Find out your heating and cooling system options
The vast majority of U.S. homes have air conditioners, and 99 percent of all new homes built have central air conditioning installed as part of the residential HVAC unit. In fact, 8 percent of all energy consumption in the U.S. is for home air conditioning, and it costs homeowners above $15 billion a year. Picking a residential HVAC unit that is energy efficient is not only easier on your wallet, but it’s also kinder on the environment.
Choosing an energy-efficient & environmentally friendly heating and cooling option
The amount of electricity used every year releases roughly 196 million metric tons of carbon dioxide (CO2) into the atmosphere, which is an of close to 2 tons per year for homes with A/C.
Heating accounts for 35 percent to 50 percent of a household’s annual energy bills, which is the largest expense for most homes. Choosing an energy efficient residential HVAC unit can help reduce the amount of CO2 pumped into the atmosphere. Heating systems in the United States contribute about 12% of the nation’s sulfur dioxide and nitrogen oxides each year. Being conscientious about the heating system you place in your home can save you money and the environment too.
Understanding different types of residential HVAC units available to you will help you make the best-informed decisions possible. The following is a brief rundown on common and feasible cooling and heating options for a home. Some of these residential HVAC units have been around for generations and some are state-of-the-art HVAC tech.
Central air conditioning and heat pumps
Central air conditioners and heat pumps are residential HVAC units that cool the entire house. Each system has a large compressor unit located outside, driving the process. The indoor coil is filled with refrigerant and cools air that is then distributed through ductwork into the home. Heat pumps are similar to central air conditioning, however, the cycle can be reversed and used for heating during the winter months.
Room air conditioners/Window units
Window units are single room air conditioners and are sized to cool one room only. Several of them will be required to cool an entire home. They are typically mounted in a window, but can also be mounted through a wall. Regardless of how you decide to mount them, the compressor is located outside. Individual units cost less to buy than central systems, and pricing varies depending on BTUs and quality. Below is a chart to help you find the correct sized window air conditioner unit for your home. Too small and it won’t cool, too big and it’s wasting money and energy.
|Federal Standard min EER||ENERGY STAR min EER|
|Capacity (Btu/Hr)||as of Oct. 2014||as of Oct. 2014||As of July 2017|
|less than 6,000||11.0||11.2||12.1|
|6,000 to 7,999||11.0||11.2||12.1|
|8,000 to 13,999||10.9||11.3||12.0|
|14,000 to 19,999||10.7||11.2||11.8|
|20,000 to 24,999||9.4||9.8||10.3|
|25,000 or higher||9.0||9.8||9.9|
Evaporative cooler/Swamp cooler
Evaporative coolers, which are often called swamp coolers, are not nearly as common as central air conditioners, but they are a practical and cheap alternative in very dry areas, like the Southwest. They cost about half as much to run as a central air conditioning unit and are cheaper to install too. They work by pulling fresh outside air through moist pads where the air is cooled by evaporation. The cooler air is then circulated through the house. It’s not a dissimilar process to when you step out of a swimming pool and you are chilled by a breeze even on a hot day.
Ductless mini-split air conditioner
Mini-split air conditioning systems are very popular in other countries and are often used in the U.S. to retrofit rooms that have no ductwork because they are additions, older homes, or homes with radiant flooring.
Mini-splits use an outside compressor and condenser and indoor air handling units like central air conditioning; however, the difference is that each room to be cooled has its own air handler so that it can be zoned individually. Each indoor unit is connected to the outdoor unit by a conduit carrying the power and refrigerant lines. The indoor units are usually installed toward the top of a wall near the ceiling.
Night Breeze is a state-of-the-art HVAC cooling technology. It saves energy in hot, dry climates, and is basically a whole-house fan, central A/C, and indirect water heater all rolled into one. During the summer, the system draws in as much cool outdoor night as possible — the air conditioner only runs when absolutely necessary. During the winter, it can provide heat using the home’s hot water system.
Most homes in North America rely on a furnace to provide heat. A furnace blows heated air through a home’s ducts to deliver warm air to rooms throughout the house via air registers. This type of heating system is called most commonly known as forced air distribution. It can be powered by electricity, natural gas, or fuel oil.
Inside a gas- or oil-fired furnace, the fuel is mixed with air and burned, heating a metal heat exchanger where the heat is then transferred to the air. Air is pushed through the heat exchanger by the air handler’s furnace fan and then forced through the home’s ductwork downstream of the heat exchanger.
While furnaces carry heat in warm air, boiler systems distribute the heat in hot water, which it produces as it passes through radiators or similar devices throughout the house. The cooled water then returns to the boiler to be reheated. You may often hear water systems referred to as hydronic systems. Generally, residential boilers use natural gas or heating oil for fuel.
There are steam boilers, which are less common today. In steam boilers, water is boiled and steam carries heat through the house, condensing to water in the radiators as it cools. Oil and natural gas are commonly used. Boilers use a pump to circulate hot water through pipes to radiators, producing heat.
The word heat in heat pump is a bit misleading because this residential HVAC unit also doubles as an A/C system. An air conditioner works by moving heat from the cooler indoors to the warmer outside. In winter, the heat pump reverses this trick, taking up heat from the cold outdoors with the help of an electrical system, and releasing that heat inside the house. Almost all heat pumps use forced warm-air delivery systems to move heated air throughout the house.
Gas-Fired Space Heaters
A gas-fired space heater can include wall-mounted, free-standing, and floor furnaces. These work great in rooms that lack ductwork or only need seasonal.
Radiant Floor Heating
Radiant floor heating is cutting-edge technology in heating systems. It’s a residential HVAC unit that circulates warm water in tubing under the floor. The circulating warm water warms the floor, which then warms the people using the room. Other benefits of radiant flooring are that it is very efficient and highly controllable. However, it is very expensive and requires an experienced system designer to install. It will also limit your flooring choices. You can’t bury your heat source under shag carpeting.
Geothermal Heating and Cooling
Geothermal heat pumps use the Earth’s steady ground and water temperature as a heat source in the winter and as a heat storage source in the summer. The ground loop components of a geothermal heating and cooling system can last up to 50 years!
A geothermal heat pump system burns no fossil fuel to produce heat, and it generates far fewer greenhouse gas emissions than a conventional furnace. It also completely eliminates a potential source of poisonous carbon monoxide within the home.
Traditional gas or electric forced-air systems usually top out at 90 percent efficiency. But, a geothermal system is 100 percent efficient. That efficiency translates into hundreds of dollars saved.