Air-Conditioning Systems Clovis NM
Clovis , NM
Monday 8:00 AM - 5:00 PM
Tuesday 8:00 AM - 5:00 PM
Wednesday 8:00 AM - 5:00 PM
Thursday 8:00 AM - 5:00 PM
Friday 8:00 AM - 5:00 PM
AC Unit Installation, Boiler Installation, Central AC Installation, Commercial HVAC Service, Furnace Installation, Heat Installation, Heat Pump Installation, HVAC Contractors, HVAC Maintenance, Outdoor Cooling System Installation, Residential HVAC Service, Ventilation System Service
Service Types and Repair
AC Unit, Boiler, Central AC, Furnace, Heat Pump, Heater, Outdoor Cooling System
Monday 12:00 AM - 12:00 AM
Tuesday 12:00 AM - 12:00 AM
Wednesday 12:00 AM - 12:00 AM
Thursday 12:00 AM - 12:00 AM
Friday 12:00 AM - 12:00 AM
Saturday 12:00 AM - 12:00 AM
Sunday 12:00 AM - 12:00 AM
Las Cruces, NM
Portales , NM
Monday 24 Hours
Tuesday 24 Hours
Wednesday 24 Hours
Thursday 24 Hours
Friday 24 Hours
Saturday 24 Hours
Sunday 24 Hours
AC Unit Installation, Central AC Installation, Commercial HVAC Service, Duct Cleaning, HVAC Cleaning, HVAC Contractors, Residential HVAC Service
Service Types and Repair
AC Unit, Central AC
Las Cruces, NM
In the United States, most residential central air-conditioning systems are split. In a split system, the outdoor components - a compressor, condenser coil and fan packaged in a weatherproof enclosure - are installed on a concrete pad. The indoor components in systems where they are combined with a central air-heating system include the evaporator coil and expansion device and use that system's ducts. The coil is placed at the discharge side of the furnace. It is often called an A-coil, because of its letter-like shape. If the home does not have an air-heating system, then the indoor equipment is housed in an air handler placed in the ducts. The air handler contains the fan and the evaporator and sometimes a heat coil. The all-important refrigerant circulates within the sealed loop between the outdoor and indoor components and is the medium that carries the heat from indoor to outdoor. Indoors, the refrigerant in the evaporator coil is cooler than the room air and, therefore, takes on heat; outdoors, the refrigerant in the condenser coil is hotter than the street temperature and gives off heat. The refrigerant circulates between the indoor and outdoor coils in a sealed piping loop. As the refrigerant (which has a boiling point low enough to evaporate at a relatively low temperature) circles the loop, the temperature and pressure of the refrigerant vary, and it changes from a gas to a liquid and back to a gas. Hitching a Ride: How Central Air Conditioning Works To get an insider's view of the refrigerant's cycle, let's travel along with the refrigerant as it navigates the piping loop. We'll join the refrigerant as it leaves the indoor evaporator coil. At that point, it is a warm gas at low pressure that has taken heat from the house.
The outdoor compressor is drawing the refrigerant to it. (The piping that travels from inside the house to the compressor is called the suction line.) Under the increased pressure applied to the gas by the compressor, the refrigerant heats up. The pressurized hot gas is then pumped through the outdoor condensing coil. The gas in the condenser is hotter than the outside air, so when the fan blows air over the outdoor coil, the vapor inside the coil cools down and condenses into a liquid. The condenser is so named because it condenses the hot refrigerant. In passing through the condensing coil, the refrigerant changes from a warm gas to a hot liquid, which releases heat to the outdoors. The still relatively warm, pressurized liquid refrigerant flows back into the house (through the smaller liquid line) where it passes through an expansion device, which can be a small section of pipe with a considerably reduced diameter, located just before the evaporator. As the refrigerant passes the restriction, it expands, and the pressure and temperature drop. Decreasing pressure causes the refrigerant to turn cold. The liquid refrigerant evaporates, absorbing the heat passing over the coil and exiting the coil as a warm gas. At this point, the cycle begins again. EFFICIENT TECHNOLOGIES Compressor Designs There are two common compressor designs used in residential central air-conditioning systems: reciprocating compressors, which use a reciprocating piston in a cylinder similar in design to a car cylinder and are very reliable; and scroll compressors, a newer type that has fewer parts and features two orbital planes that come into contact with one another during operation. The planes vary the volume of the refrigerant, creating high- and low-pressure sides. Already more popular than the older design in new residential systems, they have the potential to be more efficient. Demystifying Dehumidification Older central air-conditioning systems and many new builder-grade or price-sensitive air-conditioning systems are sized to cool homes on the hottest days, but they do not have the flexibility to run at lower compressor capacities for less severe needs. Some newer systems, however, place a greater emphasis on daily comfort and include use of two-speed compressors, such as the Lennox HSX19 and the Carrier 38TDB systems, or two independent compressors and variable-speed fans, such as the Trane XL19i, to regulate not only temperature but also humidity, to achieve the best combination of temperature and humidity.
