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Hi,

Being still a novice in Openstudio I do not know how to properly design HVAC systems. therefore I need help to correctly design one.

For the moment I am using PTAC DX Clg Elec Htg, in reality my AC has no heating. I have hard sized most of the parameters, namely:

OS:ZOneHVAC:PackagedTerminalAirConditioner

• Supply Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Supply Air Flow Rate During Heating Operation: ~ 0 (because no heating)
• Supply Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)
• Outdoor Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Outdoor Air Flow Rate During Heating Operation: 0 (because no heating)
• Outdoor Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)

OS:Coil:Heating:Electric

• Nominal Capacity: 0 (because no heating)

OS:Fan:ConstantVolume

• Maximum Flow Rate: 0.431 m^3/s (I had to hard size this because every time I ran the simulation it couldn't autosize because there was No "Zone:Sizing" objects even though I had set the Do Zone Sizing Calculation and Do System Sizing Calculation to on in Simulation Control, it works when hard sized)

OS:Coil:Cooling:DX:Single:Speed

• Rated Total Cooling Capacity: 10550 W
• Rated Sensible Heat Ratio: 0.7 (had to hard size, same reason explaine in OS:Fan:ConstantVolume)
• Rated COP 2.8

The rest was left alone.

When I run the simulation with the above parameters it is able to complete, however when I look at HVAC load I have this (0 cooling load).

I've left the Cooling Sizing Parameters and Heating Sizing Parameters to their default values and have not done any design days, I have only used the weather file from the NREL website. I have however made my own Availability Schedule For OS:ZOneHVAC:PackagedTerminalAirConditioner, it is an OnOff Schedule type and looks like this:

However the other Schedules have been left as there default schedule namely:

• Supply Air Fan Operating Mode Schedule for OS:ZOneHVAC:PackagedTerminalAirConditioner: Always On Discrete 17
• Availability Schdule for OS:Coil:Heating:Electric: Always On Discrete 19
• Availability Schdule for OS:Fan:ConstantVolume: Always On Discrete 18

And therefore there isn't any electrical consumption from the PTAC

Any Help Would be greatly appreciated.

Hi,

Being still a novice in Openstudio I do not know how to properly design HVAC systems. therefore I need help to correctly design one.

For the moment I am using PTAC DX Clg Elec Htg, in reality my AC has no heating. I have hard sized most of the parameters, namely:

OS:ZOneHVAC:PackagedTerminalAirConditioner

• Supply Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Supply Air Flow Rate During Heating Operation: ~ 0 (because no heating)
• Supply Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)
• Outdoor Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Outdoor Air Flow Rate During Heating Operation: 0 (because no heating)
• Outdoor Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)

OS:Coil:Heating:Electric

• Nominal Capacity: 0 (because no heating)

OS:Fan:ConstantVolume

• Maximum Flow Rate: 0.431 m^3/s (I had to hard size this because every time I ran the simulation it couldn't autosize because there was No "Zone:Sizing" objects even though I had set the Do Zone Sizing Calculation and Do System Sizing Calculation to on in Simulation Control, it works when hard sized)

OS:Coil:Cooling:DX:Single:Speed

• Rated Total Cooling Capacity: 10550 W
• Rated Sensible Heat Ratio: 0.7 (had to hard size, same reason explaine in OS:Fan:ConstantVolume)
• Rated COP 2.8

The rest was left alone.

When I run the simulation with the above parameters it is able to complete, however when I look at HVAC load I have this (0 cooling load).

I've left the Cooling Sizing Parameters and Heating Sizing Parameters to their default values and have not done any design days, I have only used the weather file from the NREL website. I have however made my own Availability Schedule For OS:ZOneHVAC:PackagedTerminalAirConditioner, it is an OnOff Schedule type and looks like this:

However the other Schedules have been left as there default schedule namely:

• Supply Air Fan Operating Mode Schedule for OS:ZOneHVAC:PackagedTerminalAirConditioner: Always On Discrete 17
• Availability Schdule for OS:Coil:Heating:Electric: Always On Discrete 19
• Availability Schdule for OS:Fan:ConstantVolume: Always On Discrete 18

And therefore there isn't any electrical consumption from the PTAC

Any Help Would help on how to correctly design this type of HVAC system to get cooling loads and electrical consumption be greatly appreciated.

Hi,

Being still a novice in Openstudio I do not know how to properly design HVAC systems. therefore I need help to correctly design one.

