A 22kW variable speed drive from ABB is helping staff keep their cool at the Football Association’s headquarters in London. By varying the speed of the building’s air handling fan to match the changing pressure in the air ducts precisely, the drive is also helping the FA save energy.
The drive, supplied by ABB HVAC partner DH Drives via air movement equipment manufacturer Fläkt Woods, was part of a wider upgrade of the Soho Square building’s systems. This was spurred by the need to include humidification in the air conditioning system for the first time. Building engineer David Bane explains: ‘Without humidification the relative humidity of the air was dropping below healthy levels, especially in the winter. Now the upgraded system is saving energy and is making everyone feel more comfortable.’
The air in the building is filtered and the pressure drop across the filters changes as they gradually become clogged with dust. In the old system, the air handling unit constantly pushed air through the ducts as if it was working against the maximum back pressure from the filters. ‘We used to use loads more energy and we’d also find unstable pressure conditions within the air ducts,’ says Bane. ‘Now the ABB drive is connected to the building automation system and varies the fan speed to maintain a constant duct pressure. It saves energy and makes the whole system more stable.’
According to Bane, the FA is still in the process of quantifying the energy savings from the drive. Any quantitative assessment is complicated by the fact that the addition of the humidification unit is also saving energy, because passing the air over the water cools it down and makes the air conditioning less reliant on electrical cooling.