The Trane XL19i air-conditioning system, featuring a SEER (seasonal energy efficiency ratio) rating of up to 19.50, uses dual Climatuff compressors of different capacities for two-stage cooling, each optimized for the potential load it will operate and, when matched with a Trane variable-speed indoor unit, independent humidity control. The system, which runs one compressor at a time and can remove up to 24 gallons of moisture a day, delivers a true 50 percent capacity on first-stage cooling and 100 percent capacity on second stage. The outdoor condenser incorporates Spine Fin woven coils that provide more edge surface than traditional design coils, for maximized heat transfer, notes Greg Walters, Trane Outdoor Systems manager. When aiming for comfort, dehumidification is as important as cooling. Here's how air conditioners dehumidify air: The temperature at the surface of the evaporator coil, which is made up of finned tubes, is below the dew-point temperature of the air. (The dew-point temperature is the temperature of the air at 100 percent relative humidity.) When warm air is blown over the coil, the moisture in the air condenses onto the surface of the coil and drips down to a pan. A hose typically removes the water to a drain. (Despite the terminology, moisture is condensed at the evaporator and not at the condenser. The coils are named for what occurs within the tubes.)
In air-conditioning systems that allow for control of temperature and humidity separately, controls can be user-set for any combination of high or low humidity, and high and low temperatures, saving energy while maximizing comfort for a range of ambient weather conditions. For example, the Trane XL19i offers users that type of economical comfort control. For greater humidity control, when either compressor is running, the fan can operate at 50 percent, 80 percent or 100 percent of full speed for various periods of time (called Comfort-R), providing up to six different combinations of fan and compressor settings, for maximum comfort under all temperature and humidity conditions. Additionally, the homeowner can set the controls to regulate how the unit handles latent and sensible heat removal. For example, you could have the humidistat run the fan speed at 80 percent when there is high humidity but not overly hot temperatures, and have it run at 100 percent when the humidity is low but the temperature is creeping up. Label Language There are a few labels attached to new air-conditioning systems that are worth examining, to make sure the system you buy is right for your needs and intentions. When selecting a home air-conditioning system, check out the numbers on a few key labels. Look closely at the SEER rating, which is government mandated. The higher the ratio, the lower the cost of operation (and the kinder the system to the environment). The minimum SEER is currently 10, but effective Jan. 1, 2006, the minimum rating for new systems will be set at 12; some high-sector systems now have a rating of 19 or even higher. "Systems with higher SEER ratings do absolutely as good a job in cooling a home as a system with a lower rating. The difference is the energy bills are smaller," says Michael Hughes, an air-conditioning engineer consultant to manufacturers and a member of ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers). "How long it takes to cool down a house is a function of the size of the equipment, not the energy efficiency." 10 SEER represents approximately 80 percent of today's market. (Homes built on spec are almost always outfitted with 10-SEER air-conditioning systems.) You may also want to consider the label indicating the type of refrigerant in the system. The old standard, R-22, is an HCFC (hydrochlorofluorocarbon) that contains ozone-depleting chlorine. It is being phased out of the manufacturing process and replaced by the equally effective R-410A, which has no chlorine. By 2010, R-22 will be disallowed in new units.
