Checklist

We have rated area heating and air-conditioning services on our Ratings Tables. At the time of our last full, published article, 56 of the 221 companies were rated “superior” for “overall performance” by 90 percent or more of their surveyed customers. But 29 scored much lower, receiving such favorable ratings from only 60 percent or fewer of their surveyed customers. 

We also found big price differences. For example, to install a humidifier, prices quoted by the companies listed on our Ratings Tables ranged from $408 to $1,225. To replace the blower motor and capacitor for a gas furnace, prices ranged from $252 to $1,001. Although most consumers, surprisingly, don’t bother to get competitive bids even for costly jobs, obtaining multiple bids will save homeowners hundreds, or even thousands, of dollars. 

If you need new equipment, get several companies to prepare written proposals. Carefully compare their proposed designs because the quality of the design might affect how quickly and uniformly your house is heated or cooled, how much energy it consumes, how much noise it makes, what drafts it produces, the amount of space the system occupies, maintenance, and other important aspects of performance. 

For installation contracts, ask for performance guarantees that promise how warm the equipment will keep your house—or, for air-conditioning equipment, how cool—and how uniform the temperature within the house will be when outside temperatures reach a specified level. Also, make sure your contract clearly states the company’s responsibilities on such matters as providing an electrical supply and hooking up your equipment to the electrical panel; providing drainage for condensate; enclosing ductwork and painting and patching holes; and other matters. 

Heating and air-conditioning services are likely to push for annual professional maintenance visits, and many will offer a maintenance contract. It is not clear that such frequent professional service is needed as long as you are diligent about the most important maintenance task: replacing air filters whenever they get dirty. The case for frequent professional maintenance is strongest if your system is old and used heavily and there’s a lot of dust and pollen in the area, it frequently breaks down, or you have a large house where the energy savings from frequent maintenance would defray the cost of the contract. Before entering a maintenance contract, get price quotes from several companies and determine exactly what each contract covers. For basic maintenance—not including the cost of parts or of labor for necessary repairs—we found prices ranging from less than $100 to more than $300 per year. 

If you are considering buying new equipment, be skeptical about claims of cost savings from more energy-efficient equipment. There may be substantial savings—and there are compelling public-interest reasons to install efficient equipment—but some companies exaggerate the size of the savings in order to sell new, or more expensive, equipment. Get several companies to make proposals, ask for documentation of how much the new equipment will cut your energy bills, and ask questions. This article lists software that will let you make your own comparisons and offers examples of the effects of energy savings for different options. For many area homes, the best option may include/be a heat pump. 

Where to Turn for Advice and Good Work 

Our Ratings Tables reports ratings on area heating and air-conditioning services. The ratings on companies’ service quality come from our surveys of area consumers (primarily CHECKBOOK and Consumer Reports subscribers). We asked survey recipients to rate companies they had used “inferior,” “adequate,” or “superior” for several questions: “doing work properly on the first try,” “starting and completing work promptly,” “advice on service options and costs,” and “overall performance.” Our Ratings Tables report the percent of surveyed customers who rated each company “superior” (as opposed to “inferior” or “adequate”) on each question. The table also reports the percent of each company’s surveyed customers who rated it “adequate” or “superior” (as opposed to “inferior”) for “overall performance.” (Click here for more information on our customer survey and other data.) 

Many Washington area heating and air-conditioning services consistently provide high-quality work: 56 of the 221 companies that were evaluated in our last full, published article were rated “superior” for “overall performance” by 90 percent or more of the customers who rated them. But our Ratings Tables also reveal that some heating and air-conditioning customers get burned by shoddy service: 29 companies received “superior” ratings from only 60 percent or fewer. 

In addition to ratings from customers, for firms that were evaluated in our last full, published article, our Ratings Tables show counts of complaints we gathered from the Better Business Bureau (BBB) for a recent three-year period, the number of complaints on file with local government consumer protection offices for a recent two-year period, and complaint rates relative to the volume of work companies do. For more information on reported complaint counts and rates, click here. 

If You Need Repairs… 

If you need repairs, our ratings on our Ratings Tables will help you find a good company to perform them. 

Call one or more companies rated highly for service quality and describe the symptoms—what the system is doing and not doing. Companies may tell you over the phone what’s likely to be wrong and quote a price to fix it. If so, try to get price quotes from several companies. 

If your system just doesn’t work and you can’t determine why, arrange for a service call; you probably won’t get a price quote before you pay a company to visit your home. Your best bet is to select a company with relatively high service-quality ratings on our Ratings Tables, a relatively low price index score, and a relatively low minimum charge for service visits. 

For firms that were evaluated in our last full, published article, the price index scores on our Ratings Tables show how each company’s prices compare to other companies for four jobs priced by CHECKBOOK mystery shoppers. Table 1 shows low, average, and high prices quoted for each job, and the differences are dramatic: To install a humidifier, quotes range from $408 to $1,225, and to replace the blower motor and capacitor for a gas furnace, quotes range from $252 to $1,001. The price index scores, reported on our Ratings Tables, range from $56 to $191, which means some companies charge more than twice as much as their nearby competitors for the same work. 

