Upwards blowing air curtain includes usually a shaped inlet, a fan, an outlet duct, sound attenuators, an underground plenum and a nozzle. Warmed air or outdoor air is blown from the nozzle forming a jet which travels the width of the doorway and run into the upper edge of the doorway. Upwards blowing air curtains are normally used in doorways to protect workers and processes from cold outdoor air and to reduce energy and maintenance costs of the industrial buildings (1,3).

The heating, ventilating and air conditioning (HVAC) systems are a vital part of every home. These mechanical systems help control the indoor conditions you need for comfort, health and safety. How these mechanical systems interact with other appliances is critical in keeping your home's indoor environment healthy and safe.

This month the cost arid research departments of Mott Green Wdll and Davis Langdon & Everest examine the costs and specification of chilled ceilings and beams in collaboration with specialists Trox and Halton.