User-friendly waste-oil-fired heaters

While old-time waste-oil space heaters were a pain to maintain, fleet managers are warming up to new models that provide free (and trouble-free) heat for the shop.

By Rich Cross, Senior Technical Editor

Once upon a time, waste oil heaters were primitive, maintenance-hungry beasts that dripped oil into a hot, cast iron pan where it was vaporized and ignited to keep mechanics toasty. Because these "pot burners" tended to require an excessive amount of tender loving care, they got a very cool reception from labor-cost-conscious fleetmen.

For one thing, rock-hard gunk had to be chipped out of the burner pan on a daily basis in preparation for manual lighting; a tedious chore that could take about 15 minutes. And igniting one of these units could provide an explosive adventure worthy of Indiana Jones, because most makes/models lacked a safety switch that'd kill the pump when the pan already was awash with fuel.

Without that safeguard, heaters could "flash back" in a rather spectacular fashion when started, causing traumatic eyebrow incineration or worse.

Further, vaporizing-type heaters provided less than optimum climate control since they ran constantly and only offered a "high" and "low" setting. Consequently, lacking blizzard conditions, operating a hefty heater on "low" eventually could turn a small shop into an oven, requiring temporary shutdown.

Finally, since thick and thin waste oils tend to stack themselves into well-defined layers, tinkering with a pot burner's flow rate also was needed; unless, that is, you wanted to communicate with neighboring tribes by sending dense, blue smoke signals from the roof of the shop. Admittedly, however, feeding one's heater a steady diet of diesel drain oil virtually eliminates the need to tweak a pump's delivery rate; until, perhaps, Old Man Winter thickens the contents of an outdoor waste-oil tank.

Today, most folks are opting for the vastly improved, extremely-user-friendly, atomizing type heaters that dominate the market. In fact, these newfangled space heaters are showing up in a steadily increasing number of shops across the country.

Using waste oil to warm a shop makes a lot of sense, monetarily and in terms of environmental liability. For one thing, you no longer have to pay someone to pick up your oil. And you have zero "cradle-to-grave" responsibility for disposing of the oil because it's recycled on site. Moreover, management can afford to keep mechanics warmer—and, perhaps, happier and more productive—because there's no budgetary constraint on heating a facility with free fuel.

Functionally akin to home furnaces, atomizing heaters preheat the oil, use air from the shop's compressor (Reznor models have built-in compressors) to provide a fine spray of fuel, and burn much more efficiently, therefore cleaner, than their pot-burner predecessors.

On the average, heaters producing less than 250,000 Btu/hr have an installed price of around $3,000 to $5,000. And their bigger brothers, rated up to 500,000 Btu/hr, typically cost about $5,000 to $10,000.

Realistically, no minimum volume of oil needs to be generated to justify the purchase of such a heater because waste oils always can be supplemented by home heating oil. And buying a heater need not break the bank because many suppliers provide for a lease or lease-purchase.

Among their claims to fame, these new heaters are thermostatically controlled, light automatically, use squirrel cage blowers or prop-fans for air distribution, and basically run unattended. All atomizing heaters are omnivorous and thrive on a diversified diet where major food groups include crankcase oil, automatic transmission fluid and No. 2 heating oil. And manufacturers such Reznor use patented constant-pressure or constant-volume pumps that permit drinking oils of varying viscosity (typically, up to SAE 50) without manually adjusting the feed rate. One caveat: Some synthetic oils have a flashpoint exceeding 400º F and won't burn properly.

Adding to the appeal of today's heaters, their combustion chambers and heat exchangers can be cleaned painlessly by ascending a sturdy stepladder and using a shop vacuum to evacuate fluffy ash resembling talcum powder. "Maintenance is further simplified by models with a swing-out burner that provides quick access to the combustion chamber, nozzle and firing electrodes," says Glenn Musser, product manager for one manufacturer. While some models still employ a target wall (made of ceramic material, in some cases) within the combustion chamber that ultimately may burn through or otherwise require replacement, others do not.

As you might expect, the need for cleaning varies primarily by the amount of grunge and gunk in the oil being burned. Ideally, most heaters should be cleaned after about 500 hours of operation. So, putting an hour meter in the circuit is helpful.

Regulation is minimal
An EPA publication entitled Managing Used Oil: Advice For Small Businesses reports that recycling used oil by burning it for energy recovery "is good for the environment." And, currently, EPA doesn't require a maintenance manager to determine whether used oil destined for "direct burning" (i.e. without processing to remove contaminants) in his shop's space heaters is hazardous or non-hazardous, provided that three conditions are met:

1. The space heater only burns waste oils generated by his fleet and/or received directly from "household do-it-yourself used oil generators;"

2. The unit is designed not to generate more than 500,000 Btu/hr;

3. It's vented to the outside of the building.

With respect to storing used oil, EPA requires that relatively large, aboveground tanks be labeled "Used Oil," provide double containment (i.e. double-walled construction or an external wall/dike) plus overfill protection (including an alarm, automatic flow restrictor or shut-off) and provide for constant monitoring of product transfers. Labeling also is required on 55-gal drums, other containers, and the fill pipes of underground tanks containing used oil.

For more information on matters related to used oil, solid waste, hazardous waste and underground storage tanks, call EPA's RCRA hotline at 800-424-9346 or 703-412-9810; fax 703-412-3333; write to "RCRA Information Center, U.S. EPA (5305W), Washington, DC 20460."

Keep in mind that state and local restrictions/regulations on used oil storage and the use of waste oil heaters can be far more restrictive than Uncle Sam's. For example, burning used motor oil is strictly prohibited in environmentally paranoid California while New York City generically bans the use of "space heaters" and New Jersey (which also used to ban such heaters) now smiles upon their use but requires registration.

Inquisitive persons with access to the World Wide Web can read about new and proposed used-oil-related regulations by clicking on the Used Oil Management Program portion of the Web site operated by the Environmental Protection Agency.

And hot links to state environmental agency Web sites can be found on the Web site operated by the American Petroleum Institute.

While scholarly pursuit of more information is always a good idea, fleetmen should be able to depend on their local heater distributors to ensure compliance with state/local environmental regulations plus fire and building codes; which, in most instances, reflect varying interpretations and adaptations of national codes (such as NAFTA and BOCA) and U.S. EPA requirements.

Excerpted from the article which appeared in the September, 1999 issue of CCJ. © Copyright 1999 All rights reserved. Cahners Business Information, Commercial Carrier Journal

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