Exhaust heated heater for vehicle - has frost and overtemperature protection valves, and water additives are not required

摘要

The heat exchanger for a car heater has a tank (9) fitted with control valves to ensure that the tank temperature is kept within set limits, to prevent the tank from freezing or boiling. Water is heated by a separate heat exchanger (4) around the exhaust pipe. If the temperature in the tank falls below a set level than a safety valve drains all the water into the heat exchanger which is constructed to withstand freezing expansion. Also, if the water in the tank exceeds a set amount then the flow to the heat exchanger is limited and a venting valve (16) in the top of the tank allows over pressure to be vented. The system does not require anti-freeze additives.