Facts and FAQs About Heating and Cooling
Top 5 Things Your Air Conditioning Wants You to Know
Some Common Definitions
Air Cooled: An air cooled air conditioning system uses outside air to dissipate the unwanted heat removed from the indoor environment.
Air Conditioning: An air conditioner (often referred to as AC or HVAC) is an appliance, system or machine designed to alter the air temperature and humidity within an area (can be for cooling or heating) by refrigeration, evaporation, heat dissipation or absorption. Also knows as a way to transfer heat from one location to a less objectionable place.
Temperature in a space, home, house, office or building can be controlled by air conditioning. The desired or target temperature varies greatly depending on the needs and wants of the occupants or even the product or items located in the conditioned space. For human comfort, studies have determined that between 72° Fahrenheit (F) and 78° F is comfortable in the summer and 68°F to 72°F is comfortable in the winter.
In humid areas like South Florida, controlling the humidity in indoor environments is just as important to comfort as controlling the temperature. We would like to maintain humidity levels in South Florida at around 50% Relative Humidity (RH.) We generally find most people are satisfied with levels between 40% and 60% RH.
Air Handler Unit: Usually the air handler unit is the indoor component of a split system that houses the evaporator and fan motor. The conditioned air circulates through the cooling coil to absorb the unwanted heat and then returns the air to the indoor environment.
BTU: A Btu is defined as amount of heat required to raise the temperature of one 1 pound (0.454 kg) of liquid water by 1 °F (0.556 °C) at a constant pressure of one atmosphere.
Condensing Unit: Usually the condensing unit is the outdoor component of a split system that dissipates or rejects the unwanted heat.
Duct: Ducts are used in heating, ventilation, and air conditioning (HVAC) to transport air. These needed airflows include: supply air, return air, make up air and exhaust air. Ducts also deliver, most commonly as part of the supply air, ventilation air.
Ductless System: A ductless system is a system where the indoor section is mounted inside the living space, eliminating the need for duct work.
Duct Work: A duct system is often called duct work. Planning (‘laying out’), sizing, optimizing, detailing, and finding the pressure losses through a duct system is called duct design.
Electric Heat: Electric heat defines a process where air is passed over electrically energized heating coils before distributing the air in the space. Electric heat strips are usually located in the air handler, duct work or the evaporator section of an air conditioning unit. Rated in kilowatts (KW) where 1 KW equals approximately 3,412 BTU/h.
Freon: Freon is a trademarked name commonly used interchangeably for refrigerant.
Heat Pump: While a heat pump can be a system that pumps heat in one direction, typically in the air conditioning field the term is used to mean that the system can be reversed when needed to remove heat or to add heat. Another term commonly used and is more appropriate is reverse cycle.
Humidistat: A humidistat is an instrument that measures and controls relative humidity. A humidistat is also known as hydrostat.
Humidity: Air conditioning equipment as a byproduct of its operation reduces the humidity of the air conditioned by the system. The relatively cold evaporator coil condenses water vapor from the processed air, much as a cold drink will condense water on the outside of a glass. The water is drained away to a less objectionable place.
Creating a comfortable environment for occupants can involve many different variables and while temperature and humidity are important factors, many other items should be considered. Items like indoor air quality, dust, gases, lighting, mold, mildew, odors and a host of other parameters that have been shown to make the indoor environment uncomfortable.
Package System: Typically means the condensing, evaporation and air handling sections are combined into a single system. Usually an air cooled package system is located outdoors or is ducted to the outside. A water cooled package system may be located indoors and connected to water through piping.
Refrigerant: A refrigerant is a compound that can readily absorb heat at one temperature and then is compressed to a higher temperature and pressure where it changes state and discharges the absorbed heat.
Return Air: Return air is typically air that is drawn from a space, conditioned, recirculated and resupplied to the indoor environment.
Split System: Typically means the air conditioning system has two pieces that are connected by refrigerant piping that transfers the heat from one unit to the other.
Supply Air: Supply air is the conditioned air that is delivered to the indoor environment for the purpose of providing a desired effect to the space.
Thermostat: A thermostat is a device, as in a home heating system, a refrigerator, or an air conditioner, that automatically reacts to temperature changes and activates the system to control the temperature in the indoor environment.
Ton: A ton is 12,000 BTU’s of cooling.
Water Cooled: A water cooled air conditioning system uses a remote source of water to dissipate the unwanted heat removed from the indoor environment.
What should my thermostat setting be in the summer?
The setting is at the discretion of the user. However, the lower the setting, the more energy is consumed. So a balance needs to be achieved to satisfy the occupants at the highest comfortable setting. Typically when the space is occupied, the recommended setting is between 72°F and 78°F.
What should the settings be when I am away from home?
