The Jardiland Garden Centre at Montauban, near Bordeaux, is typical of large glazed retail buildings which experience uncomfortable conditions for customers when ambient temperatures rise. These conditions can be partially controlled by the use of roof vents which, using natural convection currents allow the hot air to exhaust at a high level and be replaced by cooler air from below. However, when external conditions rise above 25C, this technology becomes insufficient and conditions become uncomfortable.
Jardiland, France’s largest chain of garden centres, were seeking a cooling solution for their buildings where it is not appropriate to use refrigeration based air conditioning.
Down discharge, roof mounted, EcoCoolers were fitted to the double skin metal roof sections. Vertical, insulated ducts take the cool air to eight-way plenum chambers mounted 4m above the floor. When cooling is required the high level vents are opened fully and the EcoCoolers positively pressurise the building with cool air. The combination of positive pressure andvnatural convection forces the hot air upwards and out through the vents.
This system provides a comfortable environment for customers and protects the plants with lower temperatures and improved humidification. The coolers are controlled in two groups from a single control panel. Coolers can be run in ‘Manual’ or ‘Automatic’ mode.
- In ‘Manual’ mode there are five fan speeds and the option of running in ‘Vent’ or ‘Cool’ mode.
- In ‘Vent’ mode the EcoCooler is purely a ventilation fan.
- In ‘Cool’ mode the water circulation is enabled and the air is evaporatively cooled.
- In ‘Automatic, mode the control system links the vents, the cooler fan speed and cooling mode. As the temperature in the building rises the vents open first, followed by the EcoCooler starting in low speed, vent mode.
Finally, cool mode is initiated and the fan speed automatically rises to meet the thermostat set point. As the external temperature then falls at the end of the day this process is reversed leaving the EcoCooler off and the vents closed.