Sundware Solar Air models are used ideally to heat indoor spaces in long winter seasons. Sundware Solar air offgrid, so it is totally energy free, it depends on Sun to convert sun radiation into heating the circulated air. its quite popular in North America where the heating seasons extend for more than 7 months per year.
As per statistics, number of the sunny days in heating seasons can be around 30%- 35% of the winter season, usually these days are extremely cold in most of canada and northern part of the states, this allows the solar collectors to work at its maximum efficiency.
Due to the fact that the Sun angle is much smaller in winter compared to summer time (altitude angle), the ideal position of the solar air collectors is to be vertically facing the south to absorb much sun radiation during the whole day.
The methodology of operation is through circulation the cold air into solar collector and returning it into the room on higher temperature. The main two factors in any solar air are;
1- The amount of air circulated (flow rate in CFM) which depends on the fan flow rate from one side.
2- The differential temperature (DT in C or F ) .
There is restrictions/ limitations on the temperature of the hot air which is pushed to the space, it should be taken into considerion during the design of the system, on the other hand,the fan must be selected properly to have enough pressure to overcome the pressure drop generated inside the collector!
One of the common mistakes in the solar industry is installing small fans. these fans usually are not sufficient to circulate air/ cannot generate enough flow, in this case, the inlet air temperature will be so high but almost static ( no flow) and will not be sufficient to heat the space.
Two sensors in addition to the thermostat usually control the method of operation by giving a command to the internal fan, which is in its turn, circulates the air once needed. The cold air is discharged from lowest level in the room through one of the diffusers, and then it push back the hot air to the room through the other diffuser. Selecting the proper size of solar air collectors can guarantee the maximum performance of the system and the ideal time to heat the required space.