Rethinking Occupancy - Based Ventilation Controls

Conference · Mon Jan 01 04:00:00 EST 2018

OSTI ID:1602818

Walker, Iain ^[1]; Less, Brennan ^[1]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area

Traditionally, occupancy-based ventilation controls have only ventilated when occupants are present – usually based on measurements of CO2 and/or humidity. These indictors may be fine for pollutants released directly by occupants, such as bioeffluents, or by their activities, such as cooking and cleaning. However, they do not account for pollutants not associated with occupancy, such as formaldehyde from building materials and furnishings. In this study we examined how occupancy-based ventilation controls could account for these other pollutants using the relative exposure approach for variable ventilation. A real-time control was used for exhaust and balanced fans, three occupancy schedules and two different pollutant emission assumptions using the REGCAP ventilation and residential energy simulation program. The simulations were performed for a prototype high performance home compliant with U.S. Department of Energy Building America Zero Energy Ready program requirements in the 15 climate zones defined by the U.S. DOE. Median ventilation energy savings were between zero and 26% of ventilation-related energy use depending on the occupancy schedule, climate, fan type and emission assumptions. Occupancy-based control savings increased for balanced ventilation fans, reduced emissions during unoccupied periods, and longer unoccupied times. Accounting for pollutant emissions during unoccupied times significantly reduces the energy savings for occupancy-based controls.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Building Technologies Office (EE-5B)
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1602818
• Country of Publication: United States
• Language: English