Masonry Magazine March 1966 Page. 26
SPACE HEATING
(Continued from page 25)
It is practically impossible to accurately recommend the exact amount of B.T.U. needed because of the ventilation involved in a construction project. In 1965, gentlemen, you have many manufacturers of portable heaters. I would like to name just a few to give you a general idea of where portable heaters could be obtained. We have The Champion Heater Company, The Master Consolidated Heater Company, Mr. Heat Heater Company, The Herman-Nelson Company, The Silent Glow Company, Airoil Company, John Wood Company, Kelly Company, Century Heater Company, Electro Jet Corporation. These are the major manufacturers of portable heaters today. Each of the companies I have mentioned will offer you the same approximate line of heaters that I outlined a few minutes ago.
For your information, there are three basic methods of building a portable heater for the construction industry. The three methods used are (1) the aspirator type of heater (2) the in-line, high pressure type heater, and (3) the Wayne burner, two sources of air, type of heater.
I will try to give you a run-down of each of these constructions for your general information and guidance. (1) We should discuss briefly the aspirator type of heater construction which is, in the industry, known by several other trade names that you might recognize. It is also called a syphon type of heater, A gulf burner heater, as well as the aspirator nomenclature. This is the newest of heater construction on the market today. The aspirator type heater is built by using the old Venturi suction principle that I know each of you have used in the years past with air-driven sludge pumps, air exhaust pumps for underground work. On the aspirator type heater, we have one motor that drives a small 3.5 C.F.M. vane type compressor that operates in a manner that pushes the air through a copper tubing and over a small orifice of a connecting tube that runs down into the fuel tank of the heater that forms the Venturi suction action. At this point, the suction action brings fuel up into the flow of air that is ejected into a combustion chamber through an injection nozzle and ignited to two standard high-voltage electrodes. This heater has been merchandised on the construction market for the past three years, and has been a successful heater.
The second type of heater that we have to discuss today, is what we call an in-line high pressure system heater. Gentlemen, if you were to check any oil furnace, in a residential district, you would find that the oil furnace is constructed in the high pressure system. What exactly does this mean? We use a Sunstrand or Barnes gear-type pump, a small orifice nozzle, we pump the fuel from the fuel tank into a copper tubing into the nozzle at a pressure of 100 P.S.I. Under this pressure the fuel is then injected through the small nozzle and becomes a fine combustible mix. We then have a circulating fan located directly behind the combustion chamber that both circulates the air, and also puts the proper amount of air into the combustion chamber for proper combustion. This is the oldest of heater construction on the market today, and still used by many of the heater manufacturers.
The third method of heater construction was basically designed by the furnace people in years gone by and that is the use of a Wayne type, or ABC, or new type of burner assembly, which is a self-contained assembly, designed to make a perfect fire! This assembly is self-contained. If you remove it from the heater, and connect it to a fuel supply, plug it into an electrical outlet, and turn it on, it will produce a perfect fire without being in the heater. This Wayne burner type of unit has also a high pressure pump and is a full high pressure system, but is unique because of the fact that it does have a squirrel-cage fan designed only to put the exact proper amount of air into the combustion chamber at all times. This fan, gentlemen, does not circulate heated air. Located directly above the combustion chamber, like a home furnace, is an "air scoop" which has a motor and fan that has only one function and that is to circulate the heated air created in the combustion chamber, out into the work area for immediate use by the workers.
Some points of interest that you might like to know is the problems in portable space heaters on a construction job. Being a portable space heater manufacturer myself, I find the greatest single problem is dirty fuel oil. It isn't at all abnormal for our service department to service a heater and find pounds and pounds of grit, sand, dirt, and all types of foreign matter in the fuel tank, that has been put there by the workers with dirty pails, etc.
As I mentioned in all three cases, in all three different types of heater construction, we talked about nozzles and each of these nozzles are designed to atomize fuel through high pressure. These nozzles, gentlemen, are so fine that you wouldn't hold the nozzle in your mouth and blow through the orifice. Because of this, dirt is the critical problem on everyone's heater, and you should take immediate steps, if you are using heaters on your project, to see that the fuel is kept constantly clean and in a proper place where it cannot get dirty.
The second most common problem on construction jobs is the problem of low voltage. All of the heaters that have talked about are equipped with electric motors for both running the high pressure pumps, and for circulating air, and with these motors, it is extremely important that the R.P.M. be maintained, as you already know voltage drop on a construction job will result immediately in a slow-down of your electric motors, not only on your heaters, but on saws, lights, etc., and the end result will be burned out electric motors. On a portable space heater the results are even more drastic than this. With low voltage conditions on any heater built on the market today the exact amount of air in the combustion chamber is important in having a clean smokeless fire. With low voltage the fan slows down, reduces the air input, and the result is fumes and smoke.
Any time that your unit smokes or fumes badly, you should first check immediately to see if the unit has run out of fuel and secondly, do you have proper voltage to the unit.
The third major problem that we encounter, is the problem of ventilation. A portable space heater is an open flame type heater that demands a certain amount of oxygen in the air for its constant proper function. If a room is closed tightly, and the heater is then started and allowed to run without proper ventilation to bring more oxygen into the room, will result in a carbon-monoxide condition that can be extremely harmful to all human beings, and animals and furthermore will create a dense smoke out of the heater, because it is being starved for proper oxygen to burn properly.
Gentlemen, I can assure you that portable space heaters are extremely safe if used in the proper manner, and with good judgement and should be, by all means, used on every construction job, from the first sign of cold weather through the end of the winter. Portable heat on your project can increase your profit dollars.
MASONRY
March, 196