Heating - Solar air heater - Residential - Glazed

Template assignment

Base Case

• Residential building with an indoor temperature of 21ºC and maximum air temperature of 50ºC
• Thermal resistance (R-value) of the walls is 4.0 m² - ºC/W
• Design airflow rate is 3,000 m³/hour
• The building ventilation system is operating 24 hours per day, 7 days per week
• Electric resistance heating with an efficiency of 100%
• Electricity rate is $0.10/kWh

Proposed case

• The base case electric heater is supplemented by a 125 m² glazed solar air collector array that preheats the ventilation air
• Gross area of each solar air collector is 2.50 m² and aperture area is 2.30 m²
• The collector has a Fr (tau alpha) coefficient of 0.60, a Fr UL coefficient of 5.80 (W/m²)/ºC and a temperature coefficient for Fr UL of 0 (W/m²)/ºC²
• The collector is mounted on a south-facing (azimuth is 0º) vertical wall (slope is 90º)
• The percentage of time that the heating ventilation system is used are as follows:

• The ventilation fan consumes an additional 3 W/m² of collector, compared to the base case
• The installed cost of the collector is around $520/m² for this installation
• Maintenance costs are the same as in the base case
• Building heat loss recaptured are considered to be nil

Solution

The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.