In fact, Hughes notes, "There is evidence that R-410A might even be a little more efficient on the same cost basis. A consumer might want to factor the type of refrigerant into any assessment, because the life expectancy of the equipment is around 20 years, and at some point, R-22 may become scarce and, therefore, more expensive." Another label to look for is Energy Star. Energy Star products conform to U.S. government standards for energy efficiency aimed to reduce both pollution and energy consumption. The Energy Star logo indicates that a unit is at least 20 percent more efficient than products that meet minimum federal government standards. Banning Heat and Humidity There are two kinds of heat an air conditioner removes - temperature-associated, called sensible heat, and moisture-associated, called latent heat. When an air-conditioner compressor is running, it is always removing heat and humidity. However, a thermostat only measures sensible heat. It controls temperature but not humidity. If you were controlling only temperature in your home, then you would need to run the air-conditioning unit at a lower setting than you would have to if you also wanted to control humidity. However, if you increase the rate of dehumidification, then you can set the thermostat a couple, or even a few, degrees warmer and still feel comfortable. When a compressor runs, it removes latent and sensible heat. By running the compressor and the evaporator fan at a lower speed for a longer period of time, you can remove more humidity because the air spends a longer time passing the coil.
Also, it costs less to run an air conditioner continuously for longer periods at lower speeds than it does to run the same unit at a higher speed that cycles on and off. Humidity removal is controlled by the speed of the airflow past the indoor evaporator coil. High-sector systems that have either two-speed compressors or two compressors, use a variable-speed fan motor at the evaporator coil to optimize humidity removal for each compressor setting. The term "variable speed" refers to the ability to select fan speed. Some manufacturers, such as Lennox, for example, offer two-speed systems that feature two levels of operation: low for mild days and high to accommodate the heat of summer at its peak. Because the noise level of an operating unit is most likely quieter at a lower setting, a two-speed system may well offer the advantage of quieter operation during times that the higher speed is not needed. By regulating both fan speed and compressor speed, you are essentially regulating the cfm (cubic feet per minute) of humid air passed over the evaporator coil, Walters notes. "With some systems, it is possible to further regulate fan speeds within the high and low settings to fine tune the amount of moisture the system removes from the indoor air." When the fan runs at low speed, the compressor runs at low speed as well, so that the cfm matches BTUs. Otherwise, the evaporator coil would get too cold and freeze up. The Lennox HSX19 central air conditioner, carrying a 19.20 SEER rating, features variable-speed motors and a two-stage scroll compressor that uses the chlorine-free R-410A refrigerant. The unit runs at low stage (about 80 percent of what the motor can deliver) up to 80 percent of the time, staying at that setting as long as that speed satisfies the conditions. Plus, because the variable-speed motors bring on the equipment slowly - rather than in a rush - the homeowner has consistent airflow throughout the home, says Tom Overs of Lennox Industries. And because cooling is based on need, it is energy efficient.
"The system can be far less expensive to operate than a standard air conditioner that always runs at full stage." The unit is also designed for quiet operation, Overs notes. It features a precision-balanced, direct-drive fan, passive sound-dampening fan grill, and an insulated compressor cabinet with vibration isolators. The Lennox unit's home comfort controller, SignatureStat, combines the functions of a thermostat and a humidistat, and controls temperature and humidity independently. If there is a need to remove humidity (or add humidity during the heating season), the controller brings on the HVAC (heating, ventilation and air conditioning) system without necessarily calling for cooling or heating. The unit, at maximum need, can remove up to 75 gallons of water vapor daily. Other manufacturers offer a one-compressor system that runs at two speeds. The Carrier 38TDB WeatherMaker two-speed Puron system, for example, has a single two-stage compressor that operates at low speed for normal cooling requirements and high speed for more demanding conditions. The WeatherMaker's control board monitors operation and automatically adjusts the system to deliver the optimal combination of comfort and energy savings. The compressor operates at low speed up to 75 to 80 percent of the time to maintain consistent temperatures throughout the home, points out Jon Shaw, manager of corporate communications at Carrier Corp. "The longer operating cycles create a more continuous flow of cool, conditioned air, along with greater humidity control." When additional cooling is required, the system, which achieves up to 18 SEER, automatically switches to high-speed operation. When combined with a Thermidistat control and a variable-speed furnace or fan coil, the unit can remove up to 25 gallons of water a day. The two-speed compressor was designed specifically for use with Puron refrigerant, which provides higher-efficiency heat transfer than R-22 refrigerant, while meeting the 2010 environmental guidelines, according to the company. Leaky Ducts Sink Efficiency Air-conditioning systems often waste energy through duct leakage.
