Retrofitting

There are many roof penetrations in a complex building, for roof-mounted air-conditioning equipment and exhaust fans. These devices are usually installed on curbs which are sealed into the roofing material. With time the pitch hardens, […]

Cooling towers operate by evaporative cooling, lowering the temperature of water by forced evaporation. When a portion of water evaporates, it must absorb enough heat from the body of water to vaporize. This is how […]

It is not uncommon for ductwork, especially warm-air ducts, to be installed without insulation. When this duct is routed through ceiling spaces or unconditioned zones such as mechanical rooms or basements, the thermal losses can […]

Most HVAC systems cool air to a space temperature of 75°F or thereabouts, with a temperature leaving the coils of 55°F. This has been the standard for many years, though now systems are being developed […]

Many older buildings were designed with dual-duct constant-volume HVAC systems. The air handler runs at a constant speed and delivers the same volume of air to every zone at all times. The temperature of the […]