Say hello to the Hitachi series Canada’s newest name in high-performance heat pumps.
NOW EXCLUSIVELY AVAILABLE AT MASTER airHome systems are designed for all-season comfort with the smart features your customers want and the reliability you need.
•
•
•
Start at master.ca/hitachi or talk to your Master rep today.
Backed by industry leading technology, The HPX™ Air-to-Water Heat Pump is the perfect solution to year round comfort. Pair it with the SKy-35 control to optimize your comfort, operating costs and energy consumption.
During warm weather installations remember to consider the defrost issues of residential heat pumps when it comes to positioning and commissioning.
By Ian McTeer
Net Zero in Nunavut
Using an air-to-water heat pump system for a low-temp heating solution in Canada’s north.
By Doug Picklyk
EDITOR
DIGITAL EDITOR
ASSOCIATE PUBLISHER
NATIONAL ACCOUNTS
ACCOUNT COORDINATOR
MEDIA DESIGNER
CIRCULATION MANAGER
PUBLISHER
CEO
Doug Picklyk (416) 510-5218 DPicklyk@hpacmag.com
Jack Burton (416) 510-6809 jburton@hpacmag.com
David Skene (416) 510-6884 DSkene@hpacmag.com
Amanda McCracken (647) 628-3610 amccracken@hpacmag.com
Kim Rossiter (416) 510-6794 KRossiter@hpacmag.com
Emily Sun esun@annexbusinessmedia.com
Urszula Grzyb (416) 442-5600, ext. 3537 ugrzyb@annexbusinessmedia.com
Peter Leonard (416) 510-6847 PLeonard@hpacmag.com
Scott Jamieson
Living with a Cold Climate Heat Pump
Despite challenges that may occur with future electrical demand, today’s heat pump technology is up to the task for this Canadian homeowner.
By Ian McTeer
Carmichael Engineering’s new branch office in Belleville provides a template for future projects.
By Doug Picklyk
During warm weather installations, remember to consider the defrost issues of residential heat pumps when it comes to positioning and commissioning. BY
IAN McTEER
We may be into the cooling season right now, but it’s never a bad time to remember the cold weather will be returning, so when installing a new heat pump unit we need to consider that even the most advanced cold climate air source heat pump systems encounter operational challenges with defrosting issues emerging as a persistent concern.
From poor installation practices that lead to inefficient operation to improper commissioning that undermines performance, the root of these problems often lies in oversight during sales and specification processes.
When heat pumps are installed in suboