A nodal model has been developed to represent room heat transfer in displacement ventilation and chilled ceiling systems. The model uses precalculated air flow rates to predict the air temperature distribution and the division of the cooling load between the ventilation air and the chilled ceiling. The air movements in the plumes and the rest of the room are represented separately using a network of ten air nodes. The values of the capacity rate parameters are calculated by solving the heat and mass balance equations for each node using measured temperatures as inputs. Correlations between parameter values for a range of cooling loads and supply air flow rates are presented.

}, keywords = {Chilled ceilings, commercial buildings, Displacement ventilation, energy, Heat Transfer, Nodal model, simulation}, doi = {10.1016/S0360-1323(00)00067-6}, url = {http://www.ibpsa.org/proceedings/BS1999/BS99_D-05.pdf}, author = {Simon J. Rees and Philip Haves} } @article {307, title = {Numerical Investigation of Transient Buoyant Flow in a Room with a Displacement Ventilation and Chilled Ceiling System}, journal = {International Journal of Heat and Mass Transfer}, volume = {44}, year = {2001}, month = {08/2001}, pages = {3067-3080}, chapter = {3067}, abstract = {The air flow in the office ventilation system known as displacement ventilation is dominated by a gravity current from the inlet and buoyant plumes above internal heat sources. Calculations of the flow and heat transfer in a typical office room have been made for this type of ventilation system used in conjunction with chilled ceiling panels. These calculations have been made in parallel with full size test chamber experiments. It has been found that with higher values of internal load (45 and 72 W m^{-2} of floor area) the flow becomes quasi-periodic in nature. Complex lateral oscillations are seen in the plumes above the heat sources which impinge on the ceiling and induce significant recirculating flows in the room. The frequency spectra of the transient calculations show good agreement with those of the experimental results. Comparison is also made between calculated mean room air speeds and temperature profiles and measured values.

A nodal model has been developed to represent room heat transfer in displacement ventilation and chilled ceiling systems. The model uses precalculated air flow rates to predict the air temperature distribution and the division of the cooling load between the ventilation air and the chilled ceiling. The air movements in the plumes and the rest of the room are rep- resented separately using a network of ten air nodes. The values of the capacity rate parameters are calculated by solving the heat and mass balance equations for each node using measured temperatures as inputs. Correlations between parameter values for a range of cooling loads and supply air flow rates are presented.

}, url = {http://www.ibpsa.org/proceedings/BS1999/BS99_D-05.pdf}, author = {Simon J. Rees and Philip Haves} }