New buildings improve air quality but can raise energy use

New buildings can provide better indoor air while using more energy than older ones, ERR reports. Ventilation systems and the need to meet indoor climate standards can increase electricity and heating costs.

A Tallinn resident who moved from an apartment in an older Lasnamäe block to a new development in Kopli was surprised to find the new home’s electricity bill was twice as high. Lääneranna municipality faced a similar surprise after replacing an old school building with a new one: the new Lääneranna Gymnasium’s electricity and heating costs have proved considerably higher.

Mayor Tarvi Sits said price increases accounted for part of the rise, but the main cause might be the new ventilation system. The old, deteriorated building had no such system, he said. The municipality plans to commission an energy audit to review the building’s systems and determine whether adjustments could help control costs.

Priit Valk, director of property management services at State Real Estate Ltd, said a new or renovated building can use more energy when ventilation is added to improve indoor conditions. Better air quality and temperatures can improve working conditions, he said, so energy use must be considered alongside the indoor climate.

Fresh air comes at a cost

Jarek Kurnitski, a professor at Tallinn University of Technology, said ventilation is particularly energy-intensive in schools. A small classroom can hold many pupils, and the air needs to be replaced five times an hour, he said. If an old school had no ventilation system, its electricity use would naturally have been much lower.

Kurnitski said a good indoor climate requires energy, but the system should also be designed efficiently. Where rooms are not in intensive use from morning to evening, demand-controlled ventilation could save half of the system’s electricity use, he said.