Commendation for police HQ fitness facility

Commendation for police HQ fitness facility

Commendation for police HQ fitness facility

Keywords Energy, Heating/ventilation, Plant efficiency

By applying heat pump technology with ventilation heat recovery, a new fitness room built at Northamptonshire Police Headquarters gained an excellent environmental system, which is economical in both running costs and capital outlay. The system was commended in the recently-held East Midlands Electricity Business Energy Awards.

Constructed as a 120m² annexe to the Wootton Hall headquarters building, the fitness and training room shares the site with a boiler house which serves the main office block. A wet radiator system was initially a heating option, as it would have been quite possible to connect to the existing boiler plant.

In producing a building services design, Northamptonshire County Council Property Services' Eamonn Byrne realised there were problems with this approach, owing to the inconsistent heating requirements of the site as a whole.

Although the office block is unoccupied overnight, the new fitness room is a 24-hour facility, as police staff operate around the clock. It would have been extremely inefficient to operate the large boiler plant at night and weekends in order to deliver heating to a small, distant branch of the system.

With up to 18 occupants using the exercise equipment at any time, in a building with excellent insulation standards and draught protection, mechanical ventilation was another essential requirement.

Mr Byrne also knew that some comfort cooling would be needed. Figures produced by East Midlands Electricity predicted regular cooling loads for the fitness room.

An all-encompassing solution to the problems of heating, cooling and ventilating the room was found by specifying electric heat pumps and ventilation heat recovery, together with simple but effective controls. This option had the additional benefit of avoiding any intrusive pipework or radiators.

Two Daikin air-to-air heat pumps were installed, to work in tandem, together with a passive heat recuperator. The controls were configured such that maximum use is made of fan-only free cooling, or free heating recovered from the recuperator. When additional cooling or heating is required, the reversible heat pumps introduce either cool air or warm air to the space through ceiling cassettes.

In cooling mode, the heat pump evaporator coils in the ceiling cassettes condense moisture from the re-circulated air, which also loses a quantity of heat to the extract air at the recuperator. The result combines efficient cooling with a comfortable atmosphere, allowing perspiration to evaporate normally during exercise.

As the heat pumps act directly on the room air, they respond rapidly to variations in room temperature as the number of occupants changes. They also quickly achieve set point from switch-on, a factor which has influenced the control approach.

The whole heating, cooling and ventilation system, along with the lighting, is controlled by a passive infra-red sensor to prevent energy being wasted when the room is unoccupied. However, the room conditions may also be adjusted at a remote controller on the wall and the heat pumps maintain a minimum set-back temperature to ensure the room never gets too cold.

Capital costs for the whole installation are lower than those of a wet radiator heating system with mechanical ventilation, particularly as long pipework runs would have been necessary to connect to the boiler plant. As the services are all-electric, it was possible to let all the works to a single contractor, a factor that contributed to the mechanical and electrical system showing significant savings against the original budget.

In terms of energy costs, the ability of the heat pumps to provide cooling and dehumidification, as well as heating, adds only a calculated £52 per annum to the energy bill. Even with the extra capability, the system has a lower environmental cost in estimated CO₂ emissions than the central heating option.

The East Midlands Electricity Business Energy Awards is an annual competition, which aims to give recognition to those organisations in the East Midlands region which have used electrical techniques to gain commercial or environmental advantage, or to improve business performance.

For further information contact: Mike Newell, Sales and Marketing, East Midlands Electricity, Woolsthorpe Close, Bilborough, Nottingham NG8 3JP.