Are you looking to reduce your building’s energy costs? According to the U.S. Department of Energy, leaky ductwork is one of the biggest contributors to energy waste in U.S. buildings today and the D.O.E. now ranks duct sealing as one of the most effective things you can do to reduce your overall energy costs.
There is a simple solution to this costly problem. You can reduce your energy consumption by sealing your building’s ductwork with Aeroseal. It simply works better than trying to plug leaks manually with tape or mastic. The Aeroseal sealant can “find” leaks that you might miss on a visual inspection, and since it is applied through the air inside the ducts, access is not a problem. And the Aeroseal sealant is more durable than tape or mastic. This means that with Aeroseal, you can reduce more leakage and keep it reduced.
Leaky ducts force your fans to work harder and your system to heat or chill more air. This wastes energy and therefore money in several ways:
- Fan horsepower.
When supply ducts are leaking, the fan has to send out more conditioned air to get the occupied spaces in the building to the right temperature. This means that the fan is using more horsepower. The fan affinity laws say that the increased horsepower varies with the cube of the ratio of the actual to design CFM, or HPactual = HPdesign X (CFMactual/CFMdesign)3. Simulations have suggested that due to obstructions like reheat coils in supply shafts, the real-life impact is that horsepower really varies at something like the 2.4 power, so, for example, field testing has shown that a 15% increase in duct leakage led to an increase of supply fan power of 37%. For exhaust systems, with generally fewer obstructions, the relationship tends to hold closer to the theoretical varying with the cube, so a system that leaks 20% may use 95% excess fan power.
- Heating and cooling load.
All of that extra air has to be heated or cooled. And if your system is out of balance, your building could be drawing in un-conditioned air through cracks around doors, windows, or other openings in the building’s shell.
- Fan Motor Heat.
A harder working fan generates more heat. If that fan is in the conditioned air stream, then during the cooling season this means extra cooling load on the system.
- Maintenance and repair.
Systems that are working longer and/or harder are at risk of wearing out their components and needing repair at a faster rate than systems that don’t have to work so hard.
It is important to note that in order to capture these savings, it is likely to be necessary to adjust fan speeds and test and balance HVAC systems after sealing the ducts.
Read some interesting case studies on saving money below.