Table 1—Low, Average, and High Prices Quoted by Companies for Illustrative Jobs

Since you probably won’t get price quotes over the phone, shopping for price will be difficult. What you can do is have one company visit your home, diagnose the problem, and prepare a written estimate detailing the work that needs to be done. Then, assuming the diagnosis is correct, you can call other companies and ask what they would charge for the work. 

However, other companies may be reluctant to quote prices based on another company’s diagnosis. Also, if you use a different company you’ll have to pay the first one’s minimum service call charge, which they might apply to the repair bill if they do the repair. In addition, getting other quotes will be less convenient than having the repairperson already in your home proceed with the work. 

If the repair estimate is no more than a few hundred dollars, most homeowners decide to have the company immediately go ahead with it. If that company has a low price index score, the price is likely to at least be reasonable. 

If the estimate is more than $500 or so, consider getting additional quotes. We found, for example, that for one repair job with an average price of about $800, getting three quotes would cost, on average, about $200 less than going with the first quote. Depending on which company provides the first price, subsequent quotes might save nothing (if the first quote is very low) or several hundred dollars (if the first quote is relatively high). You won’t know whether the first quote is low or high unless you get additional quotes. 

If the company that visits your home to make a diagnosis has a relatively high minimum service call charge, and will apply that charge to the price of the repair, then you probably won’t save much by going with another company. Give yourself maximum flexibility by choosing a company with a relatively low minimum charge for the initial service call. Our Ratings Tables show some companies have minimum charges of less than $70, while others have minimums of $140 or more. 

Other tips for getting good repairs at a reasonable cost: 

• When you call, describe symptoms in as much detail as possible. 
• Ask the company to explain how it calculates service charges. 
• Have the company provide a written description of needed work and total price to do it before it begins work. 
• Ask to see replaced parts. 
• Be present, but not in the way, as work proceeds. 
• Get a detailed invoice, including: 
• Description of the symptoms that precipitated repair call. 
• List of all parts replaced. 
• List of all labor charges and description of labor required. 
• Temperature at plenum of air-handling equipment and return vent before and after the repair. 
• With repairs to air conditioner or heat pump, pressure of refrigerant in air-conditioning lines and running amperage reading of system before and after repair. 
• Warranty. 
• Pay with a credit card. If you are dissatisfied with the work, you’ll have the option to dispute the charge under the Fair Credit Billing Act. 

If You Need New Equipment… 

If your equipment breaks down beyond recovery, you’ll want the best possible price on the highest quality replacement. If you want to add central air conditioning or extend a heating or cooling system, it is even more important to make the right decisions. 

How well a new system performs, and how much it costs, will depend heavily on how carefully you think through the design. Some of the same issues also arise if you are only replacing a major component, such as a condenser unit. 

Invite several companies to your home to offer written proposals. Ask each to explain whether having more than one separate heating or cooling system and more than one thermostat would be desirable, whether you’d benefit greatly from features such as variable speed blowers (see below), how ducts will be run, where and how a condenser unit and the blower will be mounted, how you’ll access equipment for maintenance and filter replacement, and other design questions. 

Good answers to these questions will affect how much noise you hear; how quickly and uniformly your home is cooled or heated; how troubled you’ll be by drafts; energy consumption; how disruptive the installation process will be; how much closet, attic, or outdoor space the system will require; how disfiguring the ducts and air supply registers will be; and maintenance. 

Figure 1—How Central Air Conditioning Works

Choosing Equipment 

Ask each company which makes and models of equipment it will use, and their capacity, energy efficiency, and sound ratings. Most companies can offer equipment at several different quality levels. Ask them to explain the pros and cons of the alternatives, and invite them to comment on their competitors’ equipment. 

Selecting the Right Size 

Make sure that the equipment you buy is the proper size for your home. Undersized units won’t efficiently heat or cool spaces, but bigger is definitely not always better. Oversized units cost more and cycle on and off constantly, thus boosting utility bills, making more noise, requiring more frequent maintenance, and dying sooner. 

The size of heating and cooling units is described as their capacity. For furnaces and heat pumps, capacity is the amount of heat a unit can generate as measured in British thermal units (BTU). For air conditioners (and heat pumps operating in cooling modes), capacity is measured in BTU but expressed as the amount of heat the units can remove. The capacity of cooling units is usually described in “tons,” where one ton equals 12,000 BTU—for example, a 36,000-BTU air conditioner is a “three-ton unit.” 

If you have added on to your home, or finished previously un-air-conditioned space, or your old equipment didn’t sufficiently heat or cool all parts of your home, companies should perform a load calculation to determine the right size of equipment to install. (If you are only replacing old equipment that had adequately heated and cooled your home, new load calculations probably are unnecessary.) 

When calculating equipment size, in addition to taking into account your home’s square footage and the size of the previous equipment, an installer’s proposal should consider the area’s climate, the home’s insulation levels, air leakage levels, and the energy efficiency of the equipment options. Companies should perform load calculations using the Air Conditioning Contractors of America’s “Manual J” to size equipment and “Manual D” for significant ductwork. 

Selecting for Energy Efficiency 

The energy efficiency of heating and cooling equipment is measured in a number of ways, depending on the type of equipment and/or its function. 

