All modern air conditioning systems, even small window package units, are equipped with internal air filters. These are generally of a lightweight gauzy material, and must be replaced or washed as conditions warrant. For example, a building in a high dust environment, or a home with furry pets, will need to have the filters changed more often than buildings without these dirt loads. Failure to replace these filters as needed will contribute to a lower heat exchange rate, resulting in wasted energy, shortened equipment life, and higher energy bills; low air flow can result in iced-over evaporator coils, which can completely stop air flow. Additionally, very dirty or plugged filters can cause overheating during a heating cycle, and can result in damage to the system or even fire.
If you believe that the ac not working or you’re getting little or no cold air, check these three things first. Make sure all the registers in the house are wide open. Then be sure the furnace filter is clean. Then go outside and clean off the condenser coils (Photo 2). If several registers were closed or the filter was clogged, the reduced airflow could have caused the evaporator coil to ice up and stop cooling your home. If you’ve changed the filter and opened all the registers and you’re still not getting airflow at the registers, deice the A-coil. Move the thermostat mode switch from “Cooling” to “Off” and move the fan switch from “Auto” to “On.” Let the blower run for at least 30 minutes or until there’s good airflow at the registers. Then turn the AC back on to test it. If it works for the next 12 hours, you’ve solved the problem.
We relocate frequently and one of the biggest hassles of relocating to new areas is finding reputable companies that send qualified technicians to perform work when you need it, whether for annual preventative maintenance or during a house emergency. We’ve been through the process several times and always dread researching and trying new companies. This was our first HVAC call here in northern Virginia. We are in new construction and chose not to use the builder’s sub-contractor for a technician call but looked through Carrier’s website for a local business. Jeremy Garner with HVAC Unlimited responded to our service request the morning following our call. I shadowed him performing work and he was patient while I peppered him with questions. He helped expand my HVAC knowledge in order to be a better property owner of our systems. He performed the work we thought was necessary, in a timely and professional manner, and gave us options for future annual maintenance. HVAC Unlimited is definitely on our list of go-to contractors.
In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object. Franklin and Hadley confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to speed up the evaporation. They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm (1⁄4 in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment one may see the possibility of freezing a man to death on a warm summer's day."[9]
The Environmental Protection Agency (EPA) requires that all technicians who open a system containing a controlled refrigerant be certified to do so. There are four levels of certification, one of which is a “universal” certification to allow the HVAC technician to work on any type of equipment containing refrigerant. Your HVAC technician should be certified as “Level II Certified” at a minimum or, preferably, “Universal Certification” to work on your central air conditioner. Obtaining this certification information from your professional HVAC technician may be required in the event you are working with a realtor to sell your home. Costs for certification average $40 to $240.
Natural ventilation is a key factor in reducing the spread of airborne illnesses such as tuberculosis, the common cold, influenza and meningitis. Opening doors, windows, and using ceiling fans are all ways to maximize natural ventilation and reduce the risk of airborne contagion. Natural ventilation requires little maintenance and is inexpensive.[19]
The performance of vapor compression refrigeration cycles[27] is limited by thermodynamics. These air conditioning and heat pump devices move heat rather than convert it from one form to another, so thermal efficiencies do not appropriately describe the performance of these devices. The Coefficient-of-Performance (COP) measures performance, but this dimensionless measure has not been adopted. Instead, the Energy Efficiency Ratio (EER) has traditionally been used to characterize the performance of many HVAC systems. EER is the Energy Efficiency Ratio based on a 35 °C (95 °F) outdoor temperature. To more accurately describe the performance of air conditioning equipment over a typical cooling season a modified version of the EER, the Seasonal Energy Efficiency Ratio (SEER), or in Europe the ESEER, is used. SEER ratings are based on seasonal temperature averages instead of a constant 35 °C (95 °F) outdoor temperature. The current industry minimum SEER rating is 14 SEER.[28]
Whether in your home or business, we can get your air conditioner working again in no time! Randazzo Heating, Cooling, and Fireplaces has a staff of experienced technicians who will come to your rescue! We can also keep you updated on when your air conditioner should have routine maintenance inspections, so you can keep it performing at optimum efficiency.
AC air handler squealing or grinding noises. Though most air handlers have direct-drive motors, some older units may be belt-driven. Squealing sounds from a belt-drive air handler generally occur when the belt that connects the motor to the blower slips. In most cases, the belt is improperly aligned or worn and needs replacement. Follow the instructions above under Air Conditioner Not Blowing Air and refer to your owner’s manual.
The selection of indoor units has one restriction: their total power should not exceed the capacity of the outdoor unit. In practice, however, it is very common to see a multi-split system with a total capacity of indoor units greater than the outdoor capacity by at least 20%. However, it is wrong to expect better performance when all indoor units are turned on at the same time, since the total capacity of the whole system is limited by the capacity of the outdoor unit. Simply put, the outdoor unit will distribute all its power to all operating indoor units in such a way that some of the rooms may not have a very comfortable temperature level. However, the calculation of the total power is not simple, since it takes into account not only the nominal power of the units, but also the cooling capacity, heating, dehumidification, humidification, venting, etc.

