YOU ARE HERE: LAT HomeCollections QUESTION: My old central air conditioner still works, but I wonder if I should replace it with a super-efficient one. How much can I expect to save on my electric bills? Are the new natural gas cooling units efficient?ANSWER: Your old air conditioner probably has a SEER (efficiency ratio) of about 6 or 7. A new super-efficient electric unit has a SEER of 15. Installing one can cut your cooling costs by more than 50%. New natural gas central air conditioning units have an equivalent SEER as high as 27.New super-efficient electric air conditioning units use two-speed compressors and variable-speed indoor blowers. On the low energy saving speed (runs at high speed only on the hottest days), each cycle run time is longer. Indoor temperature swings between on-off cycles are virtually eliminated.The air gently circulates almost continuously and noise is reduced. With soft start, the initial burst of warm (cold in the winter) air from the ducts is eliminated.

This is ideal for allergy sufferers because air cleaners are more effective and humidity levels, mold, mites, etc. are reduced.The indoor blowers use special electrically commutated motors. These not only provide true variable-speed operation for better comfort, but they use less than half as much electricity as standard blower motors.The most efficient single-speed air conditioning units use scroll compressors. Scroll compressors have fewer moving parts than standard reciprocating piston compressors. Without pistons and valves, scroll compressors are quieter too.As scroll compressors wear over years of operation, they seal better and operate smoother than when they were new. Their basic design is reliable, and they should continue to operate at high efficiency levels for many years.If you have natural gas, there are gas-powered air conditioning units that use a no-compressor absorption process. These also heat your house in the winter.Another super-efficient gas central air conditioning and heating unit uses a compressor.

With an equivalent SEER of 27, it can cut cooling costs by 75%. air conditioning unit filter changeIt looks just like a standard electric central air conditioning unit outdoors and is quieter.best ac units consumer reportsA small natural gas-powered engine runs the compressor. clicking in ac unitSince an engine can run at any speed, its microprocessor continually, fine-tunes the cooling output (17 levels) to the precise cooling needs of your house.In the winter, this year-round gas air conditioning unit heats your house at more than 100% efficiency. It combines the heat pump principal with the excess heat from running the engine. This can cut your heating costs by half too.Write for Update Bulletin No. 528 showing a buyer's guide of super-efficient gas and electric central air-conditioning manufacturers listing efficiency, cooling capacity, compressor type and number of speeds, features and a savings-selector chart.

Please send $2 and a business-size self addressed, stamped envelope to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.What Sun Room Design Is Most Efficient?Q: I am planning the addition of a sun room to my house. I will use it for growing some plants and hope to get some free solar heating in the winter from it. Should I get one with a slanted or vertical front?A: Get one with a vertical or near vertical front. Although the slanted front designs are usually less expensive, they tend to overheat in the summer, even in northern climates.If you plan to use your sun space to help heat your house in the winter, include adequate solar mass. This is often accomplished with a heavy brick or concrete floor. You will also need a fan to move the warm air indoors.Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244. Seizure Led to FloJo's DeathHis 104 scores make his caseRestaurant review: South Beverly GrillBrutal Murder by Teen-Age Girls Adds to Britons' ShockComaneci Confirms Suicide Attempt, Magazine Says

Natural gas is one of the most affordable forms of energy available to the residential consumer. In fact, natural gas has historically been a better value than electricity as a source of energy in the home. The Department of Energy (DOE) estimates that in 2011, natural gas is the lowest cost conventional energy source available for residential use. According to the DOE, natural gas costs approximately 68 percent less than the cost of electricity, per Btu (British thermal unit). Not only is natural gas a good value for the residential consumer, it also has a number of varied uses. The best known uses for natural gas around the home are natural gas heating and cooking. Cooking with a natural gas range or oven can provide many benefits, including easy temperature control, self ignition and self cleaning, as well as being approximately one-half the cost of cooking with an electric range. Many of the top chefs prefer natural gas ranges for their quick heating ability and temperature control.

