Hot Water Reset Schedule Calculator

Calculate outdoor air reset schedule for hot water heating systems.

Coldest expected outdoor temperature.
°F
OAT where heating is no longer needed (typically 60-65°F).
°F
Hot water supply temp at design conditions.
°F
Minimum HW supply temp at balance point.
°F

Results

Reset Ratio-°F HW / °F OA
HW Temp at 30°F OAT-°F
HW Temp at 50°F OAT-°F
References: ASHRAE Handbook - HVAC Systems and Equipment, Chapter 13. Outdoor air reset strategies for optimal efficiency.