FAQ’s – HEATING
Question: What are the different types of heating systems?
Answer: Big question. There are many different systems in place today to heat a home and any attempt to cover each system will result in a book on the subject. To simplify things we will look at heating systems as a combination of two separate components, the distribution method and fuel. The different combinations of fuel and distribution systems make for the wide variety of systems on the market.
Heating systems come in all sizes, types and fuels. In residential systems there are basically two different distribution systems, forced air (ductwork) and radiation (baseboards). These systems can be fueled by one or more of oil, electricity, natural gas, propane, solar or wood.
For most purposes you can categorize home heating systems into two broad categories, furnaces and boilers. Generally speaking furnaces heat air and use a system of fans and ductwork to move that air around the house. Boilers heat water and use a circulator pump and piping to move the water through radiators, thus heating the home.
Question: Is there anything special I need to do to get my heating system ready for winter?
Answer:
Most heating systems are quite reliable and will provide you with quick, comfortable heat when you need it, providing you take good care of the system. We recommend that you check out your furnace BEFORE the first cold night hits. If you have air conditioning you should shut it down and cover it for the winter. (For more information on this see Getting Your Air Conditioner Ready For Winter under the Cooling FAQ section.) Follow these easy steps: Clean or change your furnace filter If your furnace or boiler has a pilot light, make sure it is on. Some homes are equipped with a “FRESH AIR INTAKE” that brings in fresh air from the outside for combustion. If your home has one, make sure it is not blocked and clean the outside lint trap. Set your furnace to the “heat” position and turn up the thermostat. Allow your furnace to run through a couple of cycles to make sure it is working properly. Do a quick visual inspection of the furnace area to make sure there are no items that could interfere with air flow or combustion. Call your service contractor to arrange for a professional cleaning and inspection.
Question: Is annual maintenance really necessary?
Answer:
Your heating system is a finely tuned piece of machinery that is designed to squeeze the most heat from your energy dollars. Your heating system operates for months on end and if one of the components of that system is not working in harmony with the rest of the furnace, you are losing efficiency and money.
Annual maintenance inspections often spot small problems before they become large, and very expensive repairs.
Annual maintenance can also spot dangerous operating conditions that could lead to production of carbon monoxide, which could be a potentially deadly situation.
When looking for a contractor to perform an annual maintenance inspection, make sure you know what you are getting. A comprehensive annual maintenance and safety inspection takes time and should be performed with care. If your service technician is in and out in just minutes, you may not be getting a comprehensive inspection. Make sure you get a checklist of the items performed.
Question: How do furnace manufacturers compute an AFUE?
Answer:
An AFUE (annual fuel utilization efficiency) rating is assigned to every furnace using a very complicated formula that takes into account many factors, such as fuel use, electricity use, and the fans used in the furnace. Usually, the manufacturer assigns the AFUE rating and then the AGA (American Gas Association) inspects the furnace and applies the formula to ensure that it lives up to its assigned rating.
Question: How can I tell if the heat exchanger in my furnace has cracks?
Answer:
You can’t. Most cracks in the heat exchanger occur in areas that are hidden away. Even if the cracked areas of the heat exchanger were visible, the cracks themselves are extremely difficult to detect by anyone without a trained, experienced eye. On older systems, we recommend the addition of carbon monoxide and smoke detectors.
Question: What causes the cracks to form in a furnace’s heat exchanger?
Answer:
In the normal course of furnace operation, the heat exchanger experiences repeated heating and cooling, which causes a corresponding expansion and contraction of the metal. Cracks will tend to form in areas of the heat exchanger that are weak, such as the areas that have been welded together at the factory. More weak spots and holes will form as a result of corrosion. Corrosion of the heat exchanger often signifies problems with the exhaust venting. What happens is that water in the exhaust, which contains carbonic acid, cools too quickly and condenses out, draining back down the chimney and onto the heat exchanger where the acid eats away at the metal. Corrosion can also be caused by the ammonia fumes from a nearby cat litter box (the litter box should be at least 15 feet away from the furnace).
Question: What does CFM stand for?
Answer:
CFM stands for cubic feet per minute, which is a measure of air flow. All air conditioning units have minimum CFM requirements which the furnace or air handler must provide for the air conditioner to function properly. CFM values are also important in the sizing of air cleaning and ventilation equipment, as well as in calculations of the pressure inside your home.