Heating and Cooling
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Heating & CoolingThe heating and cooling system in your home should give you many years of service with proper maintenance. Preventive maintenance will lower your energy costs, prevent costly repairs and prolong the life of your system. Regular maintenance will ensure that your system is ready to heat and cool your home when needed. There are a variety of systems for heating, ventilating and cooling your home. Here we discuss the most common systems and their individual components. Review all sections that apply to your home. For specific information on how to maintain the system in your home, see the manufacturers’ appliance manuals for the equipment in your home. If you are missing one or more original appliance manuals, contact the appliance manufacturer and ask for a replacement manual. Most manufacturers should replace missing manuals. The suggestions listed below are a reminder that your home’s system must be maintained regularly. Always follow the manufacturer’s maintenance specifications . Professional Maintenance The contractor that installed your system or your local oil or gas distributor should be qualified to maintain your system. You can look for heating and cooling contractors in the yellow pages of your local telephone book. Clock thermostats and multiple-setback thermostats can be adjusted to maintain different temperatures at different times of the day to conserve energy. If the house is empty you can set the units for lower temperatures. Maintenance 1. Dust. Remove the thermostat’s cover and dust the inside surfaces and any metal coil with a soft brush. 2. Contact Points. Clean metal contact points by working a piece of heavy bond paper or thin card stock between the contact points and blowing the contacts clean. 3. Liquid Mercury Contacts. The previous step is not necessary if the unit has a liquid mercury contact enclosed in an airtight glass tube instead of contact points. 4. Switch Contacts. Clean any metal switch contacts along the top or edges of the unit with a cotton swab moistened with alcohol. 5. Alignment. Check alignment with a level and adjust as necessary. 6. Calibration. Check temperature readings for accuracy and adjust as necessary. Forced Air Heat Your forced air heating system requires comprehensive annual maintenance by a professional heating contractor at the beginning of each heating season. In addition, you should follow the simple maintenance suggestions discussed below to keep your system operating at peak performance. Air Filters The first step in inspecting your air filters is to locate and remove the metal panel covering the filter or filters. The cover panel should be located near the heating system’s blower. Next, slide out the filters. Clean or replace the filters with new filters of the same size. Slide the new filters into position according to the air-flow directions on the filter. Finally, replace the cover panel. Regular inspection, cleaning and replacement of your furnace filters will reduce your heating bills and prolong the life of your heating unit.
If your system has duct dampers, they should be found where one duct branches from another. The damper handle shows the direction of the damper vane. A damper is fully open when the handle is parallel to the duct. It is fully closed when the handle is perpendicular to the duct. Increase air flow to cold rooms and reduce air flow to overheated rooms. If you have problems adjusting the heat to your satisfaction, consult your professional heating contractor. Gravity Air Heat Hot Water Heat Water can circulate through the system by gravity (lighter, heated water rises to displace heavier, cooler water) or by circulating pumps. Distribution piping can be laid out in a variety of arrangements. Some combination of thermostats, aquastat controls (on/off control based on preset water temperatures), relays and manual controls will control the system. Some systems divide the home into separate heating areas or “zones.” Your heating contractor or gas or oil supply representative can identify and explain the particular features of your hot water system. Although the theory is simple, you have a complicated system. Your system must be inspected and serviced by a professional heating contractor annually. Careful operation and periodic home owner maintenance are also required for safe, trouble free operation. If you have any questions or concerns regarding the operation of your hot water or steam heating system, call your professional heating contractor. Dirt, dust and obstructions interfere with the heat transfer from the radiators or convectors to the room air. Clean the radiators or convectors with a vacuum brush attachment regularly. If a radiator cannot be cleaned with a vacuum brush attachment, spread damp newspapers under the radiator and clean with a radiator brush. Remove any drapes, furnishings or other objects obstructing air flow around your radiators or convectors. Do not place anything on top or in front of your radiators or convectors. Air trapped inside a radiator or convector, can interfere with heat distribution. Some radiators and convectors have automatic air valves that bleed air from the units. If yours do not, they should be bled manually at the beginning of the heating season and after adding or removing water from the system. If a radiator or convector will not heat properly, bleeding the unit may solve the problem.
Your system heats water under pressure. An automatic pressure relief valve guards against excessive pressure. This safety control device will open, if needed, to release pressure and prevent serious damage. Steam Heat You should maintain your steam heat system similar to the hot water system discussed above. Steam systems must be serviced by a professional heating contractor. There are some differences between the two systems. Steam heat systems do not have pumps and pump controls to maintain. The steam boiler’s water level should be monitored periodically. In addition the low-water cutoff should be flushed once a month to prevent buildup of sediment. Ask your contractor how to maintain your system throughout the heating season. Gas Burner In a gas system, an automatic gas valve opens when the thermostat calls for heat. Gas flows into a manifold and through venturi tubes where the gas mixes with air. A pilot light then ignites the air-gas mixture when it emerges from burner ports. The burning gas produces heat. A thermocouple next to the pilot light closes the gas valve if the pilot light goes out. This prevents unburned natural gas from accumulating and creating a fire hazard. If the thermocouple is faulty, the pilot will not light. Pilot lights can be electric or gas pilots. If you have problems with an electric pilot, call your professional heating contractor. You can clean and re-light a gas pilot by following the instructions printed on the front of the boiler or furnace. Some home owners turn off their gas pilot lights during the non-heating months. This may save energy but can create other problems. Keep the pilot burning all year to reduce condensation within the system and prevent corrosion.
