ABOUT
A NVAC greenhouse is an open roof design improved by coupling natural ventilation with an unconventional misting system. The misting system located in the rafters of the greenhouse sprays a mist of water into the rising warm air. The newly cooled air flows down onto an added inside roof and collapses into the lower space of the greenhouse. The added roof is installed so as to guide the cooled air and keep the fine water droplets from falling directly onto the plants. This effect cools the air and enhances air movement in the greenhouse without using fans.
With an increase in relative humidity within optimal limits, air cooling of up to 5ºC and increased airflow in the order of 1 m/s is possible in the tropics, all the while preventing water droplets from reaching the plants.
View in the rafters of the NVAC greenhouse located in Barbados. Black nylon misting line tubing with stainless steel nozzles seen in (A) and NVAC roof seen in (B).
Prototyping began in 2012 at at the Macdonald campus of McGill University located in Ste-Anne-de-Bellevue, QC. Testing was done during the warmest days of the summer months, when daytime temperatures exceeded 30C. When the misting system is operational, a significant temperature decrease and added air movement is noticed in the NVAC greenhouse. Unlike other evaporative cooling methods, this system does not require use of active ventilation.
A research NVAC greenhouse was built in 2016 at the Bellairs Research Institute of McGill University, in Holetown Barbados. This greenhouse is currently the site of research on tropical region protected agriculture.
A commercial NVAC greenhouse was built in 2014 in St-James Parish, Barbados. Development continued until July 2016. Cooling and air movement occur as a result of the NVAC design, increasing the capabilities of a traditional natural ventilation greenhouse.
A research NVAC greenhouse was built in 2016 at the Bellairs Research Institute of McGill University, in Holetown Barbados. This greenhouse is currently the site of research on tropical region protected agriculture.
A commercial NVAC greenhouse was built in 2014 in St-James Parish, Barbados. Development continued until July 2016. Cooling and air movement occur as a result of the NVAC design, increasing the capabilities of a traditional natural ventilation greenhouse.
Copyright © 2013 - 2018 Lucas McCartney