Run the 5ZoneVAV-Pri-SecLoop.idf as it is, but modify the report variables to what were used in my previous IDF, and add the diagnostics and display of schedules values.
The model.zip in the macro posting is this example in the MACRO format without using the definition files.
This model still have the reheat in the zones, but uses water for both heating and cooling. It is relatively simple to remove the reheat coils.
My recent posting on MACRO usage was actually preparing to help you expand the current IDF for the larger building. I did mention that in my posting.
Chinese has a four word proverb, 'study old discover new'. What it really meant is to study the old working model, then you will understand and discover new features.
When you read the I/O manual, you are reading the components in isolation. When you run an example file, it has all the components working together.
You can then make changes and observe the effect.
I posted a chart to illustrate the control of the set point temperature. Plenum temperature is tested at the mixedAir node to determine whether heating or cooling is needed. In my chart, the Summer condition was correct, although the setting was too low, therefore most of the dampers were closed.
In Winter, the neutral temperature values were all above 10°C. Therefore the heating never active. So the solution is to move both the setpoint temperature higher to 23°C and 21°C.
===================
If you send me the large building geometry, and the way you wanted to implement the HVAC, I shall try to set up a simple basic system.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: n_junk@xxxxxxxxxxxxxx
Date: Fri, 22 Jul 2011 22:43:05 +0000
Subject: [EnergyPlus_Support] Re: Problem with removing reheat coils in VAV
Hi,
In these days I have studied with careful the HVAC system I have to model in my thesis and for the problems I had with my file.
At this point I finally can mantain the zones' temperatures between 20-25ºC has I wanted. What I did was to remove some autosize fields and insert there the values I have in reality, and force the VAV damper to be always fully opened (which is the situation I have in reality). I also forced the system to insert in the zones the outdoor air I need.
The point that Dr. Li made about the internal loads made me understand better the problems I have. Both suggested programs were also useful, many thanks to you all!
I still have one big problem though. I'm currently using an Electric Heating Coil in each RTU, but I really need to use a Hot Water Coil and a Boiler. The problem is that when I switch from the electric to hot water coil the zones' temperatures drop below the setpoint and thermostat value (below 20ºC). More strange than that is that the setpoints are all the same, I only changed the coil type and add a hotwater loop and a boiler, but the outlet temperatures from the system drop a lot. If I rise the heating design temperature, the autosize feature increases the estimated heating coil capacity but the temperatures doesn't change at all... Do you know what's going on?
Note that this time I'm only using the HVACTemplates. To emulate the problem just open a example file with packagedVAV and just change the gas or electric heating coil for one with water.
If everything else fails (I'm running out of time), is there any known ratio between a electric coil's and a equivalent hot water coil's capacity? Like, for a same design heating temperature, a electric coil with x capacity is equivalent to a water coil with x/y capacity?
Once again many thanks to you all for all the precious help!
__._,_.___
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.
![]()
__,_._,___
The model.zip in the macro posting is this example in the MACRO format without using the definition files.
This model still have the reheat in the zones, but uses water for both heating and cooling. It is relatively simple to remove the reheat coils.
My recent posting on MACRO usage was actually preparing to help you expand the current IDF for the larger building. I did mention that in my posting.
Chinese has a four word proverb, 'study old discover new'. What it really meant is to study the old working model, then you will understand and discover new features.
When you read the I/O manual, you are reading the components in isolation. When you run an example file, it has all the components working together.
You can then make changes and observe the effect.
I posted a chart to illustrate the control of the set point temperature. Plenum temperature is tested at the mixedAir node to determine whether heating or cooling is needed. In my chart, the Summer condition was correct, although the setting was too low, therefore most of the dampers were closed.
In Winter, the neutral temperature values were all above 10°C. Therefore the heating never active. So the solution is to move both the setpoint temperature higher to 23°C and 21°C.
===================
If you send me the large building geometry, and the way you wanted to implement the HVAC, I shall try to set up a simple basic system.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: n_junk@xxxxxxxxxxxxxx
Date: Fri, 22 Jul 2011 22:43:05 +0000
Subject: [EnergyPlus_Support] Re: Problem with removing reheat coils in VAV
Hi,
In these days I have studied with careful the HVAC system I have to model in my thesis and for the problems I had with my file.
At this point I finally can mantain the zones' temperatures between 20-25ºC has I wanted. What I did was to remove some autosize fields and insert there the values I have in reality, and force the VAV damper to be always fully opened (which is the situation I have in reality). I also forced the system to insert in the zones the outdoor air I need.
The point that Dr. Li made about the internal loads made me understand better the problems I have. Both suggested programs were also useful, many thanks to you all!
I still have one big problem though. I'm currently using an Electric Heating Coil in each RTU, but I really need to use a Hot Water Coil and a Boiler. The problem is that when I switch from the electric to hot water coil the zones' temperatures drop below the setpoint and thermostat value (below 20ºC). More strange than that is that the setpoints are all the same, I only changed the coil type and add a hotwater loop and a boiler, but the outlet temperatures from the system drop a lot. If I rise the heating design temperature, the autosize feature increases the estimated heating coil capacity but the temperatures doesn't change at all... Do you know what's going on?
Note that this time I'm only using the HVACTemplates. To emulate the problem just open a example file with packagedVAV and just change the gas or electric heating coil for one with water.
If everything else fails (I'm running out of time), is there any known ratio between a electric coil's and a equivalent hot water coil's capacity? Like, for a same design heating temperature, a electric coil with x capacity is equivalent to a water coil with x/y capacity?
Once again many thanks to you all for all the precious help!
__._,_.___
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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__,_._,___