Manual D Ductsize (MDD) is a fast and simple program designed for sizing and analyzing HVAC duct systems based on the Air Conditioning Contractors of America’s (ACCA’s) Manual D procedures. It ...

This is the first in a series of articles intended to provide a working knowledge of residential heating-cooling duct systems; an understanding of the major issues concerning efficiency, comfort, ...

ALLENTOWN, PA - January 12, 2026 - PRESSADVANTAGE - PJ MAC HVAC Air Duct Cleaning announced the launch of a new ...

Household air pollution killed 3.2 million people in 2020, according to the latest data from the World Health Organization (WHO). Considering that the average American spends approximately 90% of ...

Compare plans tailored to your home & budget. If your home has mold or vermin or the ducts are particularly clogged with dust, then cleaning them may be a good idea to freshen up your home’s air.