In March, you will hear a featured video regarding static pressure and why VICCARONE HVAC chases the lowest number. Well, let's dive a bit more into details on what static pressure is and what it can or cannot do to the effectiveness of the residential HVAC systems—using numbers lower than .5 w.c. Our goal is across the total system, and we consistently achieve it in the designs. We can design and test the system with proper load calculations and exceptionally well-installed duct systems.
Static pressure is the resistance to airflow in ductwork. Air does flow more accessible in a radius, curved or triangular fitting over a right-angled or square fabricated box. To improve it, our fab shop uses inside /outside radius designs in all fabricated fittings we produce. We want the air to flow to its supply endpoint with the least restrictive path. Depending on your equipment, we want the equipment to function, rated 92% or 96% or 98% efficiency.
We want the running "motor loads" to be as low as possible when calling for run time. We want solid run times once equipment kicks on to satisfy heat or cooling based on equipment sizing. The primary energy surge is at the start-up time, and once running, it's very efficient. We don't want the equipment to short cycle based on oversized equipment and satisfy the thermostat way too quickly. That's putting undue burden and fatigue on the heat exchanger metal (heat up/ cool down/ heat up/ cool down).
Gino Viccarone has often said, "I would associate static pressure to how blood pressure works for the body." High blood pressure has many negatives, including tasking the heart to work harder, especially during exercise. Think of this in heating/cooling systems. Without restrictions in the return ductwork and across the media filter system, you can allow the supply air as it flows across the furnace and coil and, more importantly, the equipment to run at peak performance as it should be designed and sized to do so.
The static pressure national average is .82 w.c. That would equate to a blood pressure of 130/200 which one knows is not good. The difficulty with static pressure is that even a CLEAN media filter tends to restrict flow across the filter media in an area of (.15-.25 w.c.) depending on the filter. Hence, designs need to be good to achieve the numbers we achieve in total.
External static pressure allows fan speeds to run lower (more efficiently), and it also equates to minimal duct leakage. IF you are reading this article, you might have our system installed in your home.
Look at the designed fittings installed above your furnace running into your horizontal rectangular duct.
Look and always keep up on filter maintenance.
Look at the duct sealer (polymer coating) painted on your metal from seam to seam.
Look at tape joints. Look at metals bends and hemmed metal and see the precise and tight fit without gaps anywhere.
Listen for the ease of the blower motor running as the system kicks onto heating or cooling.
Feel for air leaks around the furnace, duct, pipe runs, and connections. If you feel anything, it's best to use a little silicone to mend it or duct tape to seal it off from a leak.
In new construction, trades often hit a heat run or something by accident and fracture or break a small crack in the sealer we use. Even though those small openings are inside the home's envelope, it's still good to seal them if you can.
Note: If you see a tech drilling into your furnace and ductwork, don't panic. This is normal and is needed to perform this test. After the tech is done, he will insert plastic plugs to seal the holes. If you find these holes in your system, it was likely tested.
Lastly, at Viccarone HVAC, we train installers and service techs on static pressure and airflow dynamics that make the entire system run in balance and to the most effective as possible.
Please browse our website or contact us today for more details! Viccarone Heating and Air Conditioning is here to help!