida 1679 Clearlake Road Cocoa, FL 32922-5703 Phone: (321) 638-1454 Fax: (321) 638-1439 or 1010 Visit our web site at: http://www.fsec.ucf.edu UCF - From Promise to Prominence: Celebrating 40 Years
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
The primary EnergyPlus web site is found at:
http://www.energyplus.gov
The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/
Attachments are currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
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