In general, there are four types of central air conditioning: Split systems are the most common type of central air conditioner found in the U.S. Inside the house, tucked in a cabinet, is the evaporator coil, which removes heat and moisture from the air. Outside the house, a metal case contains the condenser coil, which releases the heat, and the compressor, which pumps refrigerant between the two coils. The indoor component of the air conditioner is connected to a network of ducts, and a blower circulates the cold air through them to reach all parts of the house. This type of system is the most economical to install in a house with a central furnace, because it can share the ductwork used by the heating system. All of the central air conditioner systems in this report are split systems. Heat pumps are a variation of the traditional split system. During hot summer months, it pumps heat from the house and releases it outside. In the wintertime, it extracts heat from the outdoor air and uses it to warm the house.

Because of that, heat pumps can be used effectively for both heating and cooling in mild climates. However, heat pumps do not generally work well when temperatures stay below freezing for a long time, so they are not the best choice for cold climates. A specialized type of heat pump, called a ground-source or geothermal heat pump, could be an option for colder environments. It works by drawing heat out of the ground rather than the air. -- and not every contractor is familiar with or capable of doing the installation. Packaged central air conditioners combine the evaporator, condenser and compressor in a single unit. The air conditioner is usually placed on a roof or a concrete slab near the foundation. Ducts running through the exterior wall or roof draw air from inside the house and return cooled air indoors. This type of air conditioner can also be used in small commercial buildings. When combined with a set of heating coils or a natural gas furnace, it eliminates the need for a separate furnace inside the building.

Ductless mini-split systems can be a good choice for houses that do not have ductwork. Like a basic split system, the ductless mini-split combines an outdoor compressor and condenser with one or more indoor air-handling units. These units are mounted high on the wall and have blowers attached. Tubing connects the indoor and outdoor units and circulates refrigerant between them. Each indoor unit is installed in a separate room and cools that room only, much like a window air conditioner. The main advantage of ductless mini-split systems is that they can be installed without tearing up walls to install ductwork. They also allow the flow of cold air to be controlled independently in each room (or shut off altogether in empty rooms). If used to cool an entire house, mini-split systems are more expensive than ducted central air conditioning systems, costing roughly 30 percent more for the same amount of cooling power. However, they are also more efficient, since they avoid the energy loss associated with ductwork.

When comparing central air conditioners, one term you'll see repeatedly is the seasonal energy efficiency ratio (SEER), a measure of how much energy the air conditioner uses to cool a home. york ac service manualCentral air conditioners range from 13 to 28 SEER. air conditioning unit small officeThe SEER is calculated by taking the total cooling output over the course of a summer, measured in British thermal units (BTUs), and dividing it by the total amount of energy the air conditioner uses over that same period.water cooled ac unit for sale These figures are based on a theoretical average climate for the United States. In reality, of course, the same air conditioner's performance may vary considerably based on how hot and humid it is outdoors.

SmarterHouse, a project of the American Council for an Energy-Efficient Economy (ACEEE), recommends that people who live in hot and humid climates choose an air conditioner with a SEER of at least 15. They also note that if you have an older system with a SEER of 10, upgrading to a model with a SEER of 15 could cut your air-conditioner energy costs by a third. Another measure of air conditioner efficiency is the energy efficiency ratio (EER). This measures the air conditioner's efficiency at any given moment. It's simply the cooling capacity of the air conditioner, as measured in BTU per hour, divided by its energy consumption in watts. Energy Star ratings for central air conditioners are based on both SEER and EER. To qualify for the label, a standard split-system central air conditioner must have a SEER of at least 14.5 and an EER of at least 12. For single-package units, the requirements are lower: 14 SEER and 11 EER. The Energy Star label is only one award a central air conditioner can earn for efficiency.

