Types of Furnaces
In the United States, the type of furnace people use depends on cost and the local climate. Some furnaces are most efficient in mild winter climates, but in regions with long winters, another type of furnace works better. Here is a description of the most common type of home heating furnaces:
Gas
Gas furnaces are good for cold climates but can be used in any climate. Gas furnaces may be fueled either by natural gas or propane.
When the room temperature drops below the temperature set on the thermostat, a low-voltage electrical signal is sent to the furnace. The signal opens a valve and delivers gas to the burners and the blower turns on. It also triggers the furnace’s burner inside the combustion chamber. This creates heat in the furnace’s heat exchanger, a metal chamber around which the moving air flows. Once warmed, the warm air is pushed into the hot-air plenum and then out to the rooms through ductwork.
Heat pump
A heat pump does not generate heat; instead, it moves heat from one place to another. This technology is the same used in refrigeration and air conditioners. A heat pump is actually a system that can be used to either heat or cool a home. The equipment needed for this type of system typically consists of two parts: an indoor unit called an air handler and a heat pump, which is an outdoor unit similar to a central air conditioner. A compressor circulates refrigerant that absorbs and releases heat as it travels between the indoor and outdoor units.
Electric furnaces
Electric furnaces use electricity to power internal heating elements that generate heat for your home. They are considered high-efficiency heating sources. If electricity costs are high, however, the increased costs can offset any gains in heating efficiency.
Common signs your furnace needs repair
No matter which kind of furnace you have annual routine maintenance by a professional HVAC contractor will minimize the likelihood that you will need a mid-winter emergency repair. Nonetheless, breakdowns and unexpected mechanical failures do happen. Often, your heating system will give you some indication that it needs professional service. The warning signs are often (but not always) obvious. Here are some of the most common signs that you need to call your HVAC contractor for a diagnosis and repair:
1. Lack of warm air. The furnace is blowing cool air and not keeping the house warm. Call your HVAC technician. The problem could be a faulty thermostat, or it could be a more serious problem.
2. Lack of routine maintenance for more than one year. Pre-season annual inspections and routine maintenance by a professional are vitally important to keeping repair bills low and ensuring your system is operating at optimal performance levels. If a technician has not looked at your furnace in over one year, it is time to call for maintenance. Heating systems need regular attention and failure to do so can lead to premature breaking and unnecessary strains on your system.
3. Higher than usual energy bills. If you notice an increase in your energy bills without a comparable change in the outdoor temperature, do not ignore it. Higher bills are often a sign that your furnace is straining to keep up with the demands on it. It could need a relatively minor repair. If you ignore it, you could find yourself in need of a new system.
4. Short-cycling or running constantly. Short-cycling is when your furnace comes on and quickly goes off after a short period. It may be a sign that your heat exchanger is overheating and causing the system to shut down. Short cycling can be a sign that something is seriously wrong with your system. On the other hand, if your furnace runs without going off for long periods of time, service is warranted. Call your HVAC contractor for a service appointment.
5. House is not reaching the temperature on the thermostat. Your furnace may be running all the time, but you still feel cold. This could be a sign that your fan motor or a belt is worn out. You should call a professional technician to diagnose and recommend the best solutions.
6. Unusual noises. If your furnace is making strange noises, you should turn it off and contact an experienced HVAC contractor for service. A screeching sound can mean the blower or a belt has worn out. While banging or grinding sounds can mean the unit has broken internal components, but in all cases, the furnace needs repairs or replacement.
7. Unusual smells. If you smell gas, turn off your furnace and call a professional right away. You probably have a gas leak. Sharp, pungent odors emitting from your system may mean an electrical problem. Lingering musty, organic odors are an indication of mold growing in the system, which is itself a symptom of excessive humidity or moisture pooling where it should not be. Your system should be professionally serviced to pinpoint the problem and make appropriate repairs.
8. Age. A system that is over 15 years old that is experiencing these signs probably needs to be replaced. The average life span is 15 to 20 years. The cost of a significant repair to an older system may not be cost-effective when a new one will operate more efficiently and less expensively. Call your HVAC contractor to schedule an evaluation and possible replacement before the season begins.
9. Unusual amounts of dust. Your furnace has an air filter that removes airborne particles, such as dust mites, pet hair, and similar substances. The air filter needs to be changed once per month. A dirty air filter puts unnecessary wear and tear on the heating unit. If the filter is not changed for a long time, the damage to the furnace could be beyond repair.
Consult a reputable HVAC contractor
Don’t ignore the warning signs described above. Make sure your furnace evaluated and serviced by a reputable, professional HVAC technician before the winter months set in. Contact an experienced HVAC contractor and schedule an evaluation before winter sets in.