For the moment I am using PTAC DX Clg Elec Htg, in reality my AC has no heating. I have hard sized most of the parameters, namely:

OS:ZOneHVAC:PackagedTerminalAirConditioner

• Supply Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Supply Air Flow Rate During Heating Operation: ~ 0 (because no heating)
• Supply Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)
• Outdoor Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Outdoor Air Flow Rate During Heating Operation: 0 (because no heating)
• Outdoor Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)

OS:Coil:Heating:Electric

• Nominal Capacity: 0 (because no heating)

OS:Fan:ConstantVolume

• Maximum Flow Rate: 0.431 m^3/s (I had to hard size this because every time I ran the simulation it couldn't autosize because there was No "Zone:Sizing" objects even though I had set the Do Zone Sizing Calculation and Do System Sizing Calculation to on in Simulation Control, it works when hard sized)

OS:Coil:Cooling:DX:Single:Speed

• Rated Total Cooling Capacity: 10550 W
• Rated Sensible Heat Ratio: 0.7 (had to hard size, same reason explaine in OS:Fan:ConstantVolume)
• Rated COP 2.8

The rest was left alone.

When I run the simulation with the above parameters it is able to complete, however when I look at HVAC load I have this (0 cooling load).

I've left the Cooling Sizing Parameters and Heating Sizing Parameters to their default values and have not done any design days, I have only used the weather file from the NREL website. I have however made my own Availability Schedule For OS:ZOneHVAC:PackagedTerminalAirConditioner, it is an OnOff Schedule type and looks like this:

However the other Schedules have been left as there default schedule namely:

• Supply Air Fan Operating Mode Schedule for OS:ZOneHVAC:PackagedTerminalAirConditioner: Always On Discrete 17
• Availability Schdule for OS:Coil:Heating:Electric: Always On Discrete 19
• Availability Schdule for OS:Fan:ConstantVolume: Always On Discrete 18

And therefore there isn't any electrical consumption from the PTAC

Any help on how to correctly design this type of HVAC system to get cooling loads and electrical consumption would be greatly appreciated.

Hi,

Being still a novice in Openstudio I do not know how to properly design HVAC systems. therefore I need help to correctly design one.

For the moment I am using PTAC DX Clg Elec Htg, in reality my AC has no heating. I have hard sized most of the parameters, namely:

OS:ZOneHVAC:PackagedTerminalAirConditioner

• Supply Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Supply Air Flow Rate During Heating Operation: ~ 0 (because no heating)
• Supply Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)
• Outdoor Air Flow Rate During Cooling Operation: 0.431 m^3/s
• Outdoor Air Flow Rate During Heating Operation: 0 (because no heating)
• Outdoor Air Flow Rate When No Cooling or heating is Needed: 0 (because in reality the coils are always on when the fan is on, it's in Thailand so it is very hot and humid --> AC is working hard)

OS:Coil:Heating:Electric

• Nominal Capacity: 0 (because no heating)

OS:Fan:ConstantVolume

• Maximum Flow Rate: 0.431 m^3/s (I had to hard size this because every time I ran the simulation it couldn't autosize because there was No "Zone:Sizing" objects even though I had set the Do Zone Sizing Calculation and Do System Sizing Calculation to on in Simulation Control, it works when hard sized)

OS:Coil:Cooling:DX:Single:Speed

• Rated Total Cooling Capacity: 10550 W
• Rated Sensible Heat Ratio: 0.7 (had to hard size, same reason explaine in OS:Fan:ConstantVolume)
• Rated COP 2.8

The rest was left alone.

When I run the simulation with the above parameters it is able to complete, however when I look at HVAC load I have this (0 cooling load).

I've left the Cooling Sizing Parameters and Heating Sizing Parameters to their default values and have not done any design days, I have only used the weather file from the NREL website. I have however made my own Availability Schedule For OS:ZOneHVAC:PackagedTerminalAirConditioner, it is an OnOff Schedule type and looks like this:

However the other Schedules have been left as there default schedule namely:

• Supply Air Fan Operating Mode Schedule for OS:ZOneHVAC:PackagedTerminalAirConditioner: Always On Discrete 17
• Availability Schdule for OS:Coil:Heating:Electric: Always On Discrete 19
• Availability Schdule for OS:Fan:ConstantVolume: Always On Discrete 18

And therefore there isn't any electrical consumption from the PTAC

Any help on how to correctly design this type of HVAC system to get cooling loads and electrical consumption would be greatly appreciated.