Active chilled beams are specifically designed to deliver chilled air into an environment in order to achieve comfortable working and living conditions. They are terminal units for heating, ventilation and air conditioning (HVAC) systems and require a simple low velocity primary air supply and chilled water connection.
ETL compliant heating/cooling controls can be used for both hydronic and electric heating systems as well as chilled water systems. Systems are controlled by a temperature sensor and predefined temperature set-points. Further refinement to the controls can be given by activity and occupancy sensing or schedules. Wet heating systems controls also incorporate frost protection, temporary override options, and “self adaptive weather compensation”. Other features of ETL compliant products include optimum start. This activates the heating circuit at an early enough time in the morning to ensure that the zone air temperature reaches the desired set-point by the beginning of occupancy and not several hours earlier.
Close control air conditioning equipment is designed to control the temperature in rooms and enclosures containing heat-generating equipment, or processes with high sensible heat loads. It also offers the option to control relative humidity.
An evaporative air cooler is a device that cools air through the evaporation of water. They are available with a wide variety of efficiencies. The ETL aims to encourage the purchase of direct evaporative air coolers and higher efficiency indirect evaporative air coolers. Evaporative cooling is used for commercial and industrial cooling as an alternative to refrigeration based cooling and is increasingly popular in data centres. Substantial energy savings are achieved because there is less power requirement involved in evaporative cooling systems compared to refrigeration-based ones. This form of cooling offers other advantages over traditional air conditioning thanks to the fact it doesn’t rely on any harsh chemical coolants, needs no heat rejection duct, consumes relatively little power, operates more quietly, and does not lead to the dry, refrigerated air often associated with air conditioning. However it does consume a continued source of water to operate.