Australia: Toyesi introduces PCVER system

When growing in Australia, both heating and cooling is critical due the seasonal changes and often big differences between day and nighttime temperatures. Often, the use of heaters, chillers and ventilation is a continuous battle and wasted heat energy is typically just ejected straight out into the environment and lost, just to be replaced again later with a new source of heat. That's why Toyesi created the PCVER system.

The Toyesi heat pump PCVER System draws the heated moisture laden air from the enclosure, then using heat exchangers the captured heat energy is passed into a water circulating system to a holding tank. This water can be reused in other functions as explained later.

As the PCVER system draws and vents air from the enclosure and into exhaust ventilation system it causes a negative field in the greenhouse. This causes a natural passive ventilation into the enclosure. (Reversing the natural heat energy escaping up and out) through existing greenhouse vents. This air is often cooler and helps with air circulation.

However, a greenhouse room thermostat can be used in conjunction with zone dampers to either dump the air into the environment (waste air) or to recirculate the cooled air back into the greenhouse. This actively vented air is dissipated at the far end of the greenhouse and helps to create a cool air flow and circulation circuit results.

Passive dehumidification
Humidity capacity of air is directly governed by its temperature and its ability to absorb moisture. Therefore, the cooler air produced from the system will naturally be lower in humidity levels. The heat exchangers by-product is often copious quantities of condensate water, (physical removal of moisture from the air) further lowering the humidity levels within the greenhouse space. Some installations will provide reusable clean condensate water.

Reusing the Captured Energy
As described above you can see how the system will significantly reduce humidity and also help maintain a greenhouse enclosure temperature and airflow during the day. However, at night the system is reversed.

The holding tank during the day will continue to heat up to around 40oC or a preset temperature. At night this water is passed through the heat pump across a secondary heat exchanger and now it will heat the air that is vented from the enclosure to be then distributed through the exhaust venting system back into the greenhouse.

This system then is using the captured energy from the daytime heat (that is normally lost) to keep the space warm at night. If the heat produced is not at quite adequate levels additional heater units can be used but at a significantly reduced running cost.

For more information:
Toyesi
Mark Whorlow
mark.whorlow@toyesi.com.au
www.toyesi.com.au