• Furnaces (both gas and oil) are rated by annual fuel utilization efficiency (AFUE). AFUE ratings for new furnaces range from 80 to about 97, higher being more efficient. The simplest way to explain the AFUE rating is to say that a furnace with an AFUE rating of 90 uses 90 percent of its fuel efficiently and wastes 10 percent. 
• The efficiency of both air conditioners and heat pumps in cooling mode is measured by seasonal energy efficiency ratio (SEER). For new central air conditioners and heat pumps, SEER ratings range from 13 to about 21, higher being more efficient. 
• The efficiency of air-source heat pumps in heating mode is measured by heating season performance factor (HSPF). New heat pumps range from 7.7 to about 10, higher being more efficient. The efficiency of heat pumps falls as outside temperatures fall, and when the outside temperature drops below 33°F or so, the energy efficiency of most new models is usually low enough to require another heat source to maintain the desired temperature inside the home. One solution is to equip the heat pump with a backup electrical resistance heater, even though this means that when it’s cold you’re heating your house with, in effect, a very large electric space heater, and your electricity bill could skyrocket. An alternative is to back up a heat pump with a furnace. These configurations, referred to as “hybrid” systems, rely on a heat pump to heat the home until it can no longer do so efficiently, at which point a furnace takes over. 
• The efficiency of ground-source heat pumps (sometimes called geothermal heat pumps, described below) in heating mode is measured by their coefficient of performance (CoP), which indicates how much more efficient the heat pump is than (not very efficient) electrical resistance heat. In cooling mode, efficiency is measured by energy efficiency ratio (EER), which is similar to the SEER measure used for conventional heat pumps. For both the CoP and EER, the higher the number the more energy efficient the unit. Ground-source heat pumps have CoP ratings ranging from 2.8 to over 5.0 and EER ratings from 13 to over 30. 

More efficient equipment costs more money. For many homeowners, concern for the environment and worries about finite energy sources are sufficient motivation to lay out extra cash, but for those more concerned with personal dollar cost three other factors sweeten the pot: lower power bills, utility rebate programs, and tax incentives. 

Since energy prices fluctuate so unpredictably, it’s difficult to predict accurately how much energy-efficient heating and cooling systems will save. But even if you calculate energy savings based on recent energy prices, you’ll probably find that you can reduce utility bills—especially heating costs—significantly by installing more energy-efficient equipment. It makes sense to calculate whether energy savings will offset the higher price of more efficient equipment. 

Doing this math isn’t easy. Every home is different, and any formula has to take into account the size of the area to be heated and/or cooled, insulation levels, temperature settings preferred by occupants, whether a programmable thermostat will be used, and other factors. It is possible to perform these calculations using available software after entering a lot of details—more work than most contractors providing free installation estimates are willing to do. 

Contractors can help by estimating what percent off utility bills you’ll save with various types and models of equipment, for example, Furnace A versus Furnace B. You can then add up your energy bills for the year and figure out how much you’d save with each unit. Ask highly rated companies to provide these estimates and then compare claims you get, asking for clarification when they provide conflicting information. 

Be wary of salespeople who use calculators to provide on-the-spot dollar-figure savings: These estimates are often overly rosy. Heating and air-conditioning manufacturers enthusiastically provide contractors with handy formulas and devices that dramatically overstate the case for upgrading to more efficient equipment since doing so means more customers are likely to replace older equipment with new equipment—the most expensive new equipment—rather than repairing what they have or opting for less expensive new models. If an estimate of annual savings seems too good to be true, it probably is. 

If you’re uncomfortable with ballpark estimates and want to know exactly how much you’d save by spending an extra $1,000 on a more efficient unit, several software tools can estimate these savings. While you practically need a degree in engineering to operate some of them, others are quite user-friendly, and some can be downloaded or used online for free. 

One free tool is Home Energy Saver (hes.lbl.gov), a program of the Lawrence Berkeley National Laboratory. It should be noted, however, that Home Energy Saver currently does not calculate costs for hybrid-heat-pump systems or ground-source heat pumps, an unfortunate gap because for many area residents these designs may be the most energy-efficient solutions. 

Another software program we like is Architectural Energy’s REM/Design (www.archenergy.com). The software costs $347 to download, but as of this writing, a full free 90-day demo version was available for download. It was one of the few software programs we could find that wouldn’t require an MIT grad to show you how to use it that could perform accurate, meaningful analyses. 

On Table 2, we show you, for an illustrative home in the Washington area, the options a homeowner might consider when confronted with a $1,000 furnace repair—from repairing the furnace and retaining old air-conditioning equipment until it requires replacement, to replacing both units with minimally energy-efficient equipment, to replacing both units with equipment with greater energy efficiency. 

We estimated costs under each option for six years, 12 years, and 18 years (18 years is a typical projected lifespan of most furnaces, air conditioners, and air-source heat pumps). For each period, the table shows the costs of new equipment (minus available federal tax credits) plus costs for energy. The costs for equipment are prorated over an 18-year expected lifespan. We estimated the energy costs based on recent utility costs, and equipment costs based on our estimates of what lower price contractors charge. Please note that cost figures don’t take into account inflation or forgone interest on money invested in equipment. 

