Warm air heating with a constant high supply air flow rate without recirculation.

In Halmstad a multi-apartment house has been built with air carried heating. Fresh air was used as the only heat carrier. To improve the air quality it was decided not to use circulation flow, which is normally required for air carried heating. Theheating requirement was obtained with a higher air flow than what the standard requires. This also implied improved air quality. The standard specification states 0.5 changes per hour as the minimum requirement, but in Halmstad the house was ventilated with 0.7 - 1.0 changes per hour. The drawbacks resulting from this (greater ventilation losses, with operating faults to fans) have been solved with a high degree of heat recovery and frequency control of the fans.