Buying a Furnace
Updated Aug 28, 2014
By Chris Brooks
Many people buy their first furnace without even realizing it. They buy a house with their furnace already installed. Many people buy their second furnace with the same amount of thought: they open their phone book and call the first HVAC (Heating, Ventilation and Air Conditioning) contractor on the list. This strategy is likely to net you a furnace that will keep your house warm. But you are also likely to spend hundreds, if not thousands, of dollars more than necessary.
How do you choose the most appropriate furnace?
Savvy furnace shoppers generally consider several criteria:
- Is your furnace correctly sized?
- Are you buying an appropriately efficient furnace?
- Are you getting the best price for your furnace?
Is your furnace correctly sized?
An oversized furnace -- one whose capacity is too large -- costs more to operate than a correctly sized furnace. This is because oversized furnaces cycle on and off too often -- and cycling on and off is more expensive (and less energy-efficient) than running consistently for a long time.
The only way to know if your furnace is correctly sized is for your HVAC contractor to do a load calculation. A load calculation takes into account the size of your house, the insulation value of your windows, the amount of insulation in your walls and roof, and a host of other criteria to determine the appropriate furnace capacity. The industry accepted standard, the Manual J, is best performed by a professional contractor who has the necessary software and experience to easily complete the task, rather than attempting this yourself.
Ask your HVAC contractor if s/he performed a load calculation before you accept the furnace they recommend. If you are replacing an old furnace (as opposed to buying a furnace for new construction) some contractors may argue that you should simply buy a furnace that's as large as your previous furnace -- but this assumes that the previous contractor selected an appropriately sized furnace. Request that they perform a load calculation, and find another contractor if they refuse.
Is the efficiency of your furnace appropriate for your house?
A furnace’s efficiency is commonly listed as its Annual Fuel Utilization Efficiency (AFUE). This rating describes the amount of heat that your furnace emits; for example, an 80 percent AFUE means that furnace will convert 80 percent of the supplied fuel directly into heat.
High-efficiency furnaces typically cost more upfront than low-efficiency furnaces. However, they tend to cost less to operate on a month-to-month basis as they use less fuel to generate the same amount of heat. The amount of time it takes for the ongoing efficiency savings to offset the higher up-front costs is known as the "payoff period". In many cases, once you take the payoff period into account, high-efficiency furnaces are cheaper than low-efficiency furnaces.
However, that's not always the case. Your 90% efficient furnace will cost you more than your 80% efficient furnace if you move to a new house within the payoff period. And, depending on which furnace you choose, the payoff period may be surprisingly long! You need to consider a number of factors such as your climate, how long you plan to own your home, and whether rebates for a high-efficiency furnace are available.
Are you paying a reasonable price?
There are several ways to reduce the cost of purchasing and installing a new furnace.
- If you are buying a higher-end, high efficiency furnace during the Spring or Fall, some manufacturers are likely to offer incentives, from low-interest financing to cash-back when installation is complete.
- Encourage several HVAC contractors to compete for your business. However, keep in mind that you rarely want to make your decision based on up-front price alone. Choosing a reputable HVAC contractor is as important in determining your overall satisfaction and cost as choosing an appropriate furnace.
- You can also negotiate the final cost of your new system. Negotiating the price of a new furnace is a balancing act. You don't want to pay too much, and you don't want to pay too little. One tool that you may find helpful in deciding whether a given contractor's price is reasonable is the 2013 Furnace Price Guide. The report lists the prices of hundreds of furnaces from 25 different brands.
- In addition, many public and private entities in the U.S. and Canada offer rebates and financing incentives for the purchase of a furnace. Energy Star furnaces may qualify for a federal tax credit. Make sure you find out whether your purchase qualifies.
While the factors listed above will be the most important considerations for your new furnace, there are other differentiators among the many available products. Depending on where the furnace will be located, you may want to select a unit that is listed as being particularly quiet; higher efficiency units may feature sealed combustion units, while multi-speed or 2-stage furnaces will be quieter than their counterparts since they can run at lower speeds. In addition, it can pay to factor the warranty into your cost considerations. Provided you maintain your furnace appropriately, a longer warranty can translate to cost savings over the long run.
Choosing a Contractor
Just as important as selecting a furnace is the need to select a qualified, licensed contractor to install it. You'll want to get estimates from at least three contractors before hiring anyone. For more tips, read through this article on selecting the best contractor for your job.
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