For each of the assumptions shown on Table 2, we have estimated that the lowest cost option (other than the very-high-investment ground-source heat pump option) looking out six years, 12 years, or 18 years would be to replace the existing furnace and air conditioner with a hybrid system that uses a high-efficiency air-source heat pump backed by a gas furnace. That would save this particular household over $2,500 compared to any of the other options over 18 years and over $700 over six years. 

Table 2—Impact of Equipment Selection on Future Costs for an Illustrative Home

Comparing some of the other options, we see— 

• A homeowner who didn’t want to invest a lot of money in a new furnace and heat pump should upgrade the furnace rather than repair the old one. Moving from an old furnace with a 72 AFUE rating to a new one with a 95 AFUE rating would save the homeowner about $318 per year, or $1,908 over six years, in heating bills and avoid the estimated $1,000 cost of repairing the old furnace—a total savings of $2,908, compared to about $3,850 for a new furnace. And prorated over an expected lifespan of 18 years, the six-year portion is $1,283. Spending a prorated $1,283 on a new furnace seems like a pretty good way to save $2,908—even given the uncertainties about the various assumptions in our estimates. 
• A homeowner who was replacing only heating equipment, and wanted to consider options other than heat pumps, should think about spending more for a high-efficiency 95 AFUE furnace upgrade rather than the least efficient furnace currently available (80 AFUE). Including the federal tax credit, the extra cost for the more efficient furnace would be $1,750. The energy savings from the more efficient furnace compared to the less efficient one would be $188 per year, or $1,128 over six years, $2,256 over 12 years, and $3,384 over 18 years. 
• If replacing only an air conditioner, it doesn’t necessarily make sense to buy a more energy-efficient model than a basic model. In our example, the homeowner would have to pay $1,100 extra to upgrade to a SEER-17 air conditioner instead of the minimum available SEER-13. The energy savings with the more efficient equipment compared to the less expensive equipment would be $62 per year, or $372 over six years, $744 over 12 years, and $1,116 over 18 years. 
• A ground-source heat pump would provide the lowest annual heating and cooling bills. Total annual energy costs for a typical model were only $615 per year. Although these systems are extremely expensive to buy and install—typically $30,000 or more because of the incredible energy savings, hefty tax and utility company incentives (the federal tax credit is 30 percent of the cost of the equipment and installation), and estimated lifespans (reflected in our calculations) about twice those of conventional equipment, it makes financial sense to consider them. 

A few additional but important points: 

• When comparing models, it’s important to understand that features such as variable-speed blowers and two-stage burners that reduce energy usage won’t be reflected on their models’ efficiency ratings because ratings are determined while equipment operates at full capacity. A variable-speed blower, for example, usually runs at a constant low speed to maintain the correct temperature, increasing speed and energy use only as needed. If you are comparing the energy efficiency of two different units with similar energy-efficiency ratings, one with variable-speed capability and the other without, the one that can run at variable speeds will use less energy. The same is true when comparing furnaces that have one- or multiple-stage burners. 

The problem is that it’s difficult to assess exactly how much energy these features save. A reasonable rule of thumb is to assume that two-stage burners and variable-speed blowers each decrease furnace energy waste by about 10 percent and increase corresponding SEER/HSPF ratings by 1.0 to 1.5. 

• Investing $5,000 extra in ultra-efficient equipment makes no sense if your home is drafty or poorly insulated, or your thermostat is pegged on Tahiti during the winter months. Before upgrading your equipment, make sure your attic is well insulated. Our article on home insulation will help get you started. And consider hiring an energy auditor to help you find and reduce air leaks. Ultimately, the best way to cut home energy costs is the most obvious one: Dial down your thermostat, and get and use a programmable thermostat. 

Our estimates on Table 2 take into account potential savings from federal tax credits for installing energy-efficient equipment. Through 2013, the credit is $150 for installing a furnace with an AFUE rating of 95 or higher, and $300 for installing an air conditioner or heat pump with a SEER rating of 16 or higher. (You can’t get the credit if you’ve used it in previous tax years on another energy-efficiency improvement.) 

You might also be eligible for rebates or incentives from your local government. Some utility companies offer financial incentives to install high-efficiency equipment. These programs vary from utility to utility; many are special loan programs. Most programs keep paperwork to a minimum, but may require you to deal with a company from the utility’s “approved contractor” list. 

An excellent resource on incentives for all types of energy-efficiency solutions is the Database of State Incentives for Renewables and Efficiency (dsireusa.org), an up-to-date database of what’s available nationwide. 

Selecting Quiet Equipment 

The sound rating of equipment is measured in bels or decibels, with lower ratings being quieter. Compared to equipment made 15 years ago, almost all new units are astonishingly quiet. 

Selecting Dependable Equipment 

Neither Consumer Reports nor any other organization systematically rates the reliability and durability of furnaces, central air-conditioning systems, or heat pumps (although Consumer Reports does evaluate room air conditioners). 

Since so little available data compares the quality of heating and air-conditioning units, your best bet for getting trouble-free equipment is to solicit bids from several contractors with good reputations for customer satisfaction. It is widely agreed in the industry that the quality of equipment is much less important than the quality of its installation. As one contractor told us, perhaps with a bit of hubris: “It just doesn’t matter too much. If I take the time to install the equipment properly, I can put in the biggest piece-of-junk furnace and make it hum for 20 years.” 

