Frequently Asked Questions

1. Q. What is air conditioning?

A. Air conditioning is the control of air movement, filtration, humidity, and temperature of an atmospheric environment. It is normally associated with the cooling and dehumidification process of air and thereby identified with refrigeration.

2. Q. What is relative humidity?

A. Air we breathe contains moisture or water vapor, and the amount of moisture at a certain temperature which the air can hold is fixed to the saturation point of 100%. We can see a cloud which is at it's temperature is saturated 100% relative humidity. In the evenings as temperatures decrease, moisture precipitates out and falls to the grass, we call it dew. Figuratively during the night the saturated air can not hold the moisture and thus the moisture falls to the grass. A general theorem is that the warmer the air the more moisture the air can hold, and the cooler the air the less moisture can be retained. In the event of an air conditioning, the air passes across the much cooler evaporator coil and the air is cooled, and at the same time moisture can no longer be supported by the air and thus condenses or dew point occurs and water vapors turn to water and are expelled from the air and form condensate which is drained from the system.

3. Q. What is meant by a "ton" of refrigeration?

A. The term ton is of course 2000 pounds which primarily has nothing to do with refrigeration, but ice was the only means of refrigeration for many years and was harvested from frozen lakes and was stored for food preservation. By definition, a ton of refrigeration is 12,000 BTU (British thermal units). This is found by taking the heat of fusion of water, which is 144 BTU per pound of water and melting the ice, still at 32 degrees Fahrenheit for 24 hours: 144 x 24 = 288,000 BTU. Then to divide 288,000 BTU by 24 hours resulting in 12,000 BTU. That 12,000 BTU per hour is a ton of refrigeration, and is the basis of air conditioning calculations.

4. Q. What is direct expansion equipment?

A. Direct expansion, DX, or primary exchange is a system where there are two heat exchanging devices. The compressor section is the pump which boosts the pressure and drives the heat to the outside or condenser where the temperature difference cools the refrigerant and it condenses back to a high pressure liquid. The refrigerant liquid then passes to the expansion valve or other metering device where it passes through the restriction to the evaporator section where it is vaporized and absorbs heat from the fluid or air which is passing across the evaporator coil. The vapor then returns to the compressor to continue the cycle. Direct expansion as opposed to secondary exchange or chillers is much more simple. The secondary exchange has a double exchange system where the primary exchanger is as described and then the chilled fluid is then pumped to another exchange system which distributes the final desired results. Among the secondary exchange systems is the cascade system which may be two or three refrigeration systems which are linked together to achieve ultra low temperatures.

5. Q. What about heating?

A. There are several modes for heating, almost all are either directly or indirectly linked to fossil fuels. Oil heat has the most BTU available per unit, and gas or LP gas will have the next highest BTU available. Electric heat is fixed by definition in the watt, but most electric is created with fossil fuel to drive the generators at the power plants. Solar heat, geothermal heat, and the like are only accessible in certain areas due to the nature. Wind can produce electric for heat, but again very limited locations. Our primary source for heating in SW Florida is electric either heat pumps of straight electric heat elements. Heat load calculations are figured by degree days and or design temperatures. The Fort Myers area the design temperature is 42 degrees Fahrenheit with the indoor temperature to be set at 68 F. If the temperature falls below 42 F outdoors, the indoor temperature may also fall below the setpoint of 68 F. Most systems are installed with more heat elements for backup reserve therefore allowing the comfort to still remain at the desired temperature. One watt is 3.14 BTU. Most heaters are in KW which is 1000 watts so if you had 10 KW of heat the amount of heat would be 31,400 BTU or 2.5 tons of heat.

6. Q. Can I have plants on or around the air conditioner?

A. In most cases plants on the air conditioner is a no-no, but plants around the air conditioner is all right as long as a distance for serviceability access is maintained. Normally for most sides of the air conditioner 18 inches is acceptable, and at the control access 24 to 36 inches is preferred. When service is required, plants sometimes may be in the way due to the nature of the service performed. Most technicians are very careful during their work, but when there is not enough room to work it generally takes more time and thus a larger repair bill.