The Consortium for Energy Efficiency (CEE) goes beyond the Energy Star ratings by defining three additional tiers for super-efficient models. A CEE Tier 0 unit is one that meets the Energy Star criteria. Tier 1 split central air conditioners have a minimum of 15 SEER and 12.5 EER, Tier 2 air conditioners have a minimum of 16 SEER and 13 EER, while the Tier 3 specification is a minimum of 18 SEER and 13 EER. State and local governments, as well as utility companies, may offer rebates for choosing a central air conditioner that meets one of these higher standards, so check those to get the best bang for your buck when buying a new central air-conditioner system.Most heating and air salespeople will tell every customer they need to install an ultra high efficiency (and ultra-expensive) central air conditioning unit. The truth is, very few people actually need such a high-end unit. Even many homeowners who ultimately decide to install a 16 SEER (or higher) air conditioner don’t technically need such an ultra efficient unit to cool their homes comfortably.

They install them because other considerations can sometimes make upgrading beyond a basic model a no-brainer financially, Don’t get me wrong, I’m not against ultra high efficiency air conditioners. Quite the contrary, I think they’re fantastic. What I am against is salespeople misleading customers in order to sell more expensive equipment just so they can earn higher commissions. So I’d like to arm you with the information that will help you decide 2 things for yourself… Let’s start with this basic premise… when sized correctly, even the most basic 13 SEER air conditioning unit will cool your home. Despite what any salesperson tells you, a 13 SEER unit will cool just about any home comfortably.This may come as a surprise, but installing a new air conditioner is not high on most people's list of fun ways to spend money. So why not install the air conditioner that makes the most sense for you and your home financially? People who live in larger homes and older homes, especially if they have 2-story ceilings or lots of windows, will usually find it very expensive to keep their home comfortable during the summer.

If your utility bills are high enough, you might want to consider a 16+ SEER ac unit. This is especially true if you are replacing your old air conditioner and furnace at the same time so you can potentially qualify for a rebate from Xcel Energy. A 16 SEER air conditioner is approximately 20% more efficient than a basic 13 SEER unit. A 17 SEER model would be about 30% more efficient than a basic 13 SEER unit, so you can expect to lower your summertime utility bills a good bit by upgrading to one of these ultra high-efficiency air conditioners. it’s worth spending the few minutes it takes to do a rough calculation to see how long it will take to recoup back the additional money you spend on an ultra high efficiency air conditioner. Just multiply the increase in energy efficiency (use .20 for a 20% increase for example) amount of your average summertime utility bill. Then multiply the amount you would expect to save each month during the summer by 4. (4 being the number of months that are hot enough to need your air conditioner every day here in Denver)

That will give you a good estimate of your annual utility bill savings with a higher efficiency air conditioner. Say you would save about $300/year by installing a 16 SEER unit instead of a 13 SEER. If the cost difference after any Xcel Energy rebates is $1,500, it would take you 5 years to recover the additional cost. That’s a very reasonable time frame, and certainly worth installing the upgraded unit. If you’re just replacing your old air conditioner, you can qualify for the $500 Trade-In Rebate from Xcel to offset some of the cost of installing a more efficient unit. If you’re replacing your old air conditioner a new furnace at the same time, you can potentially qualify for both the $500 Trade-In Rebate and the New Equipment Rebate from Xcel. It’s important to keep in mind that the amount of the New Equipment Rebate you’ll actually receive depends on the EER rating of your new system, so you should think of it as being eligible for ‘up to’ the amount listed.

For example, even though the New Equipment Rebate for a 16 SEER air conditioner is listed as $500, the amount you’ll actually get back might only be $300, depending on how your new system rates out when tested for the EER. If you can qualify for both the Trade-In Rebate and at least a portion of the New Equipment Rebate from Xcel, it’s definitely worth considering a more efficient unit. If you’re looking to take advantage of a 0% Financing offer with an extended term (like 0% for 48 or 60 months), you will have to purchase a ‘qualifying system’ to get those terms. You can expect the 'qualifying system’ to include at least a 16 SEER air conditioner, and often times you’ll have to install a 17 SEER unit to qualify for the special financing. Don’t be surprised if you’ll also have to install a new variable-speed furnace at the same time to qualify for most of these financing promotions. Keep in mind that even 0% Interest financing isn’t necessarily free.