No membership or credit card requiredGet StartedNo thanks, I'm not quite ready. Insider’s Price Guide to a New Heating and Cooling SystemYou are here » » » » Heating & CoolingWith a geothermal heat pump, you can tap the clean, renewable heat beneath your feet. Although geothermal heating and cooling systems are not that well known by the public, they have a proven track record that stretches back decades. In fact, there are more than one million geothermal heat pumps in operation around the world.The technology is also called earth-coupled, ground-source or ground-loop heating and cooling, and the sector is distinct from the more familiar geothermal energy. In the latter process, engineers take advantage of hot water near the earth's surface, or inject water down into hot rocks, in order produce electricity.But you don't have to live near volcanic activity to take advantage of a geothermal heating and cooling system. All you need is to bury some pipe into the ground around your home, and a heat exchanger -- similar to the one in your window air conditioner -- will magnify the effects of the temperature gradient, producing exceptionally even, quiet heating and cooling.

There is a lot of heated debate over what climates are optimal for earth-coupled climate control systems, but in researching our recent book Geothermal HVAC, we talked to folks with many successful installations all over the world, from chilly Alaska to the scorched Southwest, and from tropical islands to the Middle East. air conditioning unit central priceA properly built geothermal system can readily provide 20 years of reliable heating and cooling, with minimal maintenance. compare portable ac unitsYou need only a small amount of electricity to run fans and controls, so you slash your carbon footprint.automotive a/c recovery unitIn our book Geothermal HVAC, my co-author, Jay Egg, crunches the numbers for a typical homeowner, based on his 20+ years in the business.

For a home geothermal system, he estimates the total installed cost at $42,000. It sounds like a lot, but the sticker price is only a small piece of the puzzle. One thing to note is that a significant chunk of that is for excavations of the ground loops, which will typically require a few thousand feet of pipe in contact with the soil. Once those bores or trenches are made, they should never have to be redone, even if the system components need replacing after 20+ years.Homeowners get some help from Uncle Sam, in the form of an income tax credit worth 30% of the total cost of a new geothermal system, including parts and labor. The credit currently expires at the end of 2016, but it has no cap, and does not have to be on a primary residence. If all the credit can't be used in a single year, it can be rolled forward. In our example, the credit is worth $12,600.With a geothermal system, the ground-loop and heat exchanger provide all the hot water your home needs, so you no longer need to pay to heat it up.

That saves an average of $500 a year, according to the DOE. If you are calculating out to 20 years, the estimated life of the system, add an average annual increase of 4% to that, to account for steadily rising utility prices.When it comes to energy savings, the first year, your system will save you an estimated $1,617, because you don't need to pay for conventional heating and cooling. Add a 4% increase to that every year going forward. Egg also points out that you can save an average of $500 a year in repair and maintenance costs, because geothermal is more reliable than conventional systems.Jay Egg reasonably points out that if you weren't getting a geothermal system, you would still need heating and cooling; a complete high-efficiency conventional system costs an average of $22,000. Subtract that from the $29,400 (the system cost of $42,000 - $12,600 tax credit), and you get $7,400, the real additional cost of going with geothermal.If you save $1,617 each year in energy and $1,000 in hot water and maintenance, the payback period would be just short of three years.

Over 20 years, Egg estimates the system could save $69,000.Of course, if you already have a competent HVAC system, your payback period is going to be longer, because you can't subtract out $22,000. But if you have new construction or have to replace an aging system, the math works. New Air Conditioning for Old Houses New Air Conditioning for Old HousesIt's now easier to retrofit older homes with increasingly compact air conditioning systems. High noon will turn many a classic home into a summertime sweatbox. And while noisy window-mounted air conditioners can lower temperatures, they are just as apt to spoil a charming exterior. Unfortunately, many old homes don’t have a convenient space to install ductwork for a traditional central air-conditioning system. Lowering ceilings or building out walls to hide supply and return ducts is expensive, and can blemish indoor spaces. Sometimes the attic or basement can hold the ductwork, but it’s still a shame to chop big chunks out  of original plaster ceilings, wood floors, or wainscoting to place air registers.

But don’t sweat it: There are air-conditioning systems that don’t need much bulky ductwork. Mini-split systems use individual cooling units placed room by room, which require only a thin refrigerant and power line connecting them to an outdoor air-conditioning compressor and fan. Another alternative, known as high-velocity systems, use two-inch insulated air-supply tubing to deliver chilled air. This tubing can be snaked through existing walls and ceilings in an old home to deliver cool air where it is needed. The registers are unobtrusive discs placed around the perimeter of the ceiling, or high on the walls. All retrofitted air-conditioning systems will require some degree of creative cutting and patching in walls, floors, and ceilings. And while the new high-tech systems cost more than a regular duct system in new houses, they save money in old homes because of the reduced need for rough carpentry and subsequent finish work. An $8,000 to $10,000 price tag isn’t unusual for a high-velocity air-conditioning retrofit in an old house.

Mini-splits offer an economical compromise: You can install cooling units in just one or two rooms, creating an oasis to retreat to during the dog days of summer. Consult a professional installer to choose an air-conditioning compressor that will allow you to expand a partial system at a later date. A properly sized air-conditioning system is the most important factor for a comfortable home. Systems that are too big or small will lead to a host of complaints—it’s too loud, it breaks down too often, some rooms are too hot, some rooms are too cold, the electricity bills are too high. A professional installer who will size the right is crucial to comfort. Make sure your installer shows you the industry-standard “Manual J” and “Manual D” sizing calculations for your house. If an installer wants to use rule-of-thumb sizing methods, find another contractor. While there are a number of factors involved in choosing an air-conditioning system, keep in mind that bigger isn’t better.