Canadian Biomass Magazine

Residential use of wood pellets: a missed opportunity in Canada

February 10, 2021
By Gordon Murray and Harry (Dutch) Dresser

Boilers certified to EU standards come in many sizes and shapes. This one is a condensing boiler with an efficiency of about 94 per cent using the higher heating value of fuel. Photo credit: OkoFEN.

Canada is the second largest producer of wood pellets in the world – we support global efforts to tackle climate change and provide clean and responsible energy and heat for industrial, commercial and residential uses. Which begs the question, why aren’t we doing the same in Canada instead of exporting almost all of our annual production of three million tonnes of wood pellets to Europe and Asia?

The answer lies in large part to barriers that restrict the sale of boiler systems that use pellets into the Canadian market. It’s a catch-22: we don’t make the boilers in Canada and we can’t import them as they are manufactured, so the only market for our pellets lay offshore, to be used in homes and businesses around the world as a sustainable source of renewable energy and heat.

The problem lies in a little section of the Canadian Standards Associations requirements of CSA B51:

“Manufacturers in countries other than Canada that manufacture and export boilers and pressure vessels to Canada shall ensure that all boilers and pressure vessels are stamped with the appropriate ASME Code product certification mark and registered with the National Board.”


We believe that we should be using more of our wood pellets in Canadian homes. We could reduce reliance on expensive heating oil, lower heating costs for Canadians in rural and Atlantic Canada, reduce greenhouse gas emissions, and create hundreds of Canadian jobs. The solution is simple: install modern biomass heating systems in Canadian homes.

While none of these systems are made in Canada, we first need to be able to import these boilers from Europe where they must meet rigorous EU safety standards. Canada is, after all, a trading nation. We export the goods we excel at making and we import the goods we need. Why should biomass boilers be an exception?

Two-and-a-half years ago, the Wood Pellet Association of Canada (WPAC) initiated a project to reduce barriers to importing small biomass boilers manufactured in the EU, particularly pellet boilers. Despite our best efforts, we remain stymied by standards that haven’t evolved with global safety and market developments.

Pellets for residential heat continue to gain market share and popularity in western Europe, especially in Austria and Germany, where the boiler systems are also produced. To ensure public safety, these small pellet boilers are manufactured according to the EN 303-5 boiler safety standard (biomass boilers up to 500kW output power) as well as relevant provisions of European pressure equipment directives and machinery directives. These standards are safe, effective, and are recognized in most countries, with one notable exception – Canada.

Canadian authorities require boilers to be manufactured according to the Canadian Standards Association’s CSA B51 boiler, pressure vessel, and pressure piping code. B51 references ASME’s (American Society of Mechanical Engineers) boiler and pressure vessel code. CSA B51 and ASME, while safe, are incompatible with European-manufactured boilers.

The European requirements for the design and manufacture of the pressure vessels found in these small biomass boilers are based on hazard assessments and are substantially different from those found in ASME code. Hence, in order to sell these boilers in Canada, the pressure vessels must be redesigned to ASME specifications and manufactured using ASME-specified materials in ASME-certified factories.

Beyond the costs associated with redesign and manufacture, this accommodation increases the weight of the pressure vessel and approximately doubles the manufacturing cost, a detriment to the buyer. Given the small size of a developing marketplace in Canada, compliance with such requirements is unlikely to be rewarded. Therefore, the availability of these products for Canadians is limited to a few models of premium brands at premium prices or uncertified products marketed to be installed as non-pressurized systems. Such installations greatly shorten the boilers’ useful lives.

To eliminate this trade barrier, WPAC has asked the CSA B51 technical committee on boilers to change the standards to allow small biomass boilers certified to EN 303-5 to meet the pressure vessel standards. If other design considerations are met, the boilers would qualify to apply for Canadian Registration Numbers. The process of gaining consideration of this request has been slow, but it now lies in a critical phase.

While working with CSA, WPAC has also been working with the European Commission, European business associations and Canadian agencies interested in CETA compliance and the standards communities’ approach to co-operative consideration of trading partners’ means of assuring public safety. Notably, WPAC has met on several occasions with Provincial Territorial Advisory Committee (PTAC) representatives and is again invited to the Canada-European Union (EU) Comprehensive Economic and Trade Agreement (CETA) Regulatory Cooperation Forum (RCF) in February.

Our strategy is to educate, advocate and co-operate within the standards community and the economic and regulatory communities. To that end, Henrik Perssons, a senior test engineer at the Research Institutes of Sweden (RISE) and a member of the TC/57 Technical Committee, has prepared a presentation explaining the legal and regulatory underpinnings of the EU New Approach standards and their relationship to EN 303-5. The TC/57 Technical Committee oversees EN 303-5 and many other heating appliance standards. This presentation will be delivered first to PTAC members and their invitees soon. The presentation will be made available to the CSA B51 TC as well and to any other individuals or groups who are interested in the content and the change request.

A working group of a CSA B51 TSC created a substantial list of questions based on a comparison of ASME Section IV codes and EN 303-5 standards. That list was forwarded to CEN, the European Committee for Standardization, for its responses and to open communication between CSA and CEN. Work is underway in Europe to provide expert answers to the technical questions raised.

We can anticipate some of the early questions that might arise in this discussion from conversations we have had with boiler inspectors over the last three years. One of these questions may centre on the manner in which production certification occurs in the EU.

Manufacturers designing, fabricating and marketing products to CEN standards declare, on their own, that their products meet all applicable standards and directive requirements. No third-party confirmation is required for placement of the CE mark. Market surveillance is practiced to confirm compliance where questions arise. Both the self-declaration and market surveillance aspects of that practice could be challenging for Canadian regulators. These regulators are accustomed to prescriptive standards and well-documented compliance with those standards. Recognized third-party confirmation of manufacturers’ compliance with applicable standards could easily overcome that concern.

The maximum pressure a vessel can withstand can be derived a number of ways. Once derived, some fraction of that maximum pressure is considered its maximum allowable working pressure. This factor is variously called the safety factor, the design factor, or the design margin. ASME and EN 303-5 have different design margins with the ASME margin more conservative than the EN 303-5 margin. The ASME design margin for the sorts of boilers under discussion here is 3.4; that means that the designed vessel must be capable of withstanding 3.4 times the maximum allowable working pressure (MAWP) without leaks or permanent deformation. The type test for EN 303-5 pressure vessels for the same boilers requires a design margin of two. The vessel must be capable of withstanding pressure twice as great as those allowed for operation. Both sets of standards require pressure relief valves to help ensure pressure vessels are never subjected to pressures much beyond MAWP.

While these standards result in pressure vessels of different weight, both of these design margins have demonstrably protected the public safety. Neither ASME nor EN 303-5 boiler pressure vessels are prone to failure.

Today, standards that encourage innovation have led us to drive automobiles that are safer and have smaller, more efficient engines, resulting in cleaner, more economical performance. Such standards are resulting in ever smaller and more efficient pellet boilers in western Europe with year-over-year growth in sales at more than 40 per cent this year alone as the focus on environmental care sharpens.

WPAC would like to see Canada participate in this booming industry through the use, importation and manufacture of finely crafted pellet central heating systems manufactured to proven EU standards. We’d also like to see Canadians be able to benefit from its surrounding forests by utilizing the clean, renewable energy provided by Canadian pellets.

Harry “Dutch” Dresser, Ed.D., is a biomass heating expert. Gordon Murray is the executive director of the Wood Pellet Association of Canada

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