A study of kitchen range exhaust systems

Discusses tests of wall-mounted overhead, island, and downdraught kitchen exhaust systems. Tests involved velocity profile (exhaust dust) measurement and included fan curve determinations. Units with large diameter fans had steeper fan curves. Overhead hoods generally have lower flow rates than downdraught ranges. Velocity field results show that velocity diminishes rapidly away from the hood. Potential flow modelling results for velocity contours agree with measurements. Flow visualization (fog flows) was used to study how captive efficiency can be improved. Addition of side baffles on to a wall mounted overhead exhaust hood provided the best capture of steam from boiling water in pans. Perimeter slots also helped. Downdraught units performed well on steam capture from low pans. Briefly considers sound measurements. (C.J.U.)