The improvement to the system in the Soho Square building was spurred by the need to include humidification in the building 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 making everyone feel more comfortable.
Energy savings from the drive have not yet been quantified. Any assessment is complicated by the fact that the humidification unit also saves energy because of its cooling effect on air, making the air conditioning less reliant on electrical cooling.
The air in the building is filtered, and the pressure drop across the filters changes as they accumulate dust. The AHU previously supplied air as if it were working against the maximum back pressure from the filters.
David Bane says, ‘ We used loads more energy and we’d also find unstable pressure conditions within the air ducts. 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.’
