Got Trees? An Outdoor Wood Furnace Will Cut Your Energy Bills Down To Size

If you live in a suburban or rural area near a source of cheap wood, you could heat your home for the entire season for the cost of one month’s electric heat bill. An outdoor furnace requires less tending, eliminates respiratory problems caused by burning wood indoors, and keeps the wood burning mess outside.

There are a surprising number of outdoor furnace manufacturers with a wide range of styles and designs to accommodate different heating capacities and fuel sources. Some of these furnaces have the capacity (500k Btu) for commercial applications.

Burns Best makes a corn or wood pellet version. Taylor Waterstoves has a multi-fuel model that burns coal or wood. Hardy Manufacturing makes an all stainless steel furnace with a built in hot water exchanger.

One of the selling points of an outdoor furnace is the convenience of locating it near the wood fuel source. Since the water heated by the furnace is pumped to your home through insulated, underground piping, the furnace can be set up as close as 2 feet, or as much as 500 feet from your house.

All outdoor furnaces are designed to work with any existing heating system and can be thermostatically controlled. If you have a forced air system, you can use the existing duct work but you will need to install a water-to-air heat exchanger in your furnace. Your furnace is still available as a back up.

If you already have radiant floor heating, you would connect the underground feed from the outdoor furnace to the existing circulating pump.

For radiant baseboard heat, you can connect the piping directly to an existing boiler or install a water-to-water heat exchanger. By adding the water-to-water exchanger, you receive the added benefit of free hot water while the existing furnace functions as back up.

An outdoor boiler can even be used to heat your swimming pool, driveway, work shop, greenhouse, or multiple buildings.

The firebox designs vary from manufacturer to manufacturer, but all are constructed from stainless or carbon steel. Although each manufacturer claims to be using a grade of stainless steel superior to the competition, they all agree that heat transfer efficiency is almost 3 times better with 16 gauge stainless steel than with 3/8" carbon steel. An all stainless steel firebox also resists rusting and burnout that occur in standard carbon steel.

Some fire boxes are large enough to accommodate a 30” diameter by 72” log. The problem I would have is getting a log that size into the firebox. Normally, outdoor furnaces are loaded twice a day. Burn times per load vary from 12 to 96 hours depending on what you’re heating, the outside temperature and how well your house is insulated.

One trait all outdoor furnaces have in common is versatility. What ever your heating needs are or the type of fuel you burn, it’s possible to design a system for any heating scheme you can imagine.

Alternative-Heating-Info.com offers a unique look into geothermal heating and cooling, radiant heating, solar heating systems and pellet burning stoves

Faulty Furnace Exhaust Vents... The Rest Of The Story

 

Early in 1995 the Ministry of Consumer and Commercial Relations (MCCR) announced a program to replace up to 20,000 mid-efficiency gas furnaces in Ontario, because their plastic vent pipes were prone to failure, and might leak carbon monoxide into the house. Other sources indicated the number might have been as high as 40,000 - but no one knows for sure.

The crux of the problem was that no other type of vent pipe had been approved for use with mid-efficiency furnaces.

Hundreds of home owners planned to sue the government, the manufacturers and others for refusing to pay for the entire replacement. At that point, home owners were expected to pay about $1000 of the estimated $1500 cost to exchange the furnaces for high-efficiency models, which would function safely with plastic vent pipes currently available. The home builder was to pay $200, the ONHWP $200, and the gas companies $100.

By the end of 1995 neither the Government of Ontario, which approved the faulty vent pipes, nor the manufacturers had made any contribution toward the cost of replacements in private homes and businesses. But the government did pay for replacements in government-funded non-profit and co-op housing.

And apparently, the program offered nothing to people who had already replaced their mid-efficiency furnaces before this program was announced.

On September 12, 1995, the Ministry of Consumer and Commercial Relations issued a Safety Order requiring all owners of heating appliances with high-temperature plastic vents to have these systems corrected by August 31, 1996. Gas utilities and propane suppliers were required by Ontario law to discontinue the supply of fuel to appliances which had not been corrected by the deadline. Correction consisted of replacing the defective vent with an approved alternate vent, if available, or replacing the whole heating system.

Two vent pipe manufacturers in Toronto claimed they had safe, effective replacement vent pipes (a special grade of corrosion-resistant stainless steel) which would solve the problem with mid-efficiency installations. These replacement pipes had not yet received approval, and for some furnaces, replacements were never approved. One manufacturer asked the Premier’s office to spend some of the millions ear-marked for furnaces in government-funded homes, to speed up testing and approval of the replacement pipes. The upgraded vent pipe installations typically cost a little over $400 per house.

In theory at least, all affected furnaces should have been re-fitted or replaced, by August 31, 1996.

However private home inspectors were finding some of these heating systems still in service, with the original hi-temp plastic vent pipes still in place, as late as the summer of 1997. It is entirely possible that some still exist today. Home owners should watch out for plastic exhaust vent pipes labelled Sel-Vent, PlexVent or Ultravent. (or any vent other than those in service on high efficiency furnaces, which are labelled ABS, PVC or CPVC, and are acceptable)

A licensed gas-fitter/installer should be consulted, if own a mid-efficiency furnace and you are uncertain of the vent pipes attached to it.

All owners of gas heating appliances should have CO (carbon monoxide) detectors in service, and have their appliances inspected regularly.

Gil Strachan is a professional home inspector, representing Electrospec Home Inspection Services in east-central Ontario, Canada since 1994. Visit http://www.allaroundthehouse.com to learn more about home inspections.

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