Why sojol?

Solar air heating is relatively new and solar air cooling using a solar air heater is brand new to the global market. So what are the benefits of solar air heating and cooling compared with other forms of ventilation, heating and cooling?

As power costs increase and health issues continue due to inadequate ventilation, solar air heating/cooling is likely to become a more common form of ventilation in the future. Houses are becoming better insulated which then require some form of controlled ventilation. Sojol's system is cheaper, healthier, regulates temperature and overall decreases the building’s environmental footprint. Most importantly it introduces fresh air, dehumidifies and is safe and easy to use.



1. Fresh air ventilation

Positive pressure systems in NZ often source air from the roof cavity. Heat pumps recycled stale air, and so are not ventilating appliances. Sojols solar air heater/cooler is first and foremost a fresh air ventilation tool to enhance indoor air quality while contributing significantly to heating and cooling. The specialized patented design allows for excellent large volume fresh air flow capacity to exceed NZ and Australian standard of ventilation (G4.3.1 Spaces within buildings shall have means of ventilation with outdoor air that will provide an adequate number of air changes to maintain air purity). It was noted that testing showed no significant pressure loss through the tubes at high flow rates.

Fresh air ventilation continues during non-solar periods with Sojol’s air heater.

2. Balanced pressure

Sojol’s solar air heater/cooler balances air pressure alongside trickle ventilation. In temperate climates, the solar air heater/cooler pumps fresh air into the interior for most of the year. With increasingly well-insulated houses and for it to work most effectively, stale air must be exhausted through some form of trickle ventilation. While on a very hot summer’s day, the solar air heater exhausts stale air and inhales fresh air from the cool side of the building. For hotter climates, Sojol's indirect evaporative cooler can be added to the system with the solar ventilator exhausting stale air. This stale air dries a desiccant wheel in the evaporative cooler resulting in a balanced pressure system that efficiently and cheaply provides fresh cool air to the building.

3. Renewable energy saves money

On average about a third of total power costs is for space heating. Power savings from using solar energy will pay for the cost of the solar air heater/cooler. After a few years solar energy is free.  It will protect your greatest assets, your health and your home, from future electricity price increase.

4. Lower running costs

Not only does Sojol’s solar air heater/cooler supply free solar heating and cooling, but also fan energy is boosted by natural thermal siphoning, thus further reducing power costs. This occurs naturally due to the large heat differential between temperatures inside and outside the heater.

5. Heating

Sojol offers significant supplementary heating in the colder season.  People tend to switch off when not home to save power, whereas solar energy with ventilation can be harnessed all day long leading to a healthier, warmer and drier home environment after work, thus increasing both comfort and the life of the building. The heat storage capacity extends solar air heating well into the afternoon. Sojol's air heating system can be added to the system in order to boost solar heating if required during solar hours and to provide heating during non-solar hours.

6. Cooling

For some of those long summer days a means of cooling can lead to a more enjoyable summer. In cooling mode, Sojol’s heater combines with trickle ventilation to cool fresh air as it enters the building and exhausts it via the solar air heater. Natural thermal siphoning takes care of a lot of the ventilation aided by a fan.

In summer the whole house can heat up and be unbearably hot in the late afternoon. The roof-mounted solar air heater can remove heat from the roof space as well as the house, thus rapidly cooling the building, During the evening and at night, the solar air heater automatically switches modes to introduce cool fresh air from outside to further speed up temperature reduction.

In more extreme hot climates, an indirect evaporative cooler can be combined with a solar ventilator to supply cooler air significantly reducing cooling costs.

7. Humidity Control

Sojols solar air heater dries the air during solar hours. A snap shot was taken in winter (19th Aug 2016 at 11.55) with a flow rate of 660m3/hr. (Electronics, fans and ducting installed by SIMX). Moisture levels entering the solar air heater was 66% whereas it had dropped to a mere 16% after it had gone through the tubes of the solar air heater. At no stage during testing did the solar air heater itself show any sign of condensation due excellent insulation and to constant appropriate ventilation.


8 & 9. Convenient, quiet and discreet

When connected to an intelligent system controlled by thermostats, solar air heating/cooling and heat exchange automatically adjusts to heating/ cooling requirements. Being very quiet and discreet when blended into the interior décor, it’s barely noticeable.

Sojols solar air heater is low maintenance.

  • Wall-integrated heaters/coolers require a periodic filter clean by the homeowner, and a service every 4 to 5 years. They are easily accessible from inside the building and come with the option of increased filtration efficiency at the outlet for polluted environments.

  • Roof-mounted solar air heaters are also easily accessible for long term maintenance. Its lid hinges on the lower side allowing easy access to clean and service the tubes every 4 to 5 years. Ducting from the roof-mounted heater/cooler connects to standard HVAC filtration, ducting, fans in the roof space.

  • Filtration for the air heating unit is also easily accessible for cleaning and maintenance.

All designs are available as 3D models and demonstrate the ease of long-term servicing.