Hi, Alexis
I had a look at your IDF.
It was a good IDF, but you did not ask for any variables to be displayed, and there were no DesignDay objects.
The monthly report show you the averaged monthly values, and is not easy to figure what is acturally happening with the building.
I have added some variables in the IDF attached. There are a lot more than those listed ones in the .rdd file.
In order to keep the .csv file small, I only asked for the hourly data to be included. You can custom this .csv file using the .rvi and .eso files.
You can see that the cooling load is mainly the heat through the windows, about 8kW per floor. In Winter, the sun radiation helps to reduce the heating load.
The skyclearance was set to zero in the DesignDay object for Winter, therefore you did not have sun radiation helping the heating in the .csv.
The ground floor windows have an over hange by the first floor. Therefore, the solar heating is less.
The blind is not working. The blind slat angle = 0 means it is off and not at zero angle. There was a question on this topic a few days ago.
I have turned on the daytype index, and the schedule values to help debogging.
The diabostics are also turned on. The SQL file will allow you to use the RessultViewer.
If you any more question, please do not hesitate to aske me, directly to my e-mail ID, if you wish.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: alexiskirk2000@xxxxxxxx
Date: Mon, 16 Jan 2012 22:19:35 +0000
Subject: Ó÷åô: [EnergyPlus_Support] Excessive Cooling Load Using Ideal Load Air System
Áðï: YuanLu Li <yli006@xxxxxxxxxxx>
Ðñïò: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
ÓôÜëèçêå: 11:46 ì.ì. ÄåõôÝñá, 16 Éáíïõáñßïõ 2012
Èåìá: RE: [EnergyPlus_Support] Excessive Cooling Load Using Ideal Load Air System
You mentioned that
"The building is sufficiently insulated and has a large number of large openings to the south."
It is difficult to tell without looking at the IDF to see what these openings are, and how they are modelled..
================
The following are some of my observations and suggestions.
If these openings are windows, you can expect very high cooling load through them. You can look at the window heat gain, etc. to separate the heating source in Summer and Winter. Ceiling and roof insulation can also affect the cooling load.
The Winter in Thessaloniki is rather mild. Therefore, the cooling load may appear higher as a ratio. At 40 degree latitude, the windows facing North can also be receiving high solar radiation in Summer. The South facing windows are reducing the Winter heating load.
To save simulation time, you only need to run the sizing simulation using the DesignDays, and list the heat transfer variables for the building.
Move the theremostat to 35°C in Summer and -3°C to turn off the HVAC. Display the zone mean temperature, to see whether there are unusual temperature distrubution in the building. For example, colder or hotter third floor may suggest insufficient insulation for the cieling. High ground floor temperature may suggest the use of too high building ground temperature.
Ventilation and infiltration can also change the temperature profile.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: alexiskirk2000@xxxxxxxx
Date: Mon, 16 Jan 2012 20:32:13 +0000
Subject: [EnergyPlus_Support] Excessive Cooling Load Using Ideal Load Air System
__._,_.___
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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I had a look at your IDF.
It was a good IDF, but you did not ask for any variables to be displayed, and there were no DesignDay objects.
The monthly report show you the averaged monthly values, and is not easy to figure what is acturally happening with the building.
I have added some variables in the IDF attached. There are a lot more than those listed ones in the .rdd file.
In order to keep the .csv file small, I only asked for the hourly data to be included. You can custom this .csv file using the .rvi and .eso files.
You can see that the cooling load is mainly the heat through the windows, about 8kW per floor. In Winter, the sun radiation helps to reduce the heating load.
The skyclearance was set to zero in the DesignDay object for Winter, therefore you did not have sun radiation helping the heating in the .csv.
The ground floor windows have an over hange by the first floor. Therefore, the solar heating is less.
The blind is not working. The blind slat angle = 0 means it is off and not at zero angle. There was a question on this topic a few days ago.
I have turned on the daytype index, and the schedule values to help debogging.
The diabostics are also turned on. The SQL file will allow you to use the RessultViewer.
