central air conditioning
Buildings and large infrastructures generally have central air conditioning. A central air conditioning unit uses a split system for its condenser and compressor. The evaporator is attached to an air handling mechanism or a forced air furnace. The whole system is housed in a packaged unit that is often located outdoors, such as a rooftop or an outhouse.
Cooled air is distributed to the different floors and rooms through air ducts. A tenant may raise or lower the temperature through controls located in each room. Some buildings do not have such temperature controls. Tenants will have to deal with the common temperature set for all floors.
There are advantages to using a centralized air conditioning system. With the unit located outdoors, tenants are not bothered with the ambient noise that comes with a running air conditioning unit.
A sophisticated filtering system also cleans the air circulated in the whole building. Through various return-air ducts, room air is continually pulled and filtered. Through this process, dust particles and even microscopic pollutants are weeded out from the circulating air.
A centralized air conditioning unit also allows building administrators and engineers to control the energy consumption and voltage requirements of tenants. With a centralized air conditioning unit, tenants need not plug in their own stand-alone air conditioning unit.
In cooling or controlling temperatures, it is important that you can determine and dictate the total temperature. This is because it is easier and more economical to cool rooms with consistent temperatures. With a centralized air conditioning unit, you can do such.
When choosing the right brand or model for a central air conditioning unit, consider its filtering ability. Circulating air must be kept clean and fresh. Otherwise, you will be spreading pollutants to all areas of your building.
To give your tenants utmost convenience, you may have to provide them with the means to control the temperature on their respective floors. You may have to work with an architect to equip each floor with built-in controls.
In a central air conditioning system, a refrigerant circulates through a loop of copper tubing that runs between an outdoor unit—the Condenser—and an indoor unit the Air Handler. As the refrigerant travels between the two units, it absorbs heat from the room and releases it outside. The compressor in the condenser is the “engine” that pumps the refrigerant around the loop. The blower in the air handler pushes room air past the evaporator coil which cools the air and causes it to release its moisture, which drops into a drain pan and is piped away. Central air conditioning can be combined with a forced-air furnace or can be packaged in with a hot water coil (called a hydroair unit) - both share the same blower and ductwork. In all cases, the system is provided with an air filter to remove dust, hair, and lint. Air conditioners are powered by electricity. Proper maintenance and service can help reduce the high cost of keeping your house cool. Keeping your filter clean prevents a dirty evaporator coil. If your system has the standard 1 inch thick filter, it should be checked every month when air conditioning or heating are in use to be sure it is clean. Deeper pleated “high efficiency” filters have a larger capacity and should be checked before the heating and/or cooling season and replaced if necessary. Outdoors, keep leaves, mulch and debris away from the base of the condenser. |  |
Central air conditioning systems perform two functions, they remove humidity from the air and they cool the air. When a system is first turned on in a hot house, the first thing the system works on is removing the humidity – this is called the “latent load”. Once the humidity starts to drop, the temperature of the air will start to lower – this is called the “sensible load”. Lowering both the humidity and temperature provide comfort. Central air conditioners work differently than window units. Central air drops the air temperature between 16-20 degrees each pass through the air handler. It takes a while for the whole house to drop down from elevated levels when a central air system begins to run. A window unit blows out very cold air from a single point so it is easy to cool one room in a hurry but it doesn’t travel far. A closely sized central system may only drop the temperature indoors one degree per hour on a very hot humid day. Oversizing the unit will help drop the temperature more quickly on these days but when the outdoor temperatures are more mild, an oversized unit won’t run often and the air will be cool but humid – not a comfortable feeling. The proper way to operate a central air system is to button up the house as tightly as possible and keep it that way. This will prevent humidity from leaking in and burdening the system with latent load. Raising the internal temperature is better from an operating efficiency standpoint. Keep the house closed and raise the thermostat so the unit only operates for short periods, thereby keeping the humidity under control. Continuously opening and closing up the house will force the system to remove humidity repeatedly. | |