When the occupants are away for more than 14 days, we recommend setting the temperature at 80°F and running the unit for a 2-hour period daily to reduce the humidity. This can easily be accomplished now with the use of a programmable style thermostat.
Should I be concerned about humidity when I am away?
Absolutely! Mold can begin inside your home when the relative humidity (RH) exceeds about 65 percent. A humidistat, which directly controls indoor relative humidity, is one way to prevent mold. Dehumidifiers and some central air conditioners have a built-in humidistat that tells the system to dehumidify the air to a desired point.
Do I need to have a Humidistat?
There is no easy answer to this question. Before the days of programmable thermostats, it was a method used to control the humidity when no one was occupying the space and temperature control was not the priority. This method wasn’t always successful depending on a number of indoor and outdoor conditions but usually provided acceptable results. Recently some of the newer air conditioning systems now use humidistats to provide better humidity control and these units should have a humidistat.
How else can I control humidity?
Now with programmable thermostats and portable dehumidifiers, there are lots of options available to control humidity in an unoccupied space. Consult your air conditioning expert to determine the best solution for each individual application.
How often should I change my air filter?
That is another great but difficult question. There are many different types of filters and people live different lifestyles that will affect filter change interval.
Here are some basic guidelines on when to change your filter:
* Traditional Fiberglass or Polyester: Monthly
* Washable/Reusable: Washed out monthly and reused
* Ordinary Pleated: Every 2 – 3 months
* Deep Pleated: Once or twice a year
* Pleated, Permanently Charged Electrostatic: Every 2 – 3 months
* Electronic Air Cleaner: Cleaned regularly (at least once a month)
Where is my A/C air filter located?
The location is usually determined by the design and layout of the system and the home and varies greatly from home to home. First place to look is near the air handler (indoor) unit. Look at the bottom of the unit for a small door or cover. Some units have air filters behind the bottom panel in front of the cooling coil.
The next thing to look for if you have a package unit or if the unit is located in the attic is a return air grill with a track for the filter. The return air grill will have release clips to drop the grill down and expose the filter. Return air grills can be in the wall, ceiling or floor or in the platform under the unit.
Don’t forget to make a note of the date you replaced your filter.
How often should I have my A/C system checked?
Have your system checked at least once a year. Climate Control Services and most manufactures recommend an annual tune-up. Maintaining your system will extend the life expectancy, ensure dependable operation, minimize electric consumption and shorten run time. And most important for South Florida residents is to clean and service the condensate drain to reduce the chance of a damaging water leak.
How often should I need Freon (refrigerant)?
You should never need to add Freon to a system. Small leaks and annual serving of the equipment may require that a small amount of Freon be added occasionally. This should be a very rare occurrence. If you have to add Freon to the system often, or in large amounts, then a leak test should be performed to locate the cause of the leak, and repairs made to permanently seal the leak.
How often should my Air Conditioning system need to be replaced?
Most studies indicate that in the Southeast, systems will typically last an average of 10-12 years. Proximity to the ocean can reduce this time due to the intense effect of salt corrosion.
What is SEER? What SEER should I buy?
Seasonal Energy Efficiency Rating, or SEER, is a rating system adopted by the federal government to establish efficiency standards for air conditioners and heat pumps. The more efficient the system, the less it will cost to run during the season. The SEER standard is currently 13 SEER, and we have systems with efficiencies up to 23 SEER.
What SEER is my unit?
The average 12-year-old-air conditioner is less than an 11 SEER.
Should I buy the highest SEER I can find?
Occasionally we have found a return on investment on the highest SEER units. But a majority of units we install, with the highest return on investment, fall into the middle range of available SEERs. A lot of factors should go into that decision and that is where a qualified and experienced company can help you make the best decision.
Is a bigger air conditioning system better?
Over-sizing an air conditioning system is not recommended. A larger air conditioner uses more electricity to start, and therefore if oversized will cycle on and off more frequently and use more electricity. Over sizing will reduce the system’s ability to properly control temperature in your home and will cause large swings in temperature. Most importantly for South Florida, an oversized unit will not properly control humidity levels in your home
How often should I clean my ducts?
Most residential duct cleaning should be performed about every five years or after a renovation. Ducts do get dirty, but the majority of the time it is the furnace motor, blower wheel, heat exchanger and evaporator coil that become dirty and clog up the system. These can cause breakdowns and increase energy usage. It is very important to clean the equipment at the same time the ducts are cleaned.
What is the best brand of unit?
All the major brands are very similar in quality. We service and sell all the major manufacturers and they have made major strides in reliability in the last decade. At Climate Control Services we believe a more important factor is the application. Different locations, needs and wants should drive the decision of what brand to invest in. The many different locations require units that will fit with minimum modifications to the structure. Some homes may need a brand that provides more humidity control than another home.