Tweaking the Oil Furnace
They’re the old American standby, oil furnaces. In many cities in the United States oil is the overwhelming favorite for heating buildings. It works well, but the price fluctuates—dramatically sometimes—so it pays to make sure that oil furnaces work efficiently, especially if you, and not the tenant, pays the heating bill.
The obvious first step is to make sure it won’t break on you. If they’re going to break, it will always be on the coldest Friday evening of the year before a holiday weekend. So if you have the service man come before the cold weather hits and work his maintenance magic on it, the furnace will likely blow heat without incident all winter.
Typically, the annual furnace maintenance consists of replacing the nozzle (whether it is required or not), replacing the oil filter and air filter, oiling all moving parts, checking the setting of the ignition electrodes and, depending on the company, removing soot from the furnace and lower chimney.
Your serviceman then runs the furnace for ten minutes or so to check the controls. While the furnace is running, he’ll eyeball the fire, listen to the way the fire ignites, look for evidence of fire instability, and perform some other checks that won’t appear on your bill. All that will assure him you won’t have to call him again that winter.
The furnace man has one objective: to see that the furnace will not break this year. He is not too much concerned about efficiency, just how well the furnace runs. You can handle the efficiency part yourself.
Sometimes tenants complain about cold spots or cold rooms. The furnace works fine, but doesn’t heat all units equally well.
Here are some things to look for:
–Registers that blow directly on the thermostat. That will make for cold rooms.
–No adequate path for the air to return to the furnace.
–Unequal heat distribution because too much air blows in some rooms, and too little in others. Adjust the dampers in the heat ducts so that less air blows in the warmer rooms. That will equalize the heating. To make sure you are doing the adjustments properly, buy four inexpensive thermometers to put around the house. That way you can tweak the adjustments of the dampers so that temperatures come out even.
Fans last a long time, and even a dirty one will push air through the duct work. As they get older and dirtier, though, the do it less efficiently. The more hot air a fan blows into the house, the less is wasted up the chimney, thus, the more efficient your furnace is. It’s easy to clean a furnace fan, just tedious.
The fan may not even be bolted down, sometimes it just sits on rubber feet, so you can remove it without difficulty for cleaning. Just make sure the power to the fan is off. Use a small stiff brush, such as a toothbrush, and thoroughly clean all the blades. The accumulation of dirt can throw the balance of the fan off, so when you’ve finished cleaning it may run quieter.
The Split Pulley
Some furnaces have what’s known as a “split pulley.” That’s a device on the motor shaft that allows you to change the speed of the fan by changing the size of the pulley that holds the belt that turns the fan. For best heating the fan should be adjusted for maximum speed.
Why would a fan be set for slower speed? In the past, maximum efficiency was considered less important than quiet operation, so they set the fans at slower speeds. Some people claim that a slower speed heats the second story of a house more efficiently and uniformly. The fact is, the more air you move through the furnace and the more air you stir up in the house, the more uniformly heated it will be.
Look for hot-air ducts passing through an unheated area. Even a four-foot length of air duct can create an amazing loss of heat. If you have heat ducts that run over bare earth in a crawl space, the heat loss can be extremely costly. You might be able to cut your heating bill in half by insulating the duct work. Just be sure that you don’t compress the insulation when you put it on—that reduces the efficiency.
All that done, the furnace guy comes and you check for little things that can make the oil furnace less efficient, and the re- pair calls from tenants, about the heating anyway, may stop completely. Imagine that!