Performance of Chilled Beam with Radial Swirl Jet and Diffuse Ceiling Air Supply in Heating Mode

The performance of diffuse ceiling air supply and chilled beam with swirl jet (CSW) in heating mode (winter situation) was studied and compared with regard to the generated indoor environment. An office mock-up with one occupant was simulated in a test room (4.5 x 3.95 x 3.5 m3 (L x W x H)). A window (6.5 m2) with cold surface (14 °C) was simulated by radiant panels. Four CSW chilled beam units were installed symmetrically on the suspended ceiling together with two exhaust vents. The diffuse ceiling inlet was made of standard perforated acoustic tiles (0.5% total degree of perforation). The room air temperature was kept at 21 °C. Tracer gas was used to simulate pollution from floor and desk. The experimental conditions comprised: 1) night time without heat sources in the room; the room air conditioning system was used to heat up the room; 2) heat load generated by an occupant (simulated by dressed thermal manikin) and a laptop; 3) heating by convectors positioned under the window (convectors used alone and convector used together with CSW supplying isothermal air for ventilation). The heat distribution provided by the systems was not effective compare to the distribution provided by convector. The tracer gas concentration in the occupied zone was considerably higher than the concentration at the exhaust. Airflow rate considerably higher (2.5–5.9 times higher) than the minimum ventilation rate required in the standards was needed to safeguard the indoor air quality.