If you any more question, please do not hesitate to aske me, directly to my e-mail ID, if you wish.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: alexiskirk2000@xxxxxxxx
Date: Mon, 16 Jan 2012 22:19:35 +0000
Subject: Ó÷åô: [EnergyPlus_Support] Excessive Cooling Load Using Ideal Load Air System
Dear Dr Li,
Thank you very much for you time and consideration, I 'll make sure to look thoroughly into your suggestions and observations. I am also sending you the IDF in case you are interested in getting a better view concerning the issue mentioned.
Áðï: YuanLu Li <yli006@xxxxxxxxxxx>
Ðñïò: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
ÓôÜëèçêå: 11:46 ì.ì. ÄåõôÝñá, 16 Éáíïõáñßïõ 2012
Èåìá: RE: [EnergyPlus_Support] Excessive Cooling Load Using Ideal Load Air System
You mentioned that
"The building is sufficiently insulated and has a large number of large openings to the south."
It is difficult to tell without looking at the IDF to see what these openings are, and how they are modelled..
================
The following are some of my observations and suggestions.
If these openings are windows, you can expect very high cooling load through them. You can look at the window heat gain, etc. to separate the heating source in Summer and Winter. Ceiling and roof insulation can also affect the cooling load.
The Winter in Thessaloniki is rather mild. Therefore, the cooling load may appear higher as a ratio. At 40 degree latitude, the windows facing North can also be receiving high solar radiation in Summer. The South facing windows are reducing the Winter heating load.
To save simulation time, you only need to run the sizing simulation using the DesignDays, and list the heat transfer variables for the building.
Move the theremostat to 35°C in Summer and -3°C to turn off the HVAC. Display the zone mean temperature, to see whether there are unusual temperature distrubution in the building. For example, colder or hotter third floor may suggest insufficient insulation for the cieling. High ground floor temperature may suggest the use of too high building ground temperature.
Ventilation and infiltration can also change the temperature profile.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: alexiskirk2000@xxxxxxxx
Date: Mon, 16 Jan 2012 20:32:13 +0000
Subject: [EnergyPlus_Support] Excessive Cooling Load Using Ideal Load Air System
Dear Group,
I am simulating a three storey building in Thessaloniki Greece, a region rather cold than hot, in order to estimate the anual loads for heating and cooling. The building is sufficiently insulated and has a large number of large openings to the south. Internal gains - occupants,lights and devices- and infiltration and ventilation loses have been taken into account. The simulation is implemented for constant heating setpoint at 21 C and constant cooling setpoint at 26 C. The building has no shading device. Regearding the HVAC system I used HVAC Template:Thermostat and HVAC Template Zone:Ideal load Air System with the above mentioned thermostat setpoints. In general, everything was done according to the Input/Output Manual and after consulting the idf.example files. What is amazing is the fact that the cooling loads are almost three times higher than the heating loads, something rather abnormal for the region of Thessaloniki. Is there a logical explanation regarding Ieal Load Air System and high cooling load estimation even in cold regions?I am very curious to find out what is qoing on because from what i ve read so far both in older posts in the group and in the input/output file the Ideal Load Air System works efficiently. Any suggestion?
I am simulating a three storey building in Thessaloniki Greece, a region rather cold than hot, in order to estimate the anual loads for heating and cooling. The building is sufficiently insulated and has a large number of large openings to the south. Internal gains - occupants,lights and devices- and infiltration and ventilation loses have been taken into account. The simulation is implemented for constant heating setpoint at 21 C and constant cooling setpoint at 26 C. The building has no shading device. Regearding the HVAC system I used HVAC Template:Thermostat and HVAC Template Zone:Ideal load Air System with the above mentioned thermostat setpoints. In general, everything was done according to the Input/Output Manual and after consulting the idf.example files. What is amazing is the fact that the cooling loads are almost three times higher than the heating loads, something rather abnormal for the region of Thessaloniki. Is there a logical explanation regarding Ieal Load Air System and high cooling load estimation even in cold regions?I am very curious to find out what is qoing on because from what i ve read so far both in older posts in the group and in the input/output file the Ideal Load Air System works efficiently. Any suggestion?
__._,_.___
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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