Even with the best air conditioning repair service Phoenix can offer, an AC unit that has reached the end of its shelf life must be replaced. If you are ready to upgrade or replace that aging system, call us now for a free estimate, or check out our AC Unit Replacement section. In addition to offering our own Precision Line with the best warranty available in the industry, we also partner with industry leaders to offer the highest quality equipment at the best possible price, and we personally stand behind all of our new equipment installations.
When natural gas, propane or heating oil are burned in a furnace, the resulting hot combustion gasses by burning natural gas, propane or heating oil circulate through a heat exchanger. The heat exchanger will, in turn, release that heat to be circulated by the furnace’s blower. The flue gas then travels through the flue vent, which carries the gas outside of the home. When a heat exchanger is cracked, it generally will require a complete system replacement. That is one of the reasons why we highly recommend annual preventive maintenance on your home’s furnace – this preventative furnace inspection and maintenance can greatly prolong the life of your home heating system.
If your compressor doesn’t have an overload button and you hear it humming or buzzing, poke a screwdriver or stick down through the top grille and try to spin the fan blades clockwise. If doing this gives the fan enough of a boost to get it going, the unit has a faulty capacitor that must be replaced. See How to Test and Replace an AC Run Capacitor, above.
In a thermodynamically closed system, any power dissipated into the system that is being maintained at a set temperature (which is a standard mode of operation for modern air conditioners) requires that the rate of energy removal by the air conditioner increase. This increase has the effect that, for each unit of energy input into the system (say to power a light bulb in the closed system), the air conditioner removes that energy.[30] To do so, the air conditioner must increase its power consumption by the inverse of its "efficiency" (coefficient of performance) times the amount of power dissipated into the system. As an example, assume that inside the closed system a 100 W heating element is activated, and the air conditioner has a coefficient of performance of 200%. The air conditioner's power consumption will increase by 50 W to compensate for this, thus making the 100 W heating element cost a total of 150 W of power.
Air conditioner inverter Air door Air filter Air handler Air ionizer Air-mixing plenum Air purifier Air source heat pumps Automatic balancing valve Back boiler Barrier pipe Blast damper Boiler Centrifugal fan Ceramic heater Chiller Condensate pump Condenser Condensing boiler Convection heater Cooling tower Damper Dehumidifier Duct Economizer Electrostatic precipitator Evaporative cooler Evaporator Exhaust hood Expansion tank Fan coil unit Fan heater Fire damper Fireplace Fireplace insert Freeze stat Flue Freon Fume hood Furnace Furnace room Gas compressor Gas heater Gasoline heater Geothermal heat pump Grease duct Grille Ground-coupled heat exchanger Heat exchanger Heat pipe Heat pump Heating film Heating system High efficiency glandless circulating pump High-efficiency particulate air (HEPA) High pressure cut off switch Humidifier Infrared heater Inverter compressor Kerosene heater Louver Mechanical fan Mechanical room Oil heater Packaged terminal air conditioner Plenum space Pressurisation ductwork Process duct work Radiator Radiator reflector Recuperator Refrigerant Register Reversing valve Run-around coil Scroll compressor Solar chimney Solar-assisted heat pump Space heater Smoke exhaust ductwork Thermal expansion valve Thermal wheel Thermosiphon Thermostatic radiator valve Trickle vent Trombe wall Turning vanes Ultra-low particulate air (ULPA) Whole-house fan Windcatcher Wood-burning stove
Whether you have an electric or gas furnace, you shouldn’t have to suffer when your heater is not working. At Sears Home Services, our technicians fix many of the top furnace manufacturers. The issues you may face with your furnace can vary depending on the type of heating system. If you own an electric model and it isn’t working, some of the potential causes include:

All modern air conditioning systems, even small window package units, are equipped with internal air filters. These are generally of a lightweight gauzy material, and must be replaced or washed as conditions warrant. For example, a building in a high dust environment, or a home with furry pets, will need to have the filters changed more often than buildings without these dirt loads. Failure to replace these filters as needed will contribute to a lower heat exchange rate, resulting in wasted energy, shortened equipment life, and higher energy bills; low air flow can result in iced-over evaporator coils, which can completely stop air flow. Additionally, very dirty or plugged filters can cause overheating during a heating cycle, and can result in damage to the system or even fire.
Before selecting the installation location of air conditioner, several main factors need to be considered. First of all, the direction of air flow from the indoor units should not fall on the place of rest or work area. Secondly, there should not be any obstacles on the way of the airflow that might prevent it from covering the space of the premises as much as possible. The outdoor unit must also be located in an open space, otherwise the heat from the house will not be effectively discharged outside and the productivity of the entire system will drop sharply. It is highly advisable to install the air conditioner units in easily accessible places, for further maintenance during operation.

Though Harrison had commercial success establishing a second ice company back in Sydney in 1860, he later entered the debate over how to compete against the American advantage of ice-refrigerated beef sales to the United Kingdom. He wrote: "Fresh meat frozen and packed as if for a voyage, so that the refrigerating process may be continued for any required period", and in 1873 prepared the sailing ship Norfolk for an experimental beef shipment to the United Kingdom. His choice of a cold room system instead of installing a refrigeration system upon the ship itself proved disastrous when the ice was consumed faster than expected.[citation needed]

In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object. Franklin and Hadley confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to speed up the evaporation. They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm (1⁄4 in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment one may see the possibility of freezing a man to death on a warm summer's day."[9]
×