Advanced Residential Load Reduction Pilot Project – A field trial of centrally zoned forced air systems

Publication date: March, 2011

The ZoneComfort® (ZC) technology enables occupants of suitably equipped forced-air conditioned homes to direct and schedule the delivery of heating and cooling to multiple zones in the home. By way of a field study conducted across Ontario from 2008 to 2010, this project monitored approximately twenty occupied homes equipped with the forced air ZC system. Site and equipment specific electricity was collected for these sites along with electricity and natural gas billing data. In addition, the project followed control homes similar in structure to the ZC homes over the same time period. As well, questionnaires were administered to the homes for the purpose of gathering information on dwelling characteristics, demographics and lifestyle and attitudes regarding the ZC system. With this detailed data we are able to develop empirical models to measure the incremental conservation contribution of the ZC system, while controlling for weather, dwelling characteristics and demographics.

Based on this report’s analysis of the field data, there are a number of conclusions.

On average, after controlling for demographics, dwelling characteristics and weather, a ZC system annually saves approximately 7% in natural gas, 36% in electricity used by the air conditioning condenser and 7% in electricity used by the air handler and associated controls. The savings vary according to ZC configuration. With respect to natural gas conservation, largest savings are associated with the boiler and storage system; and for electricity used by the air conditioning condenser, air handler and associated controls, the largest savings occurs with the ZC power vented water heater.

A comparison was made with non ZC houses of average indoor “comfort conditions” during the peak cooling periods. The indoor conditions of the sites generally fell within the preferred ASHARE comfort zone. On peak demand days the ZC system was able to produce superior indoor comfort conditions on the top floor of the house during the critical overnight period.

90% of field participants felt the ZC system increased comfort with respect to temperature and 70% of the participants felt the ZC system both reduced energy consumption and increased their comfort with respect to humidity.

With respect to GHG savings, the study showed a reduction of 323 kg of CO2 per year per household.

For access to the full publication, please contact the CanmetENERGY-Ottawa Business Office.