Keep in mind that customers aren’t likely to be satisfied with equipment that breaks down often—even if the companies fix it promptly. And companies committed to satisfying their customers by making prompt repairs under installation warranties aren’t going to continue installing equipment that requires frequent service visits. 

Getting a Good Price 

Based on what you learn from discussions with several companies, tell each company exactly what you want done. Then ask them to revise their proposals to respond to your exact specifications with quotes for fixed-price contracts. 

Getting competitive bids on installation or replacement jobs is a very easy way to save money. For large installation jobs, with large price variations between bids, it’s common to save $2,000 or more on a $10,000 job by getting second and third bids. 

Even for smaller installation jobs, company-to-company price differences are large. Table 1 shows the difference between the highest and the lowest price quotes for four jobs we shopped. On all four jobs, the highest price was more than double the lowest price. 

Our consumer surveys indicate that even for jobs that cost more than $2,000, more than 40 percent of consumers get no competitive bids and only about 25 percent get at least three bids. For $1,000 to $2,000 jobs, nearly 60 percent get no competitive bids. These consumers are passing up some easy money. (Remember that money saved is better than money earned because you don’t pay taxes on the money you simply avoid spending.) 

The price index scores on our Ratings Tables will help you select companies likely to make reasonable bids. But these price index scores are at best only a starting point. Many companies that charge relatively high prices for one job can come in relatively low on others. Don’t rule out a company with a high price index score if it does well on quality measures. 

Setting the Terms 

In addition to the price and a description of the equipment to be installed and the work to be done, each contractor’s proposal should include other elements, all of them important in your choice on the best outfit for your job. 

Performance Guarantee—Ask the contractor if it will give you a performance guarantee. For a complete heating and cooling system, the contract might say: “When the outside temperature is 85°F and six persons are inside, the inside temperature can be maintained at 78°F or cooler; when the outside temperature is 40°F, the inside temperature can be maintained at 75°F or higher.” 

Also request a guarantee covering the uniformity of temperature. On a hot day, you don’t want to lower the temperature of some rooms to 65°F to get other rooms down to 78°F. If you are having ductwork installed, companies should be willing to guarantee that “all rooms on the same floor can be maintained within a range of 5°F.” It’s more difficult to make promises on floor-to-floor temperature variation unless you’re installing a separate system for each floor. 

Installer’s Warranty—The installer’s warranty should say: “In case of any defects in equipment or workmanship, or any failure to meet performance specifications, we will provide without charge all parts and all labor to exchange, repair, or adjust any components installed by us for a period of one year from date of startup.” You can try to negotiate for more than a one-year warranty, but it won’t be easy because contractors will insist that most installation defects show up in the course of one full heating or cooling season. But one reason to argue for a longer warranty is that the weather in some years tests a system harder than in others. 

Payment Schedule—Make sure you get a contract that requires no payments until the work is complete, and ask if you can withhold payment until you’ve had a chance to run the system for a few weeks (this arrangement is not typical). 

If a contractor will accept full payment only after the job is complete, it tells you several things. First, the company is confident that it can satisfy you. Second, you will be able to prod the contractor to make things right if you are not satisfied. Third, the company is not living from hand to mouth—it is at least financially secure enough to procure equipment and make payroll without needing their customers’ payments. Finally, you’re protected if the company goes belly up. 

If possible, make all payments by credit card. If you are dissatisfied with the work or the equipment, you can dispute the charge under the Fair Credit Billing Act. 

Insurance Coverage—Ask every company you are considering for a certificate of insurance indicating that it carries worker’s compensation coverage for workers injured while working on your property (otherwise you could be liable). Also, get evidence of liability insurance, so you’ll know the company can make good if, for instance, it drops an air-conditioning unit through your ceiling. 

Additional Work Specifications—Go over the details of exactly what work is to be done—we have seen excellent contracts running eight pages or longer. Make sure each company’s proposal (and the contract you finally sign) is explicit about these responsibilities: 

• Providing needed electrical supply and hooking up your system to your existing electrical panel; 
• Providing drainage for condensate; 
• Providing equipment support (a base for an outside condensing unit, for example); 
• Securing all required permits; 
• Enclosing ductwork, finishing, and painting; 
• Patching holes; 
• Removing trash and old equipment. 

Get It in Writing! 

Once you have settled on all the terms of an installation job, have them written up in a firm fixed-price contract. Our consumer surveys found that for jobs that cost over $2,000 more than 10 percent of customers fail to get such contracts, and for $1,000 to $2,000 jobs more than 30 percent fail to document the deal. That is playing with fire. 

Making Your Stuff Last 

The most important maintenance task for both heating and cooling systems is something you can do yourself—replacing the air filter. With a new system or one in a home you’ve just moved into, check your filter monthly until you see how quickly it gets dirty at different times of the year. You will probably need to replace it two or three times during the cooling season and equally often during the heating season. When a filter has a matting of dirt—i.e., it’s difficult to see through when you hold it up to a light—it’s time to replace it. If you aren’t sure how to tell when a filter is too far gone, ask your technician to show you what to look for during the next service visit. 

A dirty filter makes your system work harder than it should, reducing performance and energy efficiency. A dirty filter also makes your system spread dirt throughout your house. An extremely dirty filter can be especially bad for heat pumps and air-conditioners, since it can cause evaporator coils to freeze up and, possibly, cause the compressor to fail. 

