The power of the heating and cooling coils would must be affected by the power of the stream redstone. For exemple, a hanting coil recevied a stream of redstone of power 5, so the temperature emited by heating coil will must be of +10.

There, the ladder of temperature would of 0 to +30. And +1 of power of stream of redstone do +2 of temperature.

Idem for the cooling coils, but the temperature change would of 0 to -30