In this article we compare to ventilation strategies to heat a “passive house” office building using only the ventilation system. Two ventilation strategies with supply air temperature above and below the current room temperature were compared through a cross over experiment. A questionnaire was used to measure the perceived health and well being. Both strategies documented very good indoor climate with highly positive scores on the questionnaire. The strategy with supply air temperature above the room temperature resulted in a little better perceived health and well being compared to the other strategy.