Air Conditioner/Heat Pump 

One task you can do yourself for either an air conditioner or a heat pump is to clear debris away from the outdoor unit. Keep the unit’s grills free of grass clippings, leaves, and other debris which can inhibit airflow. Through the winter months, clear away snow that accumulates around the outdoor unit of a heat pump. If snow regularly drifts in banks around your unit, check your owner’s manual to see if your unit has been installed to manufacturer’s specifications. Typically, outdoor units should be installed atop a platform several inches above ground level. If not, have a contractor raise your unit. An obstructed outdoor unit overworks the compressor and can cause a costly premature failure. 

Other maintenance tasks are usually performed only by professionals. Condenser coils need to be checked for surface dirt and dust, and cleaned if necessary; contractors often use a special chemical bath for the cleaning. Electrical connections and contacts need to be checked visually, and capacitors should be tested. Controls designed to protect the compressor from high or low pressure should also be tested. Finally, the refrigerant level should be checked, with refrigerant added as necessary. 

Under no circumstances add or release refrigerant yourself. As part of U.S. Environmental Protection Agency regulations written to comply with the international ban on ozone-depleting substances, all heating and air-conditioning contractors that handle refrigerant must be trained and certified, and they must possess equipment that will capture the refrigerant and prevent it from escaping into the atmosphere. 

Proper maintenance enhances your equipment’s performance, energy efficiency, and durability. If you do the tasks you can do yourself, however, it’s not clear how much benefit professional maintenance service provides. 

Contractors will argue in favor of air conditioner maintenance visits each spring before the cooling season, and heat pump visits each fall. But heating and air-conditioning contractors have an obvious bias: the more visits you pay for, the more money they make, and the better their equipment runs. Best of all from the contractor’s standpoint, maintenance visits take place before peak heating and cooling seasons, providing a welcome flow of revenue and a way to keep technicians busy. 

Equipment manufacturers have less reason than contractors to endorse maintenance visits. Although regular maintenance may make manufacturers look good by helping equipment achieve maximum lifespan, performance, and efficiency, a manufacturer can look even better by claiming that its equipment can do without expensive maintenance. Nonetheless, most manufacturers recommend annual professional maintenance of air-conditioning and heat pump systems. 

Yet there appears to be little hard data indicating that reductions in energy use or increases in equipment life offset the cost of professional maintenance. Clearly some systems run well despite forgoing years of professional maintenance. And contracting for yearly maintenance visits for air-conditioning equipment, for example, seems rather arbitrary. Why not twice a year, or once every two or three years? Why not more or less often depending on conditions? It is clear, for example, that the need for maintenance is greater if your system is old, heavily used, has much dust and pollen around it, has aluminum wiring, or frequently breaks down. Also, maintenance is more justified in large houses where a small percentage improvement in energy efficiency can produce substantial savings. 

In the end, the decision on professional maintenance will be much like decisions about how often to change your car’s oil or have your teeth cleaned: There is no absolute right answer. As with those decisions, ask the professional you deal with to explain why a particular maintenance interval is right, given your individual circumstances. 

If you don’t plan to have yearly professional air-conditioner or heat pump service, test your system before the usage season begins. That way, if there is a problem, you can order a service visit before the peak-season rush. 

Gas and Electric Furnaces 

Gas and electric furnaces usually need less professional maintenance than other types of equipment. But it can be worthwhile to have a professional visit every year or so to clean and adjust your equipment for the sake of efficiency, and check for existing or potential leaks of fuel or combustion products. 

Oil Furnaces 

An oil-burning furnace is the piece of equipment most likely to need regular preventive maintenance. Replacing nozzles and oil filters, adjusting excess air levels, and cleaning soot from the firebox can increase heating efficiency by 10 to 12 percent—even more in badly maintained systems. Find an expert who has the equipment and knowhow to measure carbon dioxide, flue gas temperature in the stack, “smoke number,” and the stack draft to do this maintenance. Have the expert also check for dangerous smoke leaks and improper safety shutdown. 

If you have a large house, where a few percentage points improvement in oil furnace efficiency would save the cost of a service visit, arrange for a professional to visit annually. But if your house is small, you can skip a year or two between visits. 

Getting a Good Price 

It’s not difficult to compare prices for maintenance-only service visits. Call companies that rate high for quality on our Ratings Tables and ask their price for a maintenance-only service visit assuming no repairs will be needed. Find out exactly what is included in maintenance service. (Will they clean condenser coils, for instance?) Expect to pay between $75 and $125 per visit. But bear in mind that maintenance visits sometimes reveal the need for repairs, so use a high-quality company that charges reasonable prices. 

Extra Advice:
Equipment Features to Consider 

If you are installing new equipment, in addition to making choices about energy efficiency, you will need to decide whether to pay extra for various features. Below is a summary of the types of add-ons. We’re admittedly scratching the surface of the heating-and-cooling-equipment options world here, but these are the major “do you want this or not?” questions you’ll face. 