Newer generations of natural gas ranges allow for some of the most efficient, economical, and responsive cooking appliances in existence. Installing Residential Natural Gas Distribution Source: Duke Energy Gas Transmission Canada Natural gas is one of the most popular fuels for residential heating. According to the American Gas Association, 62 million homes in the U.S are heated using natural gas. As of 2009 this number represented about 56 percent of households in the United States.  Approximately 23 percent of the total natural gas consumed nationwide is used for residential purposes.  This popularity is also shown through the high proportion of new homes built with natural gas heating. Census Bureau in its report Annual 2010 Characteristics of New Housing report, 54 percent of new family homes completed in 2010 used natural gas for heating, followed by 43 percent that use electricity for heating, 1 percent that use oil and 2 percent that use other forms.  These numbers may be biased by the recent recession, which spurred the number of new homes built in each of the previous 15 years to exceed 1 million homes per year, compared to 2008 and 2009 when the combined number of new homes built was just over 1 million. 

Construction of new homes in the South and in areas lacking pipeline infrastructure may also explain the decrease in homes built with natural gas heating systems.  A more historical perspective shows the percentage of new homes built with natural gas for space heating to be between 60 and 70 percent. To learn more about trends in natural gas use, click here to view the Energy Information Administration’s (EIA’s) report, Natural Gas Markets: Recent Trends and Prospects for the Future, which outlines significant historical trends and their implications for the future of natural gas use. Despite this massive increase in the proportion of homes using natural gas, the actual volume of natural gas consumed has not increased to the same degree, due to increased efficiency of natural gas appliances. Modern top of the line gas furnaces can achieve efficiencies of over 90 percent (meaning that only 10 percent of the energy contained in the natural gas is lost as waste heat). Even low-end natural gas furnaces achieve high efficiencies, around 78 percent.

In addition to heating homes, natural gas can also be used to help cool houses through natural gas powered air conditioning. Natural gas air conditioning is nothing new, in fact, it provided most of the air conditioning requirements of the 1940s and ‘50s.  Due to new advancements in technology and efficiency, natural gas air conditioning is experiencing a resurgence in popularity. Although natural gas air conditioner units are initially more expensive than a comparable electric unit, they are considerably more efficient and require less maintenance. Modern residential air conditioner units use close to 30 percent less energy than in years past, and have an expected working life of 20 years with very little maintenance. Natural gas appliances are also rising in popularity due to their efficiency and cost effectiveness. Although many natural gas-powered appliances are initially more expensive than their electric counterparts, they are commonly much cheaper to operate, have a longer expected life, and require relatively low maintenance.

Other natural gas appliances include space heaters, clothes dryers, pool and jacuzzi heaters, fireplaces, barbecues, garage heaters and outdoor lights. All of these appliances offer a safe, efficient, and economical alternative to electricity or other fuel sources. The same natural gas pipes that supply gas to a furnace can be used to supply energy for all of the appliances listed above, making installation simple and easy. Although natural gas has many uses and can supply energy to a vast number of residential appliances, there are some energy requirements around the house which cannot be satisfied by natural gas. A television, blender or microwave, for instance, will likely never be powered directly by natural gas, but will instead require electricity. However, natural gas can still power these appliances in the home, by what is known as ‘distributed generation’. Distributed generation refers to using natural gas to generate electricity right at the doorstep. Natural gas fuel cells and microturbines both offer the residential consumer the capacity to disconnect from their local electric distributor, and generate just enough electricity to meet their needs.

Although this technology is still in its infancy, it is very promising in being able to offer independent, reliable, efficient, environmentally-friendly electricity for residential needs. The very first natural gas fuel cell was installed in a house in Latham, New York in July 1998. The system was plugged into the home’s natural gas line as the fuel supply, and is now completely independent of any outside electricity. Because a significant amount of electricity is wasted when it is distributed through power lines from a central power plant to the home, on-site electric generation could lead to significantly higher energy efficiency, which translates to cost savings for the residential consumer. For more information on fuel cells, click here. For more information on natural gas and the generation of electricity, click here. Natural gas is also an environmentally-friendly fuel, and is a good option for the environmentally-conscious homeowner. To learn more about the environmental benefits of natural gas, click here.