Oil Fired Furnaces

Fifty-year proven history of evolution.
Today's premium oil furnace product line on the market.
Quality product construction backed by strong customer service and support.

Oil Furnace Product Line Safety and Performance Comfort Efficiency The Heat Exchanger The Design Square Inches of Heating Surface BTU Capacity Welding Service Access for Cleaning and Inspection The Finish The Heat Exchanger Warranty The Refractory Chamber The Burner and Controls The Blower The Cabinet and Finish The Warranty

Oil Furnace Product Line
To meet the needs of almost unlimited home or business construction configurations and also BTU heating needs, furnaces must come in a variety of styles (directions of air flow) and BTU capacities. Some product lines of competitive brands of oil furnaces are very limited in the range of BTU capacities offered and also in the variety of styles. A typical home may require as little as about 50,000 BTU's (output) upward to 150,000 BTU's with 85,000 BTU's, likely, being the most popular size. Commercial size oil furnaces typically range from 125,000 BTU's up to 320,000 BTU's (output).
Styles of oil furnaces include basement and upflow models where the heated air is blown out the top of the furnace in an upward direction. Downflow furnaces, where the heated air comes out the bottom, are needed where slab construction is used. Horizontal, left or right, airflow models are commonly used in attics or crawl space applications.
As stated above, some competitor product lines are very limited in BTU and/or style offerings. These manufacturers, to overcome this, may fire the same physical furnace over several BTU sizes (see The Heat Exchanger section for a further explanation). Some manufacturers offer models that can be either laid down or stood up, but typically, with some compromises.
Thermo Pride's line of oil furnaces has evolved over fifty years and is probably the most complete line on the market. Models with dedicated airflow directions are available in upflow, downflow and horizontal styles and in a broad range of BTU capacities. Forty-six physically different models make up the complete Thermo Pride oil furnace offering, thus providing the capability of installation in virtually any application. This breadth of product line reflects the long term Thermo Pride commitment to oil furnaces and is a testimony to the overall popularity of the Thermo Pride brand.

Safety and Performance Independent Certifications
All Thermo Pride oil furnace models are Underwriter Laboratory (UL) certified for safety and conform to Thermo Pride voluntarily participates in the Gas Appliance Manufacturers Association (GAMA) sponsored efficiency certification programs which verify manufacturers' equipment efficiency ratings in accordance with federally mandated test procedures.

Comfort
"Temperature rise" is the difference in temperature of the air from the point where it enters the furnace to the point where it exits the furnace. The higher the temperature rise, the greater the warmth of the air when it enters the rooms of the home. Some brands of furnaces have a temperature rise as low as 50°F. Others are up in the 70°F temperature rise area. Thermo Pride has set a 70°F temperature rise as standard across its full line of oil furnaces. (See The Blower section for a further explanation on temperature rise).

The Operating Efficiency
The US Department of Energy has established minimum efficiency levels for oil furnaces. Efficiency is reflected as a % and is referred to as Annual Fuel Utilization Efficiency (AFUE). The minimum allowable AFUE is 78%. Oil furnace manufacturers, for the most part, have stayed below 85-percent AFUE, as a maximum, to lessen the likelihood of chimney moisture problems resulting from exhaust vapors that are too cool. The higher the efficiency, in other words, does not necessarily translate to mean the better the furnace. There are still other considerations such as comfort and noise (see The Blower section for a further explanation). Thermo Pride, as a premium oil furnace built to provide long term comfort and value, offers models typically delivering about 82% AFUE. Thermo Pride believes this level of annual operating efficiency provides the best results in the form of proven technology, home or office comfort, reliability, and operating cost value. By the way, if the typical home fuel oil heating cost for a year is $750 then each 1-percent AFUE difference represents about $7.50 of annual fuel cost.

The Heat Exchanger
The heat exchanger is the heart of a furnace. It is where the fuel is burned and the resulting heat transferred to the air, which circulates through your home or place of business. What are some key considerations regarding a heat exchanger?

Metal thickness.
The heavier (thicker) the metal the more durable and corrosion resistant the heat exchanger. Thermo Pride oil furnaces are constructed of 13 gauge hot rolled steel. The lower the gauge number the thicker the steel. Some brands of oil furnaces use 17 gauge or 18 gauge steels which are about half the thickness of 13 gauge.

The Design
Most brands use round or square designs because they are easy to manufacture and, therefore, less expensive. Thermo Pride has used an octagon (eight sided) shape for over forty years. The very proven octagon design is durable, provides outstanding heat transfer and, as proof of durable performance, has been backed by a limited lifetime warranty, also for over forty years.

Square Inches of Heating Surface
Over recent times, some brands of oil furnaces have been down sized to become very compact. This has been done in the interest of reduced steel costs and to prevent taking excess space in the home. The reduced size may come with a compromise however, and that is reduced furnace durability and less comfort. Thermo Pride continues to only produce heat exchangers built with a greater amount of square inches of heating surface. The larger heat exchanger surface area allows a more even spreading of the heat within the heat exchanger metal which means there is less stress in the steel. There is also a more uniform transfer of heat to the air which means more comfort.

