TESTING CREOSOTE-REDUCING DEVICES: THE RESULTS

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

By Day 8, the fires in both the Smoke Consumer-equipped units had become difficult to sustain at a level comparable to the other stoves. The filters were clearly somewhat clogged. We made two attempts to clean them with hot fires on Day 8 (the other stoves were also operated to achieve similar hot fires), but despite the high temperatures achieved, the filters remained dirty. (It may be that once the clogging has passed a critical point, it becomes more difficult to achieve the required conditions for burning off the deposits, and that the necessary temperature may be higher than 450°F. )

We then scraped off the brownish black residue clinging to the leading edges of the filters and tapped the reactor plates to knock out loosened particles. (Manual cleaning every eight days is within the manufacturer's guidelines, particularly since our "days" involved about 12, not 24, hours of burning.) After this mechanical cleaning, the drafts were markedly improved. (In retrospect, if we had relied less on the continuous-burn reactor cycle and more on mechanical cleaning, the Smoke Consumer's performance might have been somewhat better.)

CONCLUSIONS

For the reasons set forth in the accompanying boxed discussion of chimney systems, we believe that the last column of our table contains the most meaningful test results. As you can see, all the devices did reduce creosote buildup: the barometric draft control by 75% . . . the Smoke Dragon, 45% .. . . . and the Smoke Consumer, 23%r. In normal household use, of course, the effectiveness figures can vary.

A barometric draft control can, then, reduce creosote substantially. And unlike the other two devices tested, its effectiveness is dependent on neither a minimum average smoke temperature nor occasional high-temperature burns to remove deposits. The regulator also (as its name indicates) controls draft. This function results in a stabilized heat output and a reduced danger of the appliance's being overfired. Stack temperatures are substantially cooler, too, a factor which can be very valuable if the chimney is of questionable safety. Furthermore, the barometric draft control is the least expensive of the three devices tested.

There are, however, potential liabilities as well. Even though draft regulators can reduce the likelihood of a chimney fire by limiting creosote accumulation, the air added by such a device if a blaze were to occur might make the chimney fire more intense. (The best way to control a chimney fire is to limit its air supply as much as possible.) And the loss of room air up the chimney is another liability . . . although its net effect on a house's heat loss is probably small.

The Smoke Dragon was also effective in reducing creosote buildup. In addition, it has the advantages of generating extra heat and reducing total emissions. Like both other devices we tested, however, the Smoke Dragon does reduce the draft to some extent, and hence will not prove satisfactory on systems with only marginal draft (or, for that matter, on fireplace stoves operated with open doors). Furthermore, the Smoke Dragon is the most expensive of the three, and requires electric power to operate. Finally, some people might be annoyed by the noise of the blower, which is considerable at high speed. . . but less noticeable when adjusted at the low setting.

RSS | Comments | E-mail | Print