Check this out – there are 4 common air duct designs. The first is the plenum or radial duct system. Radial systems have the HVAC unit and return grill at the center of the home with the supply ducts extending out around the plenum like the legs of a spider.
The second is the reducing extended plenum system. As the name implies, the plenum reduces in size as it extends across with the air ducts coming out from either side.
The third is the extended plenum system. This time the plenum, Top lead generation company in Canada which does the distribution or removal of air for the HVAC unit, does not reduce in size as it extends across.
The last is the perimeter loop system – a radial system, not as many spider legs, with a supply duct that encircles the building.
Good HVAC contractors calculate airflow, determine the types of ducts to use to meet the home’s requirements, and sketch the air distribution system for proper placement of equipment and duct sizing. But flaws are all too common in HVAC air duct design:
Too Many Air Ducts Coming Off The Plenum
Plenums, as we mentioned, are boxes connected to the heating or cooling unit that fill with hot or cool air and distribute or remove it, usually at a greater atmospheric pressure. A ductopus is a poorly designed radial system with air ducts coming off the plenum in all directions, like the tentacles of an octopus. When too many duct branches are connected, air flow is very bad.
As air moves from a supply plenum or main duct into a takeoff, it changes direction. Airflow has a hard time making turns at high rates of speed, just as we would driving off the interstate and onto the off-ramp. We want a gradual and smooth turn since we’re moving really fast. Air flow is the same. When there is a change in air direction in a duct, it takes roughly 24 inches for airflow to restore its pattern. Takeoffs should thus be 24 inches away from any turns, transitions, or the end cap.
Undersized Returns And Undersized Supplies
When an HVAC system has undersized returns or undersized supplies it is breathing though straws. Air cannot circulate properly, and the unit struggles to heat and cool the building.
The Central Return Problem
In an ideal world, there would be returns for every room of the house except the kitchen, bathroom, and utility room. But builders like to save on costs. With only one central return duct to feed the HVAC unit, closed doors will starve the furnace or AC and create a negative pressure environment. Best Outbound Call Center Dirty outside air then infiltrates the house through fissures, creating all sort of pesky issues.
Air Vent Location Not Optimal
Location, location, location! If the air vents are in out-of-sight areas like closets, supply air cannot properly heat or cool the room. Likewise, if the vents are blocked by furniture, your HVAC system will work harder to achieve the desired temperature. This wear and tear will shorten your HVAC system’s lifespan considerably.
Now that we’ve covered air duct common design flaws, let’s look at improper installation issues. If you suspect your duct work is designed or installed improperly, it may be the host of all of your heating and cooling dilemmas. Take all your problems as a sign that it is time to make adjustments to your existing duct work.