Vertical Temperature Gradients In Apartments With Hydronic Radiator Heating

A vertical temperature stratification normally exists in rooms during the heating season in cold climates. An expression of the gradient in apartments heated by hydronic radiator heating systems with exhaust ventilation has earlier been developed assuming a dependency of the outdoor temperature. The expression was used by a public real estate owner when re-calculating measured indoor temperature at 2.1 m above floor to 1.2 m above floor representing the occupancy zone and used for individual metering and billing of space heating cost. To validate the suggested expression temperature measurements have been made at four heights in living rooms in apartments built in the 70's. The heights includes 0.0, 0.1, 1.1 and 1.7 m above floor. The theoretical expression has been compared to the full-scale measurements and in general the expression overestimates the vertical temperature gradient. The measured gradients are generally very low. The thermal comfort in the aspect of vertical temperature gradient is good for the studied period.