Improved insulation regulations for Canadian houses have made mandatory the use of forced air ventilation systems to maintain indoor air quality. Long term ventilation may nevertheless create uncomfortable indoor air conditions and increase the energy bill when in winter, outside air introduced in the house is cold and dry and in the summer, when it is warm and humid.
The use of a passive heat and humidity exchanger, or enthalpy exchanger, makes it possible to alleviate these problems by a better control of the humidity and temperature levels of the air introduced in the house. The systems are driven by only the temperature and humidity level difference between the fresh airflow entering the house and the exhausted contaminated airflow. Active (gas regenerated) desiccant cooling systems are often used for these passive recovery applications but they are generally costly and overdimensioned.
A new passive and low cost enthalpy exchanger has been developed specifically for these applications and tested successfully. The product is based on the development of a new desiccant material and a new process for direct fabrication into an enthalpy wheel. This enthalpy exchanger presents the same performance as commercially available units, with interesting properties such as frost resistance, an important feature in cold climates.
The paper presents the characteristics of this novel product including its predicted and measured efficiencies.