LBNL report: “Houses are Dumb Without Smart Ventilation”
Lawrence Berkeley National Labs declares that most homes are stupid!
Lawrence Berkeley National Laboratory has continually been at the forefront of technology development, from advanced weaponry to advanced appliances. In 2014, Walker, Sherman and Less wrote this report describing the features of a smart ventilator and how a smart ventilator can improve IAQ (indoor air quality) while simultaneously reducing a home’s energy usage. The basic idea discussed by the authors is simple: ventilate when needed or when outdoor conditions require minimal ventilation energy, and avoid ventilating when not needed.
The authors compare their “theoretical” smart ventilator to a “dumb” base case consisting of a constant flow, energy recovery ventilator. Results from a field experiment with smart controls compared favorably to the research team’s computer model predictions that demonstrated enhanced indoor air quality coupled with significant energy savings in comparison to the dumb case. Because smart controls increase ventilation when indoor pollutant levels are above desired conditions, and minimize ventilation when they are not, significant energy savings occur. In harsh winter climates with increased wind and elevated indoor-outdoor temperature differences that elevate infiltration, the authors describe how a smart ventilator automatically reduces ventilation resulting in energy reductions during the most severe weather conditions without sacrificing air quality. Their computer simulation for a smart controller predicted a 40% energy reduction coupled with 15% reduction in occupant exposure to indoor pollutants relative to the dumb, constant flow ventilator. LBNL’s field data demonstrated 55% energy savings coupled with a 20% reduction of occupant pollutant exposure.
Overall, the authors list the following desirable features for a smart ventilator:
1) “understand and calculate indoor air quality”
2) “operate in real time”
3) “be capable of sensing relevant control factors”
4) “be able to change ventilation rates or schedules in response to inputs”
5) in addition, a smart should be able to leverage any of the following inputs: Outdoor air quality; Outdoor thermal conditions; Utility rates; Occupancy; Exogenous Ventilation (eg, kitchen, bathroom ventilation); Key contaminants; Infiltration
Coincidentally, Build Equinox’s CERV, the first smart ventilator in the market, received UL approval and entered the market in 2013 with all of the features described by the authors and more (CERV-ICE cloud connection with “over-the-air-upgrading”, Geo-Boost hybrid geothermal/air source operation, automatic kitchen/bath venting airflow enhancement, control of central and distributed HVAC systems, hybrid (heat pump) water heater and hybrid (heat pump) clothes dryer air distribution, and more to come).