Manufacturers expect heater prices to climb by 50 to 60 per cent
Nelle Maxey
Sun
Every year American homeowners cause at least 2,000 residential fires by storing or spilling flammable liquids – gasoline — around gas-fired appliances.
One result is a new North-American-wide safety standard for hot-water heaters, a standard some in the industry are calling the biggest change in product design since modern water heating was invented more than a century ago. And all in the industry expect it will result in higher heater prices.
How much higher? Most manufactures are talking about a cost increase of 50 to 60 per cent, depending on “which level of the distribution chain you are in.”
Some manufacturers have also adopted order-limit policies to distributors to restrict inventory build-ups of old equipment before the the new standard becomes ”the law of the land.” (In Canada phase 1 of the FVIR, for flammable vapour ignition resistance, standard comes into effect on July 1.)
Because gas-fired water heaters draw combustion air through vents at the bottom of the appliance, flammable vapours — which are heavier than air and naturally sink to floor level – can be drawn into appliance resulting in a fire or explosion.
In response to this safety problem, the American National Standards Institute has developed a new standard and a manufacturer’s consortium has developed the necessary technical adaptations for the equipment. The new standard requires that gas-fired hot water heaters be designed so they “shall not ignite flammable vapours outside the water heater.”
Basically, the design change developed by the consortium involves a sealed combustion chamber with an air inlet that directs airflow through a perforated arrestor plate. If flammable vapours enter the combustion chamber, the flames burn off the top of the arrestor plate and are prevented from flashing back into the room.
However, the arrestor plate created its own safety problem.
”If the arrestor plate becomes blocked with contaminants, the unit may not combust properly,” one manufacturer’s representative reports. ”Once the water heater starts reburning the same air, it produces carbon monoxide.”
PM Engineer magazine, in surveying manufacturers about the new standard, found they have developed at least three solutions to LDO contaminations, or contamination by lint, dust and oil. Some employ baffles or louvres to change direction of intake airflow and thus cause LDO particulates to drop out of the air stream.
One manufacturer has a removable screen at the bottom of the water heater for filtering LDO. Another has positioned the air intake on the sides
of the tank rather than at the base. This cuts down on the pickup of LDO contaminates which accumulate at floor level.
The same survey also found manufacturers are installing temperature sensors that shut off gas flow when triggered by excessive internal temperatures whether in response to vapour ignition or a clogged arrestor plate. The sensor used by Rheem Manufacturing Co. is unique in that it shuts off air flow and gas flow to stop combustion in the chamber and avoid overheating the unit in an uncontrolled burn.
As much as the new standard is needed, its introduction does mean homeowners will be paying more for an appliance at the same time they are paying more for fuel.
Industry has predicted that the privatization and deregulation of BC Hydro will mean an increase in electric energy costs of between 50 and 60 per cent over the next few years.
As for gas rates, the British Columbia Utilities Commission last year approved a 16-per-cent increase in the price of gas. Terason said last year it expects the new price would add $184 annually to a typical Lower Mainland homeowner’s gas bill; $167 to an Interior homeowner’s bill and $183 to a Kootenay homeowner bill.
To keep gas competitive with electricity, however, the increase reflected only a portion of increased commodity cost gas utilities are paying for natural gas in the current North American market.
This means gas utilities will have shortfalls to recover in future rate increases. When electric rates start to climb, you can expect gas rates to climb as well.
Web sites for readers wanting to know more:
www.ansi.org
www.appliancemagazine.com
www.bradfordwhite.com
www.oee.nrcan.gc.ca
www.pmengineer.com
www.reevesjournal.com, Spring 2003
© The Vancouver Sun 2004