By Simon Blake
New energy efficiency requirements being considered for both residential and commercial storage type gas and oil water heaters set to come into effect Jan. 1, 2020 will increase costs as condensing technology becomes the industry standard in new construction.
Hot water heating accounts for 18 percent of energy use in homes and eight percent in commercial buildings, reports Natural Resources Canada (NRCan). As a result, it has become a major target in the battle to improve energy use and reduce carbon emissions from fossil fuel powered appliances.
Commercial water heaters have not previously been included in energy efficiency regulations. That will change if current proposals under Amendment 15 to the Canadian Energy Efficiency Regulations take effect in 2020.
“We are just introducing commercial water heating into our regulations. We are trying to follow the U.S. scopes as best we can because the market is integrated,” said Rosalyn Cochrane, NRCan team leader for HVAC/R standards development.
To harmonize with the U.S., Canada will adopt uniform energy factor (UEF) efficiency measurement for residential duty commercial water heaters, which is designed to provide a more accurate “apples to apples” method of comparing efficiencies by dividing water heaters into different categories so that they can be better compared with like equipment.
Residential water heaters
NRCan is proposing that all tankless water heaters – residential and commercial – be condensing for both new construction and retrofit, achieving a UEF of 0.87, which is equivalent to 0.90 energy factor (EF). “There is no proposal for condensing technology in residential storage water heaters,” Cochrane noted.
Energy factor is a measure of the amount of hot water produced per unit of fuel consumed over a typical day, accounting for standby losses and equipment efficiency.
Currently, a typical storage tank gas DHW heater has an EF of 0.60 to 0.68. Condensing power vent models are already achieving more than 0.80 EF, remarked David McPherson, general manager for Rheem Canada, Brampton, Ont. Some tankless models are achieving up to 0.96 EF, he added.
Condensing gas storage tank models are roughly double the price versus a conventional unit, remarked Paul McDonald, general manager at Bradford White Canada in Halton Hills (Milton), Ont. As well, with condensing equipment, acidic flue gases may require more expensive venting materials.
Some builders are already installing condensing water heaters to gain energy efficiency credits under regulations like Ontario’s SB-12 Energy Efficiency for Housing compliance path – and to be able to market their products as “green” homes.
Heat pump water heaters have been slow to catch on in Canada, primarily due to cost. However, some builders are installing them, again, where they can achieve energy efficiency credits for doing so.
Technologies are changing rapidly, remarked McPherson. Increasingly, homeowners are looking for connected technologies plugged into the internet. In addition to allowing homeowners more control over their appliances, they also reduce energy use.
On the commercial side
Under Amendment 15 to Canada’s Energy Efficiency Regulations, equipment used in new commercial construction will need to be condensing, while that used in retrofit will be near condensing. The proposal for retrofit will be 82 percent thermal efficiency plus a maximum standby loss component, said Cochrane.
“The move to condensing commercial water heaters in new construction has already begun, with cost reduction in fuel a major driver,” noted McPherson.
There are three basic categories of commercial gas and oil water heaters.
- Residential duty commercial (RDC) units for small commercial and large homes
- The typical commercial storage tank water heater and the
- Instantaneous commercial water heater
(Full details of the proposed changes can be found at www.nrcan.gc.ca/energy/regulations-codes-standards/19835)
“For commercial electric water heaters, the intention is to harmonize with standards in the U.S.,” added Cochrane.
“If it’s a new building at least somebody can consider the vent ramifications at the very beginning,” noted Tom Gervais, B.Eng., director of specifications and product development for Bradford White Canada. “The equipment and the venting will be substantially more expensive, but that will be factored in to the cost of construction.
Likewise, the building can be designed to accommodate the shorter venting runs of condensing equipment – typically about 100 feet before mechanical draft boosters are required.
“This can be a challenge on the retrofit side, where the mechanical room, size and location is designed for traditional tank type solutions,” remarked McPherson. “Conversion costs will be high for condensing, and in some cases just not viable.”
There is some confusion as to where boilers that are used to generate DHW fall under proposed new energy efficiency requirements for boilers and water heaters.
Bradford-White refers to them as ‘volume water heaters.’ “NRCan tends to refer to them as instantaneous commercial water heaters, which causes some confusion,” said Gervais.
Regardless, proposed efficiency regulations for these units are causing concern. “A boiler water heater – a fin-tube boiler connected to a storage tank – is going to have to be condensing,” said Gervais. “It will be a challenge because there is also a change to the test standard,” he added.
Previously, the CSA test standard did not consider vent categories. “Even though the efficiency standard might allow you to vent into a B-vent, the construction standard might eliminate the B-vent option.”
This can be a problem in a large hotel, for example, that might have two 1.5 million Btu/h water heaters connected to a 1,500-gallon storage tank. “Under the new rules, if you lose one of those heaters, any replacement is going to have to be fully condensing,” added Gervais. “That means it’s going to be very difficult to vent.”
He also worries that near condensing equipment will condense at times, which would also eliminate the B-vent option.
Venting options explored
However, NRCan has explored different venting scenarios, said Cochrane. “All the costs are looked at from the perspective of venting, installation costs, retail costs – all those costs are (factored) in.”
Working with a consultant, different building types have been modeled and analyzed. NRCan models venting based on flue gas temperatures. That determines the venting material. “We cost out and take into account – at 80 percent (thermal efficiency), at 84 percent at 86 percent – what the venting material is…
“Our assumption is that there would be no change to venting systems to go from the baseline efficiency in the marketplace to our proposed efficiency of 82 percent,” she added.
NRCan expects to pre-publish Amendment 15 in the Canada Gazette, Part 1, later in 2018. That will be followed by an official 75-day comment period. “What we’ve been doing up to this point is what we call pre-consultation,” noted Cochrane.
NRCan has conducted several webinars with associations and water heater manufacturers to get the word out and to receive feedback from the industry. It has received written comments from all manufacturers, the Canadian Institute of Plumbing and Heating (CIPH) and the Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI). Several changes have been made based on those comments.
“The U.S. has proposed efficiency regulations for commercial water heaters as well and, in some cases, those are significantly higher than what we are proposing. We’ve been working quite a bit with the industry and I think we’re to the point where we’ve got a solid proposal that we will get support for,” said Cochrane.