• Variable-speed blowers—Indoor fans (blowers) and/or outdoor fans of central air conditioners, heat pumps, and furnaces can be equipped to run from slow to fast depending on need. The units are programmed to keep conditioned air continually moving at the lowest flow possible. These setups minimize cycling on and off (which contributes to wear and tear), dramatically help systems maintain consistent temperatures throughout different areas of homes, reduce energy usage, and decrease noise. 
• Variable output—Furnaces with this feature automatically select how much heat to generate (usually from among two levels); air conditioners and heat pumps with variable output automatically select how hard their compressors need to work to deliver conditioned air. Like variable-speed blowers, this feature lets equipment deliver warm or cool air continuously for longer periods of time, meaning equipment doesn’t have to cycle on and off frequently. 
• Programmable thermostats—These devices provide an easy way to save energy, as long as you actually program them (which most homeowners who have them don’t). If your home is unoccupied during the day, you can save five to 15 percent per year on energy bills by turning down the heat by 10F° to 15F° while you are away. Obviously, you’ll want to get a model that is easy to use. A misconception associated with programmable thermostats is that when it is time to return the temperature to normal, the furnace has to work so hard and use so much energy little energy is saved. Much research has shown this to be untrue. 
• Humidifiers—These can be added to ductwork and supplied with water from plumbing to make air more humid during dry winter months. Also, at the same temperatures, humid air feels warmer than dry air—which means you can dial down your thermostat by a few degrees and not notice the difference. Avoiding overly dry air reduces itchy skin, eyes, and throats, and helps asthma sufferers. 
• High-efficiency air filters—These assemblies, which use electrical charges to attract and trap particulates, can also reduce the amount of dust blown through systems. But there’s little evidence that they actually improve indoor air quality. 
• Scroll compressors—This is a relatively new advance in heat-pump technology that replaces regular piston-type compressors with two spiral-shaped scrolls. One scroll remains stationary while the other orbits around it, compressing the refrigerant by forcing it into the smaller space. The benefits of heat pumps with scroll compressors include longer operating life, less noise, and the ability to deliver conditioned air 10° to 15°F warmer than conventional heat pumps. 
• Desuperheaters—Some high-efficiency heat pumps can be equipped with these devices that capture waste heat generated from heat pumps during cooling mode and use it to heat water. Desuperheaters heat water two to three times more efficiently than conventional electric water heaters. 

Extra Advice:
Service Contracts 

Rather than paying for individual maintenance visits and repair jobs, you might consider getting a service contract for air-conditioning and/or heating equipment. Many companies try to persuade customers to enter into such contracts. 

If you are interested in a service contract, compare the price and coverage of various contracts. (And stay aware of repair prices because most service contracts have many coverage gaps.) 

Service contracts fall into three broad categories: 

• Contracts covering only the labor cost of usually either annual or semiannual planned maintenance visits to check, clean, and adjust equipment. 
• Contracts covering the labor costs for planned maintenance visits and for unplanned repairs. 
• Contracts covering labor costs for both maintenance and repair visits and costs of selected parts. 

Within these categories, coverage varies. First, there are contracts for furnace only, for air-conditioning equipment only, and for the two combined. Second, some contracts cover work that others exclude. Among maintenance-only contracts, the most common exclusion is the cost of cleaning air-conditioning coils. Among contracts covering labor and/or parts for repairs, exclusions range from such costly work as replacing a compressor to much less expensive items like capacitors. Request copies of the contract forms for any company you consider. 

The differences in contract prices are striking. For example, the cost of one level of coverage for one year ranged from $100 to $300 among companies we compared. 

To compare the value individual outfits offer, look at companies that cover roughly the same items. Also, check what companies do on maintenance visits—do they clean the air-conditioning coils, for example? And keep in mind that some companies may offer 24-hour service while others are hard to reach outside regular business hours. 

You’ll probably do better by not buying a service contract and footing repair and service bills each time you need it. But there are three main reasons to buy a service contract— 

• To perform preventive maintenance; 
• To get priority service when your equipment breaks down; and 
• To insure against the costs of sizable repairs (to the extent that repair costs are covered). 

Some companies swear by these contracts, arguing that they facilitate efficiency by allowing them to schedule work when demand is low, thus letting them avoid paying overtime during peak load periods and employing excess personnel to prepare for peak demand periods. Other companies say contracts are little more than ploys their competitors use to ring up extra profits at your expense. They insist that service contracts waste your money and a company’s time by encouraging unneeded maintenance visits and emergency calls. There’s some truth in both views. The right answer for you depends on your circumstances. 

If you need professional maintenance visits every year—if, for instance, you have a large house or don’t want to perform even the simplest maintenance tasks yourself—a service contract may be right for you. But don’t pay more for the contract than you would pay for the number of visits it includes at regular labor rates. 

If you need maintenance visits less than once a year, paying for them one-at-a-time may work for you, and the only reasons to get a service contract would be to get priority service on unscheduled repair calls or as insurance for costly repairs. (Unfortunately, local services seldom offer these protections unless you pay for maintenance visits as well.) But these protections may not be worth the price of a service contract. 

Priority treatment on unscheduled repair visits may be especially important if someone in your home has serious allergies or frail health, if you have valuable houseplants, or in other special circumstances. Even so, getting a service contract may not protect you. Furnaces and air conditioners most often break down when the weather is extreme, and companies simply lack sufficient staff to handle the demand. Although they do put their technicians on overtime and send supervisors into the field, sometimes they just can’t keep pace—even for their priority customers. 