Some studies show that up to 20 percent of energy costs for an air-conditioning system can dissipate through leaks. Therefore, it is important for installers to test for leakage. When the ducts carrying cooled air leak, they waste the already conditioned air and, even worse, may pull in unconditioned air from outside or from unconditioned spaces because of the negative pressure created in the house. Duct tape, despite its name and myriad other uses, is not suitable for sealing ducts - it breaks down too quickly. The best and longest-term solution is to fasten the duct sections together mechanically (i.e., with screws), then seal the duct with mastic and fiberglass tape. The mastic is a caulking material, and the fiberglass tape provides rigid support when coupled with the mastic. A good sealing job can reduce duct leakage to less than 3 to 5 percent of fan flow. To optimize your ducts' efficiency, they should also be well insulated. Designed for buildings without ductwork or with inadequate ductwork, the split Unico System is a high-velocity mini-duct heating and cooling system that, according to Tom Taylor, marketing director, is well suited to historic homes or architecturally unique homes where a homeowner might not want to disturb the structure aesthetically. The system features modular air handlers, coils and flexible 2-inch supply tubing that can be routed through ceilings, floors, closets and wall cavities, eliminating the need for demolition or construction. (The indoor air-handling components and ductwork are matched to third-party outdoor components.)
Unlike conventional air-conditioning systems that blow air over the evaporator coil, the Unico System draws the air, or aspirates it, over a coil that has a large amount of surface area, enabling efficient cooling of the air that passes over. Air in the system is passed at low airflow over evaporator coils at a colder temperature than conventional systems, according to the company, and then passes at high speed through the ducts. The high-velocity system, which runs at up to 200 cfm per ton, removes 30 percent more moisture than traditional systems, Taylor says. Any draft of cooled air dissipates into the general airstream about two feet from the outtakes, which are generally tucked into perimeters and corners of rooms, out of the flow of traffic. "This method of air distribution has the added benefit of providing even temperatures from ceiling to floor - with less than a 2° F variance and no hot or cold spots." Another ductless technology is available from Mitsubishi Electric. The Japanese giant has an HVAC Advanced Products Division, which manufactures the Mr. Slim split-ductless air conditioners. These systems are composed of an outdoor unit and up to three indoor units. Similar to the Unico product in that they are both clever solutions for older home retrofits, the Mr. Slim products require only one 3-inch hole in the wall for each interior unit. The interior units are mounted up high on the wall (freeing up window space) and up to three of them can be zoned for spot-cooling solutions around the home. The compressor in the outdoor unit pumps coolant to the air handler through refrigerant lines that go through the 3-inch wall opening. The inverted compressor technology modulates the speed of the compressor to deliver the exact amount of cooling (or heating) required by each zone, which reduces temperature fluctuations. The company claims that this system requires less energy to operate and maintain comfortable temperatures than conventional systems, which start and stop continuously. They rate their middle-of-the-road product (the MSZ 12UN) at 12,000 BTUs per hour with a 13-SEER rating. So you see, if you know your house and its characteristics, and you understand the basics of air-conditioning technology, you should be able to find the right system for you. There is virtually no good reason to sweat out the summer months. William and Patti Feldman are a husband-and-wife freelance team based in New York.