Andrea Eng, M.Eng. 2016
Supervisor: Bo Li, M.A.Sc., P.Eng, BESA™, CEM®
Houses are built more airtight these days. The lack of airflow through cracks in homes with no mechanical ventilation systems no longer provide adequate air exchange in a home for a healthy living environment as it did in the past.
The goal of this study was to investigate the energy performance of a balanced ventilation system compared with a Heat Recovery Ventilator (HRV) ventilation system in a heating only system with electrical baseboards and a fully air conditions system with an air-to-air heat pump system in three different cities (Vancouver, Edmonton, and Ottawa) in Canada.
There will be twelve models simulated. In each of the three cities, an electric baseboard and a heat pump system will be modeled with either a balanced ventilation system or an HRV ventilation system.
A 3D model of a typical one bedroom apartment was built using Trnsys3d plugin in Google Sketchup. The 3D model was imported into TRNSYS where the mechanical systems were modeled and the energy consumption was simulated.
TRNSYS was used in this study, and the results show that an HVAC system implementing HRV does not always consume less energy when comparing with a balanced ventilation system. Installing an HRV consumes more cooling energy annually because the system does not take advantage of free cooling. The HRV does reduce the overall heating energy but uses more fan energy when compared to the supply and exhaust fans in the balanced ventilation system.
The overall energy savings when implementing a HRV with an electric baseboard system was 215 kWh, 747 kWh, and 759 kWh in Vancouver, Edmonton and Ottawa. The overall energy savings when implementing an HRV with an air-to-air heat pump systems was -647 kWh, 1272 kWh, and 1225 kWh in Vancouver, Edmonton and Ottawa. More overall energy was consumed when an HRV was installed with an air-to-air heat pump system in Vancouver.
In conclusion, the climate, fan choice (exhaust, supply and HRV), type of air conditioning system play an important role on the amount of energy savings achieved by the mechanical system.