Economizers and Free Cooling

An economizer is a part of a building’s cooling system that uses cool outdoor air to cool the building instead of operating the air conditioning compressor.   An economizer is an optional feature to an HVAC air handler that draws in outdoor air and mixes it with...

Homes Need Ventilation

Most modern homes need mechanical ventilation systems to provide satisfactory indoor air quality. Many poorly ventilated homes have mold and mildew growing in wall cavities, high levels of airborne chemicals, combustion byproducts, or high utility bills. It’s...

What is Draft

What is draft? Draft is important to combustion efficiency and safe combustion. If draft isn’t adequate, chimneys can backdraft or spill.  We measure draft between between two places in a combustion heating system. For example, we measure draft between the a...

LBNL “Smart Ventilation” Research

Lawrence Berkeley National Lab (LBNL) scientists, led by Max Sherman and Iain Walker, are investigating whole-house ventilation options to support California’s Zero Net Energy Homes initiative. This research project is called Smart Ventilation for Advanced...

Sliding Glass Doors: Comfort and Energy

Sliding glass door heat flow A sliding glass door’s large expanse of glass transmits a lot heat out of the home in the winter and into the home in summer. This heat flow takes three forms: heat conducts directly through the glass in winter, solar heat transmits...