Modeling the effect of dual-core energy recovery ventilator unit on the energy use of houses in northern Canada

Abstract

The use of single-core energy recovery ventilator (ERV) reduces the heating energy use in northern houses, but has the disadvantage of reducing the required outdoor air supplied to the house during the defrost operation by air recirculation, which might affect the indoor air quality. A dual-core ERV also reduces the heating energy use, but in addition supplies a continuous outdoor air flow rate in compliance with standards. This paper evaluates the advantage of using the dual-core ERV in northern houses. First, this paper presents new correlation-based models of supply air temperature and humidity after the ERV unit, based on laboratory-controlled experimental data. Second, the energy use for ventilation and heating, and ventilation rates are simulated with TRNSYS program for northern houses at three arctic locations. They are compared with Montreal conditions as reference. The single-core ERV unit significantly reduces heating energy use in arctic locations by about 27%, compared with the case without heat recovery, however the outdoor airflow rate during the defrost is smaller than minimum standard requirements by about 13% in Kuujjuaq (below Arctic Circle) and 24% in Resolute (above Arctic Circle). The dual-core ERV unit removes the frost while continuously supplying the minimum required outdoor air to the indoors, however at the cost of minor increase of the heating and fan energy use compared with the single-core ERV unit.