Tips & Secrets to Choosing
a New Heating & Cooling System

How to save thousands of dollars and tons of headaches when shopping for a new system

An Important Decision With Long Term Implications

Buying a new heating and cooling system could actually be one of the most important financial decisions your family makes this decade. What you pay to buy and install the new equipment -- which can be thousands of dollars -- may be just the tip of the iceberg.

More important, you’re giving your utility companies permission to send you a bill for using the new system each month. You’ll also have to maintain it, and pay to fix it if and when it breaks down. And over time, the combined costs of operating and maintaining a system always far exceed the initial cost of buying it.

The wrong system, improperly installed, could sentence you to over 20 years of excessive utility and repair bills. It may also not deliver the comfort you are hoping it will, and may even adversely affect your family’s health and safety.

So the first thing you need to know is: don’t rush into your decision. If you make the wrong choice, you probably won’t be able to justify tearing it out and starting again. You’ll literally have to live in your decision for as long as you own your home.

The Dirty Industry Secret About Replacement Equipment

A dirty industry secret is that while a few people who buy a new energy efficient system save a lot, most people see only some savings on their utility bills, and some people don’t save a dime. Only a small fraction of newly installed systems perform at the efficiency levels they are capable of.

There’s a lot more to efficient operation than the manufacturers’ ratings. These efficiency numbers are measured in a controlled, ideal laboratory setting. A lot can and does go wrong when a contractor takes the equipment out into the real world and installs it in your home. Most homeowners are simply not getting the efficiency they’re paying for. Don’t let it happen to you.

The Three Reasons Why Your New System May Not Work the Way It’s Supposed To

1. Make Sure Your New Equipment Is The Right Size

When it comes to air conditioning, bigger is NOT better. Many contractors will readily sell you a bigger unit than you need. It costs you more to buy, and it can cost a LOT more to operate and service.

An oversized system will come on, run for only a few minutes and then shut down, and never get up to its rated efficiency. It’s kind of like stop and go city driving. Short run cycles are less fuel efficient, don’t evenly cool or heat all the rooms in your home, and are a lot harder on the equipment.

An oversized air conditioner also won’t run long enough to pull the humidity out of the air in the summertime. There’s nothing worse than feeling cold but damp inside a home in the summer.

A good contractor will want to carefully measure and inspect your home, its insulation levels and which way the windows face. He will recommend an Infiltrometer blower door test to measure your home’s air infiltration levels and identify the major energy leaks. And once all the information is collected, he will perform a computerized heating and cooling load calculation to pick the right size equipment for your home: not too big and not too small. He’ll also guarantee that it will keep you comfortable on the hottest days or coldest nights.

However, even a perfect air conditioning unit won’t be able to keep you comfortable if there are hidden, uncorrected house insulation problems. It’s kind of like having a car with a fuel line leak: the engine may be in perfect shape, but your mileage is awful.

For example, a common comfort problem is having an upstairs that’s never the same temperature as downstairs. During his inspection process, a good contractor will uncover and identify any areas where insulation is missing or deficient. He will then recommend improvements to your home that would make it more comfortable, allowing you to buy a less expensive, smaller size heating or cooling system, that saves you money each month on your utility bills.

2. Make Sure It’s Installed Correctly

Many poorly trained or careless technicians often create problems when installing or servicing a new system. For example, the copper tubing that connects the inside and outside components of most air conditioners and heat pumps has to be the right diameter. Many new high efficiency systems need bigger copper lines. And they almost all need a new indoor evaporator coil to work properly.

The evaporator coil is a big radiator that’s hidden inside your ductwork or air handler. A negligent contractor may either not know the evaporator -- or the copper lines -- need replacing, or they may not tell you about it, thinking you won’t want to pay for it. But they're doing you no favors. You’ll end up paying for not replacing them because of higher utility and repair bills. They’re designed and rated to work together. It’s kind of like buying a new pair of gloves. You have to get a right hand and left hand glove at the same time!

A related problem is ensuring the new air conditioning or heat pump system has the proper refrigerant gas charge. Many contractors make no correction for the actual length and internal volume of the copper lines in your system. They just crack open the valves and use whatever charge came in the new unit from the factory. A recent study by a major electrical utility found that 79% of the systems had either significantly too much or too little refrigerant gas.

And finally, the poisonous exhaust gases from gas and oil furnaces and water heaters must be vented properly out of your home. An unscrupulous contractor may install a new system without making required upgrades to the chimney, literally threatening the lives of your family.

How to tell if your contractor understands these issues:

A good contractor will be able to describe step by step how his technicians will install the new unit, and then how they commission it to ensure it is operating properly. Ask to see a copy of their quality assurance process that ensures that the mechanical aspects of your new system work the way they’re supposed to. He’ll also be able to provide proof of attendance and ongoing continuing training for his technicians at industry and manufacturer trade schools.

3. Make Sure Hidden Problems In Your Home’s Existing Ductwork Are Repaired

Recent scientific research indicates that your home’s ductwork probably has a whole host of hidden problems that will affect your new system’s performance. There are four key problems that must be investigated and resolved:

1. Unlike big commercial buildings, most residential duct systems were never engineered or balanced to properly distribute the air where it’s needed in the home. This makes some rooms too hot or too cold.
2. Ductwork that passes through unconditioned spaces often doesn’t have enough insulation. The warm air gets cool, and the cool air gets warm.
3. Duct systems also often have hidden restrictions and design errors that choke the air flow through the equipment. Low airflow through the equipment wastes energy, reduces the heating or cooling you get from the unit, and can cause premature equipment failure. With furnaces, low airflow can actually create a dangerous fire hazard. A recent electric utility study found that over two thirds of residential systems had restricted airflow.
4. In many duct systems, the single biggest problem is that they leak incredible amounts of air. Nationwide, it’s been estimated that the energy wasted by duct leakage is the same as produced by 15 nuclear- or coal-fired electric power plants! A recent study by a US Department of Energy lab discovered one key reason: gray duct tape is virtually worthless for sealing ducts! What’s more, duct leaks can also bring in dirty, contaminated air from places like your attic, garage, crawlspace or basement.

Another Department of Energy study states that because of all these problems, (and here’s the quote): "Typical duct systems lose 25 to 40 percent of the energy put out by the central furnace, heat pump or air conditioner."

A top notch contractor knows that at least half the system’s performance actually depends on the ductwork. Before he gives you a price for a new system, he will check the existing static pressure in the ductwork, kind of like how a doctor measures blood pressure. He will recommend using special computerized test instruments such as an Infiltrometer blower door, smoke generators and an air flow capture hood to identify air leakage and delivery. And he’ll evaluate and recommend options such as duct renovation and maybe zoning dampers to bring your duct system up to needed performance levels.

These duct repairs are much more economical to perform when the new equipment is going in, especially the problems that are right at the equipment. And once duct repairs are performed, the contractor will perform a series of quality control tests on airflow and tightness to ensure you get what you’re paying for, and show you the results.

Most Contractors Don't Know or Don't Care

Most homeowners who buy new comfort equipment don’t get anywhere near the comfort and efficiency they could from their new system. It's almost entirely due to contractor ignorance. Homeowners rely on the contractors, but very few of them are even aware of the important new research on these factors affecting system performance.

And even more sadly, we find that most contractors simply don’t care. They just want to sell you a new metal box, slap it in, get it running, and move on. Needless to say, the most important part of your buying process is to pick the right contractor.

 
Next: 15 Questions to Ask a Heating & Cooling Contractor

© 1999 Comfort Institute Inc. Reprinted with permission.