Revision history [back]

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: For "For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: "For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: "For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: "For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: "For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?

I'm looking at using SetpointManager:WarmestTemperatureFlow with the FlowFirst option. (From the IO Reference: "For FlowFirst, the manager tries to find the lowest supply air flow rate that will satisfy all the zone cooling loads at the maximum setpoint temperature. If this flow is greater than the maximum, the flow is set to the maximum and the setpoint temperature is reduced to satisfy the cooling loads.")

There is an input field for Minimum Turndown Ratio. What can I do if the connected VAV boxes have various turndown ratios (rather than the same for all), or if the connected VAV box minimum flow ratios are scheduled rather than constant? Will this SPM work for these cases?

For example: if the SPM input Minimum Turndown Ratiois 0.2, and that flow rate is used to establish the supply air temp setpoint, but a connected VAV terminal minimum flow ratio is actually 0.3, then the zone may be overcooled.

Why doesn't the SPM get the minimum flow information from the connected VAV terminal objects?