In fact, one of the most common complaints we receive from readers is waiting weeks to get an appointment for repairs from companies with which they have signed service contracts. For quick service, you might do just as well without a service contract. Whenever you need repairs, call a few companies and hire the one that will come soonest. 

If your objective in getting a service contract is to insure against expensive repair bills, check the price of any contract that offers that level of protection. And remember: The most costly repairs—replacing compressors and heat exchangers—are not covered by most service contracts. 

A final important point: If you want a service contract, take care in choosing the company. We get a lot of complaints from consumers who buy service contracts and find that technicians discover something to repair on every service visit—at extra cost. Some contractors seem to use service contracts as twice-a-year opportunities to squeeze customers for unnecessary repairs. 

Extra Advice:
Ground-Source Heat Pumps 

Conventional heat pumps work in heating mode by drawing heat from outside air. During the heating season when air outside is colder than the air inside the home, heat pumps draw warmth by blowing outside air over refrigerant-filled coils. The refrigerant in the coils absorbs available heat as it converts from liquid state into vapor. The vapor is then circulated into another set of coils inside the house and compressed into a liquid, a process that makes it hotter. A fan blows air over these relatively hot indoor coils, thus warming the air and cooling the refrigerant. The warmed air is distributed through the home. The cooled refrigerant is circulated back outside, the pressure on the refrigerant is released, and the refrigerant is again vaporized, drawing warmth from the outside air. The cycle keeps repeating itself. Air conditioners, or heat pumps working in cooling mode, operate the same way except the process is reversed. 

New heat pumps are remarkably efficient when outdoor temperatures remain above 33°F or so. In cooler weather, conventional heat pumps can’t draw enough warmth from the outside air to keep the indoor space conditioned. When this happens, a secondary, less energy-efficient source of heat must be used. 

Ground-source heat pumps (also referred to as geothermal heat pumps) employ the same general technology as air-source heat pumps (conventional units), but don’t rely on sometimes-too-cold outside air as their source of heat. Instead, they draw upon stable below-ground temperatures to provide the warmth absorbed by vaporizing refrigerant. If you’ve ever toured a cavern, you probably were informed that its temperature stays the same year-round. The same is true of temperatures just a few feet below the surface. Depending on the region, temperatures remain a fairly constant 45° to 75°F. 

Instead of passing outside air over refrigerant-filled coils, ground-source heat pumps draw the heat absorbed by vaporizing refrigerant by passing the refrigerant through coils, or a system of pipes, buried below ground. 

Since ground-source heat pumps don’t require alternative sources of heat during cold weather, and can more efficiently create warm air from their warmer surroundings, they can be incredibly energy efficient. We estimate that a typical ground-source system used for the illustrative home shown on Table 2 would cost only $791 per year in energy costs to operate—by far the lowest cost option. According to the EPA, geothermal heat pumps can reduce energy consumption—and corresponding emissions—up to 44 percent compared to air-source heat pumps, and up to 72 percent compared to electric resistance heating with standard air-conditioning equipment. 

But you’ll have to pay a lot more upfront to get these savings: A ground-source heat pump system can cost $30,000 or more. The reason for the big price tag isn’t so much the equipment (about twice as much as comparable air-source equipment) as the high cost of installation. The coils for air-source heat pumps take up relatively little space because fans blow air over the coils. But in order to draw warmth from below-ground temperatures, ground-source systems need to send refrigerant long distances, which means coils or pipes must be buried in a way that requires a lot of labor-intensive digging or drilling. 

The most common setup for a ground-source system is a closed-loop system, which requires digging horizontal trenches about four feet deep and burying a series of pipes or coils. Or it can be done by drilling a series of vertical holes 100 to 300 feet deep and inserting connected pipes. Because installation costs are so high, even if you could buy and install a ground-source system for a bargain-rate of, say, $20,000 it would still take a long time to recoup the upfront costs through energy savings. But there are other factors to consider in the calculus. 

First, Energy Star-certified ground-source systems qualify for a 30 percent federal tax credit for the entire cost of the project, including installation. Credits, rebates, and/or incentives may also be available from local governments and utilities. 

Second, ground-source systems are usually equipped with desuperheaters, which create virtually free hot water during the summer and relatively inexpensive hot water during the winter (see above for more information on these devices). This means a ground-source heat pump might save some households $150 or more per year in energy costs compared to using a gas water heater, and $300 or more compared to using an electric heater. 

Third, ground-source heat pumps require much less maintenance than conventional equipment and don’t need to be replaced nearly as often. 

Ground-source systems are well-suited for newly constructed homes for several reasons: You avoid ruining landscaping by installing horizontal systems; digging and drilling is cheaper because that work can be coordinated with other required digging; and you can spread out paying the higher upfront price by taking out loans. One promising approach to designing new, energy-efficient homes would be to build underground piping that all the homes in the community could share. But most developers won’t take on the expense of building homes or entire communities that use ground-source systems. In the future, more may be compelled to do so. 

We won’t try to calculate the cost effects of a ground-source system spread across a 30-year mortgage. But paying monthly across 30 years for the system immediately begins to generate a positive cash flow, improving affordability.