Variable Displacement by Waterloo & Swegon
Waterloo have strengthened their product offering by replacing their displacement range with the full portfolio of Swegon displacement products. By integrating diffusion systems from the Swegon group, the supplier of air terminal devices can deliver the strongest range of room unit products in the UK market.
In large spaces such as airports, theatres, factory floors, open offices and supermarkets where a traditional mixed system can fall short, using a displacement system can have significant advantages on indoor air quality & efficiency.
Working on the principles of buoyancy & stratification, air is effectively supplied at low velocity to involve minimal mixing. Supplying air below room temperature (typically -3K to -6K) allows cool air to travel along the floor in a thin layer typically less than 200mm high. When the cool air meets a heat source such as a person or piece of equipment, a portion of the conditioned air is captured by the thermal plume of the heat source, while the remainder of air continues further into the room.
As displacement utilises buoyancy forces, the density differences in the air form two zones in the space: an upper zone with old polluted air and a lower zone of new clean air. By so doing, airborne pollutants lighter than air rise above the breathing zone meaning the air quality in the occupied zone is generally superior to that achieved with mixing ventilation.
Displacement systems can present many potential opportunities for energy saving:
- The higher the space the greater the payback. As consideration for cooling the whole space is not required. Added to the lower pressure drop associated with displacement ventilation terminals selection of smaller & slower fans is possible for a reduction in fan energy.
- The supply air temperature is higher for displacement systems (circa 18°C) than for an overhead mixing systems (circa 14°C) meaning we have greater access to free cooling throughout the year thus improving chiller efficiency.
Waterloo have introduced 11 models, the majority of the which are complete with Swegon’s Varizon® system which offers one of the best user comfort at close range on the market. The terminal can be set to move the near zone away from critical areas reducing the risk of drafts. This can be particularly effective in conference rooms with high occupancy & minimal space.
The nozzles can also be readjusted after commissioning in instances of office restructure & occupant relocation.
The displacement terminals have a full complement of test data in strict accordance to the British & European Standard BS -EN 12239 and a full suite of support material.