— reviewed against the regs as they stand.
How it works
A weather compensator uses an external temperature sensor to modulate the heating flow temperature: bitter outside, hotter radiators; mild outside, cooler ones. Instead of cycling on and off at a fixed high temperature, the system runs longer, lower and steadier — keeping a condensing boiler in its efficient condensing range far more of the time, and keeping homes more evenly comfortable.
For heat pumps, weather compensation is essentially native: lower flow temperatures directly raise the SCOP, which is why almost every heat pump runs on a compensation curve.
In the SAP calculation
Heating controls carry real weight in SAP. Weather compensation (and load compensation, its indoor-sensing cousin) improves the modelled efficiency of the heating system, nudging the DER down for very little hardware cost — many boilers only need the sensor and a setting enabled. Modern boiler-interlock, time and zone control requirements still apply alongside.
It’s the kind of cheap specification line that’s easy to forget and annoying to miss when a SAP calculation is marginal. We’ll flag it when it helps. Ask us.