Retrofitting

Direct-expansion (DDX) air-conditioning or heat-pump systems have an outside condensing unit with finned coils. Air is drawn past these coil banks to extract heat from the refrigerant flowing inside the coiled loops of tubing. The […]

A standard protocol applies to furnaces, makeup-air heaters, and unit heaters: 1. Keep all heat-exchange surfaces clean. Heavy fouling may indicate improper air-to-fuel ratio, which should, in any event, be checked and adjusted on a […]

Time clocks are a simple and inexpensive way to reduce space-conditioning costs. The equipment can be turned off at the close of business every day so that cleaning crews or late-working tenants don’t keep the […]

Large air handlers are usually located in their own mechanical rooms and are easily accessible for maintenance. The engineering staff should be vigilant for air leaks at flex connections, filter sections, and duct joints. It’s […]

The variable air volume (VAV) system provides a variable quantity of air to a zone, in response to a signal from the thermostat. At any given moment, the ft3 per minute of air delivered by […]