7. Q. Do I have to change the Filters? How often does this need to be done?

A. Filters should be regularly inspected and cleaned or changed. Initially check every 4 weeks to get a pattern of required maintenance. Filters are the heart of a clean evaporator coil and return air ducts. An impacted filter not only reduces airflow and reduces capacity of the system but it also allows particulate to pass through the filter and enter the return air duct and even landing on the evaporator coil where it builds up and eventually clogs the coil. This in turn may allow freeze ups and even compressor valve failure, resulting in an extreme costly repair bill.

8. Q. Can a unit be placed directly on the ground?

A. Most installations require the unit be bolted or secured to a concrete level or similar pad. In some locations there may be stipulations where the outdoor unit be so many feet above sea level.

9. Q. What is a heat pump?

A. A heat pump is an air conditioning system which has the ability to discharge the waste heat either outdoors or indoors depending on the demand of the owner. The heart of the operation of course is the compressor which takes the low pressure low temperature vapor and compresses it to a high pressure high temperature vapor. This is the vapor which is directed to either the outdoor coil or the indoor coil according to the owners demand. Unlike electric element heat the heat pump delivers more heat per watt of power consumed. Strip heating (straight element) will consume one watt of power and can produce the maximum of one watt of heat, whereas the heat pump will consume one watt of power and can produce 2.5 watts (more or less depending) of heat making them much more efficient. The heat pump is rated by C.O.P. (co-efficient of performance). The higher the number the more efficient it is. The air which is produced by the heat pump may not feel hot, in fact it is rather cool compared to oil or gas heating. Sometimes additional electric elements are staged on to assist with this situation where the owner wishes to feel some warmer air coming from the registers or grills. Occasionally, there may be some frost developing on the outdoor coil which needs to be removed. The unit is equipped with a defrost control which will send the unit back into the "air conditioning" mode for a short time to defrost the coil, then return back to the heat mode. During this defrost mode, the electric element will come on to temper the air so the owner will not experience the chill.

10. Q. I turn off the unit, but the indoor fan still runs for a while.

A. With the higher SEER (seasonal energy efficiency ratio) requirements, now at 13 for new units, manufacturers have designed circuit boards or similar to extract as much cool from the evaporator coil as possible. Many have a time delay on the off mode which will allow the blower fan to run after the compressor has shut down. Some also have the opposite feature included where it allows the coil to chill before the blower fan comes on thus giving a very cool initializing gust.

11. Q. What is a time delay relay?

A. A time delay relay is a solid state device which is triggered by one of two methods. Delay on make and delay on break are the two categories. Delay on make is the relay that starts timing the delay when it receives the signal, and delay on break start timing when it loses the signal. Both are available in various delay times and even with adjustable times where you can set spacing between starts of units rather than bringing all units on at the same time in the case of a demand meter spike scenario. Some areas may have a power company which gives the owner a demand device for billing credits and the demand device may have a 5-7 minute delay on make already built in, so a delay on break would be the most applicable relay to have, because if you have the 5-7 minute delay from the demand device a delay on make of 5 minutes would take the off time to 10-12 minutes instead of the 5-7 minutes. Choose wisely. Many compressors can not start if there is an imbalance in pressures from the condenser to the evaporator. All compressors with expansion valves rather than capillary tubes or orifice restrictors need a starting system relay and capacitor. The newer scroll compressors, rather than reciprocating, start already unloaded high to low side, and thus do not require the start relay and capacitor. All most all single phase compressors for air conditioning require the run capacitor to allow the motor to run efficiently.

12. Q. Is the use of R-22 banned as of 2010?

A. HCFC-22 if also refered to as R-22 or by one of its trade names, Freon@22. It is a popular refrigerant that is commonly used in a variety of refrigeration and air conditioning equipment. Starting January 1, 2010, the production and import of HCFC-22 for newly manufactured equipment will stop in the United States. The production/import limit will be set at a level that is suitable for servicing existing equipment.

Between 2010 and 2020, HCFC-22 and HCFC-142b will be produced or imported for the exclusive purpose of servicing existing equipment. As of January 1, 2015, as part of the phaseout of all HCFC's, the sale and use of HCFC-22 will be banned except for transformation or servicing refrigeration and air conditioning applications. EPA will not permit newly manufactued HCFC-22 to be used for charging new equipment. Starting January 1, 2020, the production and import of HCFC-22 will be banned entirely in the United States. Once this happens, only recycled/reclaimed or stockpiled quantities of HCFC-22 will be available for servicing existing equipment.

13. Q. What kind of filter should I be using?

A. In most cases, a good pleated 1" filter is fine. The fiberglass disposable filter that costs $.59, do yourself a favor, throw it away! There are very expensive filter systems that may be needed if special health problems exist.

14. Q. Should I replace my air conditioner because it is too old?

A. We are asked this question a lot. The answer may surprise you. In most cases we say no, depending on the overall condition of the machine. If it has been maintained over the years, and the useage that the machine has had, many factors are involved in replacing your air conditioning system, not just age.

15. Q. Should I turn my thermostat off when I am not at home or when I am on vacation?

A. No one wants to waste resources and cool an empty house, however with the relative humidity levels in Southwest Florida, it is best not to turn the air conditioner off completely. Set up the thermostat to a higher temperature 85 or so which will allow the machine to come on and dehumidfy the air and reduce the possibility of mold or warped drywall or cause structural damage due to high relative humidity.

16. Q. What do I need to know when buying a new air conditioner?

A. There are a few questions other than the bottom line price you need to know. If you buy a more efficient unit the cooling capacity will be the same as the less efficient unit, but the amount of energy consumed by the higher efficient unit will be less. Warranties need to also be considered in the final price, and what is warrantied for how long of a period. The labor warranty is also an important feature when purchasing a new air conditioner, some system installations have parts/labor warranties and others have only parts warranty. Compare before selecting your new air conditioner.

17. Q. What is a S.E.E.R.?

A. SEER is a standard of measurement of seasonal cooling efficiency under an average number of weather changes over a season. SEER stands fo "Seasonal Energy Efficiency Ratio". Where your old unit most likely had just an EER rating, today's units have a rating which is in essence the average of its EER over a standardized season. The higher the number, the more energy efficient the unit. Higher SEER rating air conditioners and heat pumps can pay for their added cost many times over because the consume less energy and have the same capacity for cooling. The savings continue year after year.

18. Q. How large an A/C unit do I need?

A. Standard practice is sizing a unit by calculating the heat load of the building, house or apartment. Several items must be considered such as insulation, windows, doors, appliances, machinery, occupants, and other heat loads. The major guidelines for load calculations are the Manual J, for residential, and Manual N for commercial buildings. Both manuals take in the same considerations while calculating the loads, but Manual J for residences normally is quite sufficient for the purpose. The square footage method will, in many cases, fall short for the required amount of heating and cooling.

19. Q. How long can I expect my A/C to last?

A. An air conditioner and refrigeration system lifetime depends on several factors. The major factor is maintenance, followed by unit quality, and climate. These all work together and form the lifetime of the air conditioning unit. Here in Southwest Florida the climate is warm to hot most of the time and has the Gulf of Mexico at our border. This translates into large run times and saltwater intrusion. Maintenance required of course to prevent corrosion of the heat transfer coil and cabinet corrosion is high. Washing and painting is a continual ongoing event. Other parts of the country have few running hours and not nearly as a corrosive atmosphere. Compare the air conditioner to a car.....if you drive your car for 16 hours a day, do you check the oil and fluids? Maintenance is extremely important. The indoor section starting at the air filter(s) should be checked on a periodic basis, and lubrication for motors, if not sealed bearing motors, should be light weight non detergent oils. Electrical connections should be inspected as well as controlling agents. Some air conditioning units may last as long as 20 years, but it is important to note efficiencies. The new 13+ SEER equipment is more efficient and costs less to operate than a 20 year old unit. The R.O.I. (return on investment) may save fuel bills in a five year period to pay for the replacement of an old unit.

20. Q. What is this Puron gas?

A. Puron gas is a trade name by the Carrier Corporation with the ASHRAE designated refrigerant number R-410A. The standard air conditioning system may not have pressure test ratings to be able to install the R-410A when replacing a R-22 system. R-410A; however is actually more efficient with BTU's per pound circulated, but the pressures are much higher than the R-22 air conditioning system, thus resulting in examining pressure ratings of the evaporator test schedules, and the interconnecting piping in the split systems (outside unit and inside unit). Most of the major manufactures have been leaning toward R-410A units. The refrigerant is an ozone layer friendly HFC (hydroflourocarbon) rather than the CFC (chloroflourocarbon) and HCFC (hydrochloroflourocarbon).