There’s nothing new about waste oil heaters. What’s special is technology that doubles the heat output, accepts all types of waste oil and burns it cleanly, leaving almost no deposit.
The EnergyLogic company in Nashville is at the vanguard of waste oil heaters, says the company’s Scott Walker.
He said EnergyLogic heaters double the heat rise of most other waste oi burners. Heat output is 48 C above room temperature. With a burner flame of 815 C, it’s ideal for shops and barns. He said many waste oil heaters max out at 15 to 21 C heat rise over room temperature.
As an added bonus for Canadian farmers, waste oil heaters, furnaces or boilers don’t require carbon tax payments.
“We wanted our burners to be the easiest to use and easiest to maintain. We have little convenience things like a low-fuel cut-off so you don’t drain the oil tank. Because if you drain the reservoir, then you have to go to the trouble of re-priming to get the heater going again,” said Walker.
He said that after the initial investment of $9,500 to $21,300, a person virtually heats for free. However, before becoming too enthused about the concept of free heat, remember that “free” always comes with a price tag attached.
Owners need to have an adequate source of free waste oil. Without enough of this component, the free heat next winter may turn frigid by January. It is important to keep in mind that next year a neighbour down the road might be competing for the good supply enjoyed on the farm this season.
Once over the fuel volume hurdle, there’s a lot of new technology packed into the way EnergyLogic can use a variety of different energy sources. Walker said the heaters are capable of burning the widest range of waste oils of any heater on the market, anything from No. 2 to 90W, including all synthetics.
The AccuTemp preheater maximizes the efficiency and heat output of the waste oil. A Danfoss metering pump provides consistent fuel delivery, regardless of fuel type and without manual adjustment when switching from one source to another.
“Our technology allows this wide range of fuels. Other conventional heaters only burn oils from No. 5 to 50W.”
It’s essential that whatever the fuel type, it must enter the combustion chamber ready-to-burn. Fuel passes through a preheating process to bring it up to a temperature that approaches the flash point, which is especially necessary for heavier fuels like waste oil.
An on-board air compressor delivers just the right amount of clean, dry air to blend with fuel in the nozzle. The nozzle sprays pressurized waste oil as a fine mist, maximizing the surface area to make it available to burn hot in the chamber. The mist, along with a blower motor, pumps extra oxygen into the chamber, keeping the flame moving in the right direction. Continuous spark keeps everything cooking.
Too little air will starve the reaction and result in unburned fuel and dirty exhaust. So extra air is required for heavy fuels. However, if there’s so much air that it’s not all consumed in the combustion process, it will only cool the chamber.
EnergyLogic deals with this by throttling the intake of the blower with an air shutter that provides the right amount of air to match the fuel provided by the Danfoss metering pump.
Proper draft through a chimney flue is crucial to complete combustion. Draft helps mix the combustion ingredients together and evacuates the resulting exhaust to allow for a continuous, stable reaction. Too much draft allows heat to escape before it can be transferred to the building. Too little draft causes exhaust to build up, creating undesirable by-products.
To ensure they are creating the hottest possible flame, engineers developed a flame-retention head that is positioned just in front of the nozzle to fine tune the fire. This is the final control for blending ingredients and maintaining reaction temperature to guarantee a complete burn plus minimize exhaust and heat loss.
To cope with the relatively higher temperatures compared to other heaters, the burn chamber is built out of stainless steel. Stainless is a superior heat conductor, is lighter and more resistant to warping and weld breakage. As well, it does a better job of incinerating contaminants that lead to corrosion.
Many waste oil heaters use compressed air to promote a more complete burn. However, they tap into the shop’s system 24/7 to provide that air, including off hours. The burners have an integral compressor that provides the correct amount of airflow with no manual adjustments.
All systems require a dedicated waste oil tank to stop water and solids from settling in the tank. Waste oil in the system is filtered through a set of fine steel screens and pumped to the heater with a volume metering pump, rather than a pump that relies on high fuel pressure. This allows the fuel to be delivered at a precise volume regardless of weight, temperature or viscosity. The right amount of fuel enters the combustion process at all times.
“We have a spin-on filter. It’s a modified hydraulic strainer. It goes up to 140 microns, so that prevents any plugging,” he said.
“With some conventional systems on the market, they recommend you adjust the air and oil up to four times a day. The higher temperature does a better job of burning all the fuel that we feed into the chamber.
“We found three main benefits. We go longer between maintenance intervals. We burn higher flash point fuels like synthetics and 90 weight oils. That stainless steel heat exchanger gives us the ability to hit that higher outlet temperature.”