Reset Ratio Formula; Reset Ratio Application Suggested Startup Settings - Watts AERCO Edge [ii] Operation Manual

Edge [ii] Controller Operation Manual
Appendix A: Indoor/Outdoor Reset Ratio

Reset Ratio Formula

Calculate Set point based on Outdoor temperature:
Water Temp Current =
(Outdoor Current - Outdoor P1) x (Water SP Temp P1 - Water SP Temp P2) + Water Temp P1
EXAMPLE:
What is the Current Water SP Temp when Outdoor Current is 30 °F?
Water Temp Current = (30 – 60) x (100 – 185) + 100 = -30/70 x -85 + 100 = 136.4 °F

Reset Ratio Application Suggested Startup Settings

Application
Radiators / baseboard
Radiant (High mass (Concrete)
Radiant (Low mass (Joists)
Air handler
Fan Coil
•
OMM-139_E 8/25/2020
(Outdoor P1 - Outdoor P2)
(60 – (-10))
P1
Outdoor
70
70
70
70
70
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
P1 P2
Water SP Outdoor
100 -20
90 -20
90 -20
90 -20
90 -20
P2 Warm Weather
Water SP Shutdown
190 65
140 65
120 65
140 65
140 65
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