Most heating systems in atlanta and across the nation use forced hot air in today residential homes.Because most air conditioning systems require forced air, the air handler can be used for both heating and cooling.It is more economical to install a single air delivery system than two.Hot air systems area availiable in a wide range of systems styles and capcities.

Most forced hot air systems are fossil fueled.Most common used in residential homes are hot air forced system as a cabinet mounted furnace installed in attic,or basements,or crawlspace.Proper venting is very important in the fuels combustion process the by products are removed from the heat exchange area and in to the venting flue and out of the building enevolope.Furnances are availiable for horizontal,vertical upflow,and vertical downflow applications.The central forced air heating used to heat a flow of air is the furnace.Most furnances are controlled by space thermostat.When heat is needed the burner starts immediately,but the fan does not start to distribute the air until the heat exchange temperture rises to around 110*F.

The blower starts when an internal thermastat(called a limit control)senses the heat exchanger is properly heated.When the space reaches temperture setting unit will cut-off.The fan is installed upstream of the exchanger for an important reason.Air pressure just past the fan is the highest than any where else in the system.

Today homes use indoor air for combustion and to help the flue draft.Under some conditions the fan can draw air down the chimney (if one is in the home) and into nearby return inlet registers.This can cause improper combustion and venting and allow these gases enter into home.Constant improvments have been made through the years in the heat exchange area.I would always recommend a inspection if a new unit has been installed to assure the contractor followed all the standard building installation code.If not when or if you go to sell your home you will be stuck with correcting the mistakes.I'm not trying to bad mouth good companys,but there empolyees will rush a job or take a short cut because they know you will never no the differance.

The split system air condition is the most widely used in residential applications.This includes central split direct expansion units and modular systems,split systems have their compressor,and usually condenser ,seperate from the evaporator.They work with a air handler and duct system.Central systems are used in residential and commercial buildings.These systems integrate well with forced air heating.Common controls make them eassier to operate.

Air to Air Heat pumps

A special form of electric heater is the heat pump.There are two types of heat pumpms:air to air and water source.Air to air are widely used in residential homes..Heat pumps are specialized air conditioners that move heat energy into or away from a space.The system can be reversed to cause heat to flow from spaces to the outside(like a regular A/C) or from the outside to the inside.This is considered its heat pump mode.

Air to Air heat pumps have two refrigeant coils and reversing valve.When cooling is needed,the indoor coil functions as the evaporator and heat is removed from the inside space.The outdoor coils functions as the condenser and the heat removed inside is discharged outside.

Reversing the flow of refrigerant swaps the coil's functions.The outdoor coil becomes the evaporator and absorbs heat from the outside air.

Forced Warm-Air Heat
Caring for the Forced Warm-Air Heating System
Balancing the Heat
Setting the Fan Control

Low installation cost, fast heat delivery, and reliability make forced warm-air systems a popular heating choice. The system is versatile and lends itself to the addition of central air conditioning. In this system, a blower pulls air from the rooms into the cold-air return and return duct, through a filter, and into the furnace. There the air is heated. It then flows back to the rooms through the warm-air ducts and registers.

Caring For the Forced Warm-Air Heating System
To ensure trouble-free operation, service the system as follows:

Clean or replace the filter monthly during the heating season.

Brush and vacuum heat exchanger surfaces annually (see owner's manual for instructions).

Clean the blower blades at the start of each heating season. Add a few drops of motor oil to each oil cup if your blower is equipped with them.

Check and adjust the belt alignment and tension if your furnace has a belt-driven blower. To replace a worn belt, loosen the motor adjustment bolt, remove the old belt, and attach a new one.

Examine the ducts annually for leaks; seal any leaks with duct tape.
Balancing the Heat
If some rooms are too hot or cold, try adjusting the dampers in the registers and, if your system has them, the dampers in the warm-air ducts.

Leaving the thermostat at one setting, let the system run for 3 hours to stabilize the temperatures. Open the dampers wide in the coldest rooms. Then adjust the dampers room by room until temperatures are balanced. Wait half an hour after each adjustment before rechecking or readjusting.

Speeding up the blower may help heat chronically cold rooms. Adjust the motor pulley of a belt-driven blower or, for a direct-drive blower, change the electrical connections (see owner's manual).

Setting the Fan Control
If you're chilled by a blast of cool air when the blower turns on, try adjusting the fan control.

CAUTION: If your furnace has a combination fan and limit control, do not touch the pointer on the limit control side. This pointer turns off the furnace if the maximum allowable air temperature is exceeded.
As the blower turns on, hold your hand in front of the warm-air register farthest from the furnace.

Ideally, your hand should feel neither cooler nor warmer.
If it feels cooler, uncover the control and move the fan control's ON pointer a few degrees lower.

To adjust the temperature of the air coming out of the registers, move the ON pointer to set the temperature at which the blower turns on, the OFF pointer to set the temperature at which it turns off.

  
Safety warning concerning the possible failure of certain flexible gas connectors that supply gas from supply pipes to applia nces such as stoves, dryers, room heaters, hot water heaters and furnaces.
These flexible connectors are made of corrugated metal tubing-newer models being made from stainless steel or from brass that has been coated with plastic or epoxy. Most older connectors, however, were made from uncoated brass. Some of these uncoated brass connectors have a serious flaw in the way they were made. Solder was used to braze, or join the flexible brass tubing to the end pieces. Over time, the brazing can fail, causing a serious gas leak. This could lead to an explosion or fire.

These brazed uncoated brass connectors have not been made since 1976, but many of them are still in use. The older these connectors get, the greater the possibility of failure. It is very difficult to see whether a flexible connector has been brazed, so don't take any chances. If you have an uncoated brass connector in your home, it is recommended to be replaced with either a new stainless steel connector or a new plastic coated brass connector. It's a good practice to replace any flexible gas connector which is more than 1 0 years old. This is because flexible connectors are not meant to last a lifetime. Older units can wear out from too much moving, bending, or from corrosion.

Locate your natural gas shut-off valve. If you can, check your flexible gas connector without moving the appliance attached to it, to see if it is an uncoated brass connector. If you cannot make this check without moving the appliance, we recommend that you have Gas  company inspect the connector for you, and if necessary, replace the connector. Moving the appliance could strain the connector possibly causing a gas leak. If the appliance must be moved, it's best to have a professional on hand to do it.

If you think you have a gas leak in your home—from a flexible connector or any other source, please call 911 for emergency service from the fire department. If the odor of gas is strong, leave immediately and make the call from a neighbor’s telephone or a pay phone. On the way out, open up windows and doors, and alert others to leave. Make sure not to operate appliances or turn light switches on or off.