Re: [EnergyPlus_Support] Re: Eplus

Hi Jean,

Thanks for your all helps and your patience. I did your all suggestions in my simulation. However, the problem goes on. I mean, heating coils go on working during summer. Although, the room setpoint temperature is 22 C, the room temperature is set to 25 C in heating season. Therefore, the electric consumption for heating increses too much. I send the *.idf file of final case as "GB deneme 13".

In previous case, I removed the "SetpointManager:SingleZone:Cooling" and run the simulation. In this case cooling consumption increases a little but heating consumption decreases too much. However, for example, the reheat coil in PIU heats the cool air (19 C) to 22 C in cooling season. Therefore, chiller and cooling coils consume electric too much. Also I send the *.idf file of previous case as "GB deneme 12".

If I can't solve the problem I decide the create the seasonal schedule for heating coils, cooling coils and chiller in order to work at right seasons.

Best regards

Alpay Akguc

From: Jean Marais <jeannieboef@xxxxxxxxx>
To: Ayzer Akguc <alpayakguc@xxxxxxxxx>
Sent: Tuesday, July 10, 2012 3:41 PM
Subject: Re: [EnergyPlus_Support] Re: Eplus

Sorry, I was sleeping...ofcourse I meant for the heating.

SetpointManager:SingleZone:Heating,
    Zemin Heating SPM,       !- Name
    Temperature,             !- Control Variable
    14,                      !- Minimum Supply Air Temperature {C}
    33,                      !- Maximum Supply Air Temperature {C}
    Zemin:BankaOfis,         !- Control Zone Name
    Zemin:BankaOfis Zone Air Node, !- Zone Node Name
    Zemin:BankaOfis Parallel PIU Supply Inlet, !- Zone Inlet Node Name
    Air Loop Zemin Htg Coils Node List; !- Setpoint Node or NodeList Name

Nodelist,
Air Loop Zemin Htg Coils Node List,
Air Loop Zemin AHU Heating Coil Air Outlet Node,
Kat%06:IslakHacim Parallel PIU Supply Inlet;

On 10 July 2012 13:13, Jean Marais <jeannieboef@xxxxxxxxx> wrote:

Wow. I did not see the reheating coil at the terminal unit. You'll need to try and place the same setpoint temperature here as you did in your AHU. I suggest you make a nodelist with the two nodes (the exit node of AHU heating coil and the exit node of the reheating coil) and point your setpoint manager to the nodelist, e.g.

SetpointManager:SingleZone:
Cooling,
    Zemin Cooling SPM,       !- Name
    Temperature,             !- Control Variable
    14,                      !- Minimum Supply Air Temperature {C}
    33,                      !- Maximum Supply Air Temperature {C}

    Zemin:BankaOfis,         !- Control Zone Name
    Zemin:BankaOfis Zone Air Node, !- Zone Node Name
    Zemin:BankaOfis Parallel PIU Supply Inlet, !- Zone Inlet Node Name
    Air Loop Zemin Htg Coils Node List; !- Setpoint Node or NodeList Name

Nodelist,
Air Loop Zemin Htg Coils Node List,
Air Loop Zemin Supply Side Outlet 1,
Kat%06:IslakHacim Parallel PIU Supply Inlet;

Try this for one zone and let me know the result.

On 10 July 2012 12:43, Ayzer Akguc <alpayakguc@xxxxxxxxx> wrote:

Hi Jean,

I run the simulation and take the result. In this case, the I saw that the setpoint temperature was set as reverse. I mean the room temperature is 25 at heating season and 22 at cooling season. However, setpoint temperatures are 22 at heating season and 25 at cooling season. Therefore heating coils works so much again due to this case. Besides, setpoint not mets for cooling became high at ground floor. I send you the *.csv file. How can I solve this problem ?

Best regards.

Alpay Akguc

From: Jean Marais <jeannieboef@xxxxxxxxx>
To: Ayzer Akguc <alpayakguc@xxxxxxxxx>

Sent: Tuesday, July 10, 2012 1:11 PM

Subject: Re: [EnergyPlus_Support] Re: Eplus

I just checked the io ref. They are the wrong way around. The first field is the minimum and should be 14 and the next is the max and should be 33. Try it, run it, and see if the results look good.

On 10 July 2012 12:04, Ayzer Akguc <alpayakguc@xxxxxxxxx> wrote:

Yes I relised it. I used suggested values for min. and max. supply air temperature. Have I any wrong about sequencing ? I mean that  min. supply air temperature = 33 C and max. supply air temperature = 14 C ?

Or should these values be different ?

Best regards.

Alpay AkgÃ¼Ã§

From: Jean Marais <jeannieboef@xxxxxxxxx>
To: Ayzer Akguc <alpayakguc@xxxxxxxxx>
Sent: Tuesday, July 10, 2012 12:29 PM
Subject: Re: [EnergyPlus_Support] Re: Eplus

SetpointManager:SingleZone:Cooling,
    Zemin Cooling SPM,       !- Name
    Temperature,             !- Control Variable
    33,                      !- Minimum Supply Air Temperature {C}
    14,                      !- Maximum Supply Air Temperature {C}
    Zemin:BankaOfis,         !- Control Zone Name
    Zemin:BankaOfis Zone Air Node, !- Zone Node Name
    Zemin:BankaOfis Parallel PIU Supply Inlet, !- Zone Inlet Node Name
    Air Loop Zemin Supply Side Outlet 1; !- Setpoint Node or NodeList Name

This seems the wrong way around.

On 10 July 2012 10:41, Ayzer Akguc <alpayakguc@xxxxxxxxx> wrote:

Dear Jean,

I did your all suggestions but the cooling coil works during the year and set the air temperature to 14 C. Therefore reheat coils works too much to set the room temperature to 22 C.

I have two predictions about this problem:

- If I am right, I need to use seasonal schedule for working of heating and cooling coils at right seasons. However, I think still that EnergyPlus can arrange the working of coils according to season without using seasonal schedule.

- I used outlet air node name of coils in setpoint node name at SetpointManager:SingleZone. May be these node names are different.

I sent you my *.idf file. Also I sent the *.csv file in which outlet air node temperatures of coils exist. (I am using EnergyPlus version 7.0)

I thank you due to your all helps.

Best regards.

Alpay Akguc

From: Jean marais <jeannieboef@xxxxxxxxx>
To: EnergyPlus_Support@xxxxxxxxxxxxxxx

Sent: Tuesday, July 10, 2012 10:01 AM
Subject: [EnergyPlus_Support] Re: Eplus

I would go on 33/14 for both. If you put a minimum of 22 for the heating coil, it looks at zone temp and air temp at coil inlet to try and maintain the node setpoint temp set by the manager. This means that if the zone is too hot (say 27 deg C) and needs cooling, and you have benificial cold outdoor air at say 16 deg, the heating coil will try to achieve 22 at its exit node to try and "cool" the zone down from 27 with a delivered air temp of 27. The heating coil doesn't know that there is a cooling coil in the system. It doesn't know there is an economizer or oda damper...it just tries to do its best to achieve the zone setpoint. If the best means it goes down as low as it is allowed to from your setpoint restriction, then that is what it does.

You may argue that the heating coil should not be operational during "cooling mode", but if it sees cold outdoor air at 16 deg incoming, it assumes that the net balance may need to be heated to achieve the room air temp of heating setpoint. It is also trying to be a little predictive. I'm not sure about this last paragraph, since I've not looked at the fortran code, but I've made some painfull experiences regarding this. The heating coil will maintain the min temp of 22 at outlet if you set it to that, regardless heating or cooling mode.