Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

How to turn the radiators off? Do you know how it is done? You were only simulating during the Winter months of the weather file.

my problem is that : the boiler is not controlled by zone heating setpoint , but controlled only with its hot water temperature tank , it means boiler will be off when its hot water temperature is 80 C how ever zone air temperature is out of heating setpoint

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Thursday, February 16, 2012 10:36 PM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

You are using the same boiler for radiator and DHW. Therefore, the boiler should be on all the time.

The radiators are controlled by the zone thermostat. If you make the heating only available using the Type 1 thermostat in Winter, the radiators will be turned on in Winter.
In the thermostat type schedule, set type 1 for Winter and type 2 for Summer, if you want cooling in Sommer. Type 0 means no equipment.

Type 4 will use two set point schedules with a dead band between them. This will cover the change over periods, and is best for your location, as the boiler is on all the time.

The cooling schedule can control the ventilation or to add cooling.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Wed, 15 Feb 2012 23:40:20 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dear Dr.Li

thankd for your answering ,

yes i undrestand about bypass pump , thanks for your useful describing , but i dont undrestand how loop temperature setpoint control the loop? nad how i can control burner of boiler for example turn on the burner of boiler when ever outlet temperature of water from boiler is greater than 80C , and turn of the nutural gas flow of burner boiler when ever outler temperature of water from boiler is less than 75C?

How to turn the radiators off? Do you know how it is done? You were only simulating during the Winter months of the weather file.

Choose the correct thermostat type, in the mail above.

i use Availability Schedule for radiators that radiator will be off in summer :

winteron,                !- Name
    Any Number,              !- Schedule Type Limits Name
    Through: 3/31,           !- Field 1
    for:alldays,             !- Field 2
    until: 24:00, 1,         !- Field 4
    through: 9/30,           !- Field 5
    for: alldays,            !- Field 6
    until: 24:00, 0,         !- Field 8
    through: 12/31,          !- Field 9
    for: alldays,            !- Field 10
    until: 24:00, 1;         !- Field 12

but i have problem i dont know when energyplus turn on/off the boiler ?

i want to off the natural gas of burner of boiler when its outler water temperature from the boiler is greater than 80C, and on the boiler when outler temperature less that 75C (5C is deadband )

if outler water temperature of boiler > 80 then off the burner of boiler

and when outler water temperature of boiler < 75 then on the burner of boiler , i dont know how i can control the burner of boiler like that ?!

This is already done, according to what you described.

Dr.Li could you please desribe it for me how setpoint temperature control the plant?

when i run the idf for sizingperiod day i see in variable output file excel winter design day is repeated for 6-7 times like below :

i dont undrestant this repeat? is this warm up? it repeats until convergence reaches? The following is the 10min time interval result, when the timestep is set to 6. They are not warmup repeats.

Because you do not display the variables in timestep, therefore nothing is displayed. In fact, I never look at the monthly results.

01/15 00:10:00 Month/ Day Hour:min:sec format.

01/15 00:20:00

01/15 00:30:00

01/15 00:40:00

01/15 00:50:00

.......

01/15 24:00:00 This is a repeat and not a repet, if you run DesignDay and

Weatherfile of the same date.

01/15 00:10:00

01/15 00:20:00

01/15 00:30:00

01/15 00:40:00

01/15 00:50:00

.......

01/15 24:00:00

thanks Dr.Li ,

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Wednesday, February 15, 2012 9:23 PM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Simulation will do whatever you ask the program to do.

It is not necessary to provide a by-pass. You can use a pump which has a low head to simulate the natural flow.

You can look at the .rdd and see what is available. If there is a flow rate through the bypass in the output variable, you can monitor that.

If a branch or component has an available schedule, it can be scheduled. Scheduling need not be automatic. If your caretaker turns on and off the pump manually every morning after starting the furnace, you will schedule both these activities.

The house hold thermostat has mercury switch module with two contacts mounted on a temperature sensing element. There is also a fan speed control (off, 1,2,3), heat/cool control, and a thermometer. All these are simulated separately, as sensor, controller or actuator, and selectors.
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You can use the pump mass flow rate variable to show that the pump is working. This is monitoring process. Scheduling is a control process. Sense and then actuate is a controller manager action.

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If your are worried about the power consumption, simply reduce the head. The circulation pump is not a large element, unless you need to lift the water to a very high level into an open tank.

When all the radiators are turned off in Summer, the pump will only pumping the DHW heater. You can sense the DHW temperature and force the pump on again, if necessary.

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How to turn the radiators off? Do you know how it is done? You were only simulating during the Winter months of the weather file.

my problem is that : the boiler is not controlled by zone heating setpoint , but controlled only with hot water temperature , it means boiler will be off when outlet temperature is 80 C how ever zone air temperature is out of heating setpoint
Dr. Li