| 摘要 |
<p>A heating and ventilating system especially for buildings such as churches which require infrequent, short term heating, comprises ducting 1 extending from an inlet 3 arranged to receive air from outside the building to an outlet 4 arranged to deliver air into the building. A fan 5 in the ducting supplies air to a burner 6 in the ducting which heats the air passing to the outlet via a sound attenuator 8. A control system regulates the heat output of the burner by reducing the fuel supply to the burner when the temperature is below a pre-set value, thereby reducing thermal shock caused by heating the building too rapidly. <IMAGE></p> |