A proper draft over the fire box is important for efficient operation of either oil burner. Most oil burners have a draft regulator mounted in the exhaust stack near the boiler or furnace. The regulator contains a small damper that opens and closes automatically to maintain the proper draft. Professional Maintenance Your heating contractor should do the following: 1. Burners. Clean the burners and adjust as necessary. 2. Heat Exchanger. Clean heat exchanger surfaces. Inspect to ensure there is no deterioration allowing poisonous exhaust gases to mix with indoor air. 3. Flue. Clean flue passages and inspect for exhaust gas leaks. 4. Efficiency Testing. Test burner efficiency and adjust as necessary. Electric Elements Have a qualified professional maintain your electric boiler or furnace once a year. Likewise, if you have any problems with the electric heating elements, call a qualified professional. Heat Pump The most common heat pumps are air-to-air systems. They extract heat from the outside air and transfer it to the inside air. Other systems include solar-assisted, water-source and ground-source heat pumps. The principles for air-to-air systems discussed below also apply to other types of heat pumps. It may seem hard to believe that heat from outside air can heat your home during freezing weather. As long as the air temperature is greater than absolute zero, -460 degrees F., there is some heat in the air. At 32 degrees F., air possesses 88% of the heat that it has at 100 degrees F. Operation The warm liquid then, passes through an expansion valve, reducing the refrigerant’s pressure, expanding its volume and lowering its temperature (the reverse of compression). The cold refrigerant is ready to absorb heat from the outside air again and repeat the cycle. The air at your registers may seem cool during the heating cycle. This is because a heat pump does not deliver sudden bursts of hot air like conventional furnaces. Instead, it delivers a more constant flow of 85 to 90 degrees F. air at a higher velocity. The air feels cool because it is less than your body temperature. The air is sufficiently warm to keep you comfortable. Air Conditioning Supplemental Heating Outdoor Unit Do not allow snow, grass, clippings, vines, shrubs or other items to accumulate on or around the outdoor unit. Do not stack or store items on or around the unit. Maintain a minimum 12 inch clearance between the outdoor unit and snow banks and other obstructions. It is important to allow air to flow to the unit unrestricted. Make sure that no one steps on the copper tubing between the indoor and outdoor units. Do not place or hang items on the tubing either. The heat pump may malfunction if kinks or dents in the tubing causes refrigerant to leak or restricts refrigerant flow. Repairing or replacing the copper tubing can be expensive. Professional Maintenance 1. Blower. Inspect, clean and oil the indoor blower motor and blower wheel. Permanently lubricated motors should not be oiled. 2. Coils. Inspect and clean indoor and outdoor coils. 3. Drains. Inspect and clean the indoor coil’s primary and auxiliary drain pans and drain lines. Unplug if necessary. 4. Wiring. Inspect wiring for loose electrical connections, discolored contacts and terminals and bare or frayed wiring. 5. Performance. Check the system’s performance and adjust as necessary. Electric Baseboard Heat Electric baseboard systems convert electricity to heat by forcing large amounts of electricity through a thin, highly resistant wire, causing the wire to become warm. The wire, or heating element, runs through a ceramic-lined metal tube surrounded by metal fins. A natural draft draws air through openings at the bottom of the baseboard unit’s exterior housing. The air flows over the finned tube, picks up heat and rises through openings at the top of the housing to heat the room. An alternate electric baseboard heating system uses fluid in a sealed tube. The heating element heats the fluid, which heats the tube and fins, which heats the passing air. The fluid retains heat and continues to warm passing air for a time after the thermostat turns off power to the heating element. Controls Most electric baseboard units have a temperature cutoff control. This safety device prevents the heating element from burning out when obstructions block air flow to the unit. Electric Ceiling Heat Your ceiling system converts electricity to heat by forcing large amounts of electricity through thin, highly resistant wires embedded in the ceiling. The wire becomes warm and radiates its heat to the room below. Thermostats control the flow of electricity to the ceiling units. Each unit has its own thermostat mounted on a wall. The individual thermostats allow rooms to be heated as needed. This “zone” heating is more efficient than heating rooms that are not being used. Drilling nails, holes or screwing hangers through the ceiling can sever the thin wires and damage your system. If you ever have a problem with a ceiling unit, call a professional electrician. Air-Conditioning Cooling takes place when a cold liquid (-20 degrees F. boiling point), such as Freon, passes through an evaporator coil. The refrigerant absorbs heat from the inside air and begins to boil. An electric compressor pumps the vaporized refrigerant under pressure to a condenser coil in an outside unit. A fan cools the refrigerant in the condenser. The refrigerant passes through an expansion device. The rapidly expanding refrigerant then cools to form a cold liquid. The refrigerant, which is now cold returns to the evaportor coil to repeat the cycle. For Heating and Cooling Maintenance in (800)-250-2423 or (704) 545-2847 |
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