Heat recovery in natural ventilation design of office buildings.

Heat recovery in ventilation systems for office buildings in cold climates is necessary for tworeasons:1. To obtain acceptable indoor thermal comfort by preheating of fresh air,2. To reduce ventilation energy lossThis paper describes a pilot system built in the laboratory of the Norwegian Building ResearchInstitute, NBI, based upon the concept of an advanced fan assisted natural ventilation systemwith heat recovery. The concept was developed by NBI. The objective of making the pilot systemwas to find out how a real system based upon this concept works and to supply the NatVentproject with measuring data both from a winter period and a summer period. The concept is newand is not yet tested in a real office type building.This paper gives a brief description of the components and the system. The paper also summarisesthe measurements of the resistance in the system, the driving forces, the temperatures and theairflow.