Mixing / Tempering Valve Blend Temperature
Blended delivery temperature, mix ratio, or hot flow for a tempering valve, with a scald-limit flag.
Example
You enter
- Mode find-blend
- Hot supply temp (°F) 140
- Cold supply temp (°F) 60
- Hot flow (gpm) 1
- Cold flow (gpm) 1
You get
- Blend temp (°F) 100
- Percent hot 50 %
Details, formula, and sources
T_blend = (Qh*Th + Qc*Tc)/(Qh+Qc); inverse hot fraction = (T_target - Tc)/(Th - Tc); hot:cold ratio = (T_target - Tc)/(Th - T_target).
First-principles mixing energy balance for blending hot and cold potable water; the delivery-temperature limits follow the ASSE 1017 (master tempering) and ASSE 1016/1070 (point-of-use scald-guard) device standards and the IPC/UPC scald provisions, by name.
Public first-principles energy balance. The listed mixing valve and the AHJ govern the installed setpoint.
Estimate. AHJ and licensed plumber / gas fitter govern. Verify against the IPC / IFGC edition adopted in your jurisdiction.
Field names used by the API: mode, hot_temp_F, cold_temp_F, hot_gpm, cold_gpm, blend_temp_F, percent_hot
- Same fluid hot and cold are the same fluid (water); the balance is by flow-weighted temperaturefirst principles