HWReset

Brief Description

Hot water supply water temperature reset

Detailed Description

Hot-water systems with a design capacity exceeding 300,000 btu/h supplying heated water to comfort conditioning systems shall include controls that automatically reset supply water temperatures by representative building loads (including return water temperature) or by outdoor air temperature. where ddc is used to control valves, the set point shall be reset based on valve positions until one valve is nearly wide open or setpoint limits of the system equipment or application have been reached. (case study)

Index Description

  • Section 6.5.4.4 in 90.1-2016

Datapoints Description

  • T_oa_db: OA dry-bulb temperature

  • T_oa_max: OA dry-bulb upper threshold

  • T_oa_min: OA dry-bulb lower threshold

  • T_hw: Hot water temp observed from the system node

  • m_hw: Hot water flow rate

  • T_hw_max_set: Hot water maximum temp setpoint

  • T_hw_min_set: Hot water minimum temp setpoint

Assertions Description

  • When m_hw > 0, T_hw <= T_hw_max_set and T_hw >= T_hw_min_set; When m_hw < 0, always pass

Type Verification Description

Rule-based

Assertions Type

Pass