Home and Building, Volume 18 Number 1 (June 1955)
Heating with steam is not normally used in homes in N.Z. today although it is still used quite extensively in industry. With steam, convectors are usually used for heating offices, etc., while unit heaters or projection heaters are used for heating large spaces such as workshops, factories, etc. The unit heater or the projection heater is a battery of finned coils encased in a sheet metal casing and fitted with a motor driven propellor fan which forces the circulation of air through the fins and distributes the air in the building.