The importance of minimum ventilation to heat requirement and housing temperature
During winter, the ventilation system works at a minimum level. The free heat production of the animals is not sufficient to make up for the heat loss created by the ventilation for which reason it is imperative to supply heat in order to keep the temperature at an acceptable level.

Normally, the minimum level of ventilation is determined by both the H2O production incl. evaporation from the wet surfaces and the CO2 production in the livestock house. Therefore, the required level of % RH (relative humidity) and CO2 will have a direct impact on the heat consumption in the livestock house. The thumb rule says that when the set point humidity level (% RH) is lowered from e.g. 75% to 65%, the heat requirement is doubled to maintain the set point temperature.
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