All information below is direct from the Comfort Institute:
The US Department of Energy Says:
90% of Newly Installed Systems Have Energy-Wasting Mistakes
Some are errors by the installing contractor.
However, most of the waste comes from connecting new HIGH-efficiency equipment to the old LOW-efficient ductwork.
The old ducts are usually the weak link in the chain. The new system may be “working,” but not to its full capabilities.
Homeowners who miss out on duct upgrading often see little – or none – of the promised utility bill savings or comfort improvements.
Existing Duct Systems Are Inefficient
Today’s most stringent building codes now required sealed ducts…but 90%+ of older duct systems leak excessively. Most are also undersized which chokes & restricts the airflow.
It just makes sense to also fix the ducts to get the promised performance from a new system.A duct system upgrade is a great investment. Authorities say it is “free” as it pays for itself through lower utility bills – equal to a 10% to 33% annual return on investment, tax free. Many utilities even offer $ rebates.
Your Heating and Cooling System Is More Than Just The Equipment
Your furnace, heat pump, or air conditioner is the heart of your comfort system. The air ducts are its veins and arteries. When doing an “HVAC heart transplant” it makes sense to ensure its arteries are not “blocked or hemorrhaging.
Replacing just the HVAC equipment is often like putting a new more efficient engine into an older car with a worn transmission, bald underinflated tires, and a leak in the gas tank. It’s just a more efficient way to be inefficient.
Authorities say: slow down, look at the big picture, and have your contractor ensure your new equipment will work well with your old ducts.
Old Ducts Can Strangle New Equipment
Restricted undersized ductwork is like choked inflamed airways for an asthma sufferer.
If your old ducts are too small, the new indoor fan motor will strain to push the air, greatly increasing electrical consumption and noise.
Ask your contractor if enlarging your return air duct(s) will help your new unit breathe easier.
New Equipment Alone Will NOT Solve Hot/Cold Room Problems
Old unit didn’t keep up? Hot/cold spots? Bigger equipment will often make comfort issues worse.
The real causes of discomfort are usually a weak duct system and/or missing house insulation and air leaks. A duct upgrade restores output and gets more conditioned air to the problem areas. You will enjoy more even temperatures.
Duct sealing also improves humidity control. Your air will be less humid and sticky in summer and not so dry in winter.
Sealed Ducts = Less Duct & Healthier Air
Sealing ducts just makes sense: stop wasting money and improve comfort. But for many families, the biggest benefit has been an immediate reduction in dust on the furniture and less allergy and asthma suffering.
Even many homes with ducts “inside the house” inadvertently suck nasty insulation fibers, bugs, mold spores, pollen, rodent allergens or carbon monoxide from the attic or garage into the home – via gaps in the hollow wall and floor cavities used to carry return air.
Sealing duct leaks will also help keep your ducts and equipment from getting dirty – which reduces future repair and utility bills.
“Fumes from household and garden chemicals, insulation particles, and dust can enter your duct system, aggravating asthma and allergy problems.
Sealing ducts can help improve indoor air quality by reducing the risk of pollutants entering ducts circulating through your home.”
Sealed Ducts Help the Environment
Duct leakage wastes $25 billion each year nationwide. If every homeowner in America sealed their ducts, the US Environmental Protection Agency says the environmental and National Security benefits would be the same as:
Shutting Down 12 Nuclear Reactor
Not Burning 250,000 Railway Cars of Coal Every Year
Not Importing 48 Supertankers of Middle East Oil Every Year