Strategic lab AHU zoning can reduce energy costs
By Brandon Fortier
In the science and technology market, one often-overlooked energy-saving strategy involves zoning laboratory support spaces onto the same air handling unit as the laboratories they support.
Consider that most laboratories are driven by minimum exhaust air rates requiring an equivalent amount of makeup air that needs to be conditioned (i.e., heated, cooled, dehumidified, or humidified depending on ambient conditions). On the other hand, many support spaces (e.g., conference rooms, offices, etc.) are driven by ventilation codes for human comfort but do not need to be exhausted. When these spaces are served from the same AHU the return air from support spaces can be used as makeup air for the laboratories at a fraction of the energy required for using ventilation air as makeup air.
The location of support spaces in relation to laboratories and pressurization requirements can make this strategy difficult to implement. Therefore, the design team should review with the owner early in design which support spaces and laboratories are co-located and explain how increased ventilation loads impact construction costs (due to increased equipment size) and long-term energy costs due to increased heating and cooling system operation. If possible, early energy modeling should be implemented to evaluate the long-term energy implications.
Where permissible by codes and standards, zoning laboratories and support spaces on the same AHU can provide significant benefit to laboratory owners, substantially reducing energy consumption and expenditures for the life of their building.