Whenever possible, Joshua Hoffman of Hoffman HVAC prefers custom craftsmanship over prefabricated materials. “Prefabricated fittings that you find at supply houses are just that,” he says. “They work and are good quality, but they have never seen the job, nor do they know the static pressure of the existing duct system.” 

For a newly constructed home in Swartz Creek, Michigan, Hoffman fabricated a 24 gauge plenum and 26 gauge fittings to pair with a Carrier Infinity System.

“When dealing with high static pressure in AOR (add-on replacement), it is critical to do everything you can to improve it,” explains Hoffman, who has been in the HVAC industry for seven years. “This is where we have standards. Every job will get a new plenum and return drop built for improved airflow. Our goal at completion is always hitting 0.5” external static or better.”

Installation took five days from start to finish — three days for ductwork fabrication, a day for equipment and another for commissioning. Hoffman uses Wrightsoft HVAC software for load calculations and duct design. For fittings, a tape measure and a note pad.

“I usually can go into an AOR job, take a few measurements and be able to make all the ductwork for the job beforehand,” he says. “This helps a great deal during the heat of the summer or the bitter cold of the winter here in Michigan.”

This story originally appeared in the September 2019 issue of SNIPS magazine.