BTU Capacity
A number of competitive brands use the same size heat exchanger to cover a range of BTU capacities. This strategy keeps inventory quantities lower and production costs down. Thermo Pride, with the exception of its largest commercial size, uses a unique octagon shaped heat exchanger for each of its nine different BTU capacities. Each Thermo Pride heat exchanger is designed for its intended BTU heat rating and, accordingly, is not being fired at the high or low end of its capacity. In other words, Thermo Pride uses optimized heat exchangers sized for each heating capacity.

Welding
Some manufacturers only crimp the heat exchanger metal together. Thermo Pride manufactures its heat exchangers by hand. It uses gas shielded, wire arc welding on 100% of all joints. Wire arc welding allows deep penetration into the metal thus forming an extremely strong and leak proof joint.

Service Access for Cleaning and Inspection
Some competitive brand heat exchangers are designed such that access for proper inspection is almost impossible. In the most extreme cases the furnace must be significantly disassembled to even allow a proper inspection or soot cleaning. In other cases access is just plain difficult. Easy access means more accurate inspection ability and, when cleaning is required, a quicker service call. Thermo Pride heat exchangers have always incorporated two clean out ports. Removable covers, secured by brass nuts on steel studs (dissimilar metals are less likely to fuse together) allow easy access. The two cleanout ports are located behind an easily removable access panel.

The Finish
Most furnace brands apply no finish to the surface of their heat exchangers. Some manufacturers paint the outside surface for appearance reasons or for protection prior to the furnace being placed in operation, but the paint burns off the first time the furnace is fired. Thermo Pride applies a pure copper powder coating to the outer surface of its oil furnace heat exchangers. The copper powder provides further protection to combat damp basements or locations where humidity can be a problem. The copper, though it darkens in appearance after the initial firing, remains firmly bonded to the heat exchanger surface.

The Refractory Chamber
Ceramic fiber refractory chambers have been adapted by most manufacturers because of their lower cost, lighter weight and quick heat up/cool down characteristics. Thermo Pride, with the exception of its smallest and largest models, where physical size restrictions occur, uses ceramic clay refractory chambers. Ceramic clay chambers are almost indestructible. Some fiber chamber designs may "sag" or change shape over time due to their hot environment thus no longer delivering the heat exchanger protection nor complete fuel combustion provided by an intact chamber. Thermo Pride's two piece, ship lap ceramic clay design has been optimized and proven over forty years. Besides being highly durable and providing for very complete combustion of the oil, it also delivers more heat to the heat exchanger metal during the burner operating cycle. This increase in the useable heat exchanger area, where heat is transferred to the air circulating through the home, helps raise efficiency.

The Burner and Controls
Most competitive brands incorporate a standard Beckett burner with controls supplied by any of several control manufacturing sources. The standard Thermo Pride burner is also manufactured by Beckett, but with a few very different features namely a stainless steel air tube and a special ceramic fiber sleeve. These extra, premium features provide additional burner durability in the hot zone. Thermo Pride uses all Honeywell controls on its burners. These controls are industry proven and are readily available in the after market should a failure ever occur.
Most manufacturers ship their burner pre-installed in the furnace. Thermo Pride ships its burners as a separate item to be installed by the contractor. This arrangement insures that the burner is set up correctly relative to the combustion chamber thus eliminating any problems resulting from component shifting which may have occurred during shipment.

The Blower
The blower is the device which draws the air from around the home into the return air duct work, back to the furnace and then forces the air around the furnace heat exchanger (where the air picks up heat) and back out through the registers into the rooms of the home. All forced air furnaces have a blower, but there can be significant differences in the blowers used in the various brands on the market. Moving air is obviously important, but so is the temperature of the air and noise, two important considerations frequently devalued in some brands.
Let's consider temperature first since comfort is an extremely important consideration. The U.S. Government has mandated minimum efficiency levels for residential size oil furnaces. The higher the efficiency the better, right? Not necessarily. A small compact car can be very efficient (high miles per gallon), but may not provide other values such as comfort, safety, etc. The same can be true in furnaces. The most efficient models may not provide the temperature rise or quiet operation that most customers want.
So, how does this relate to the blower? Some manufacturers use smaller size blowers (cost less, more compact), but then must operate them very fast in order to move the necessary air. That can be bad. Small blowers operate at very high velocities. They do transfer the heat, but because of the velocities they do not provide the warmer temperatures that people seem to prefer. This translates to mean the furnace provides a lower "temperature rise" of the air which, in turn, means cooler air coming out of the registers. High velocity air movement also means the blower blades are turning at very high speeds, which means they can be noisier in operation. So, while high velocity air movement can help in the AFUE efficiency calculation, it may not provide the desired comfort and, likely, will be much noisier in operation.
A larger blower with a large wheel (the part containing the blades) can turn slower and yet still move the required air. A physically larger blower costs more, but can more easily provide the higher temperatures and quieter operation valued by most owners.At Thermo Pride large, oversize blowers are the tradition. Thermo Pride large blowers provide delivered air temperatures that can range from 100F to 300F warmer than the competition and that means greater comfort. Large blowers allow operation at slower speeds to deliver the same quantity of air as a small blower operating at a much higher speed. The slower speed blower operates more quietly with less mechanical and air noise. Although higher air temperatures have a downside of a one or two percentage point reduction in the annual efficiency (AFUE) percentage, that is only a $5 to $20 annual operating cost penalty. The improved temperature rise and comfort enjoyed by the owner easily justifies such a low cost differential.
Small, high velocity blowers or larger, lower velocity blowers are available either with a multi-speed direct drive blower motor or with a belt drive blower motor. Direct drive blowers are typically used where central air conditioning is or may be installed in conjunction with the furnace. Some manufacturers provide two, three or four speed direct drive blowers. The more speeds, the greater the flexibility of providing specific air moving needs. Thermo Pride only supplies four speed direct drive blowers and, again, in oversize versions. Thermo Pride, also, unlike many other brands, has belt drive blowers available on most of its models. Belt drive blowers can have their speed very fine tuned for a specific installation which can be an advantage in a pure heating or air conditioning application. Where both heating and cooling are part of the same system, direct drive blowers have become preferred by contractors in providing the varying air movement needs.

The Cabinet and Finish
The function of a furnace cabinet is to contain the heated or cooled air, furnish protection for the controls and other components inside the furnace, ensure owner safety by isolating hot internal parts and to provide a pleasing, easy to maintain appearance.
Most manufacturers use 22-gauge steel to produce their cabinets though some thinner metals are found in some brands. Typically, the furnace and cabinet panels are joined together with multiple screws. Increasingly many manufacturers are using pre-painted steel in their cabinets which means the steel comes to them already painted prior to being punched, notched and bent. Sheared or punched edges on pre-painted steel result in exposed, unpainted steel which, in turn, can lead to future corrosion.
Thermo Pride uses 22 gauge steel in all external cabinet panels but thicker 13 gauge or 16 gauge metals in the furnace bases, support panels (such as the blower deck) and in some brackets. For over forty years Thermo Pride cabinet side panels have been fabricated with interlocking joints. This interlocking design provides tight air seals, greatly reduced potential for rattles, plus it substantially strengthens the furnace with the use of minimal screws. Besides the interlocking panel design most Thermo Pride models incorporate rounded edges and corners which give the furnace a much more finished appearance as well as greater strength. Rounded corners are almost a Thermo Pride trademark having been used for over fifty years. If you are getting the impression that Thermo Pride furnaces are very much hand crafted, you are absolutely correct.
Rather than using pre-painted steel Thermo Pride electrostatically paints all casing panels with a heavy coating of metallic enamel paint. The paint is applied on both sides of all panels after all fabricating operations are complete to ensure that no bare metal, exposed edges exist. The enamel paint is baked on in a high temperature oven. The inside surface of exterior cabinet panels adjacent to the furnace heat exchanger are cover with 1/2" thick, nylon reinforced foil faced fiber glass insulation to retain maximum heat for distribution into the duct system.
Some competitive brands do not provide a burner enclosure (vestibule) as a standard feature of their cabinets. This saves them money in the form of less material and labor. At least one brand offers an optional, add on vestibule but this really costs more because it is a separate, stand alone item. Thermo Pride, on all basement, upflow and downflow furnaces incorporates a vestibule into its design. This approach adds little extra cost since four of the five panels involved are simply extensions of other required panels. The vestibule provides protection of the burner plus helps isolate any burner combustion noise.

The Warranty
Several brands of oil furnaces now provide a limited lifetime warranty on their heat exchanger and a one-year warranty on parts. The installing contractor typically covers any first year labor costs. These warranties are normally extended to the original purchaser only. Such heat exchanger warranties started being offered in the late 1980's as a marketing tactic aimed at matching the Thermo Pride heat exchanger limited lifetime warranty which has been provided for over forty years (proof that Thermo Pride heat exchangers are extremely durable). The Thermo Pride limited lifetime heat exchanger warranty applies to both residential as well as commercial applications. Thermo Pride also provides a five year parts warranty AND both the heat exchanger and parts warranty apply to the furnace regardless of who originally purchased it. In other words, if the home or business is sold the new owner inherits the Thermo Pride warranty. Thermo Pride offers optional five-year labor and ten-year parts and labor warranties to further round out the peace-of-mind that many owners want.
Together, the features reflected in Thermo Pride oil furnaces provide the value that owners desire. These features have evolved and been proven over the fifty plus years Thermo Pride has been in business manufacturing and selling premium heating and cooling equipment.

Last Updated Sunday, July 15 2007 @ 04:03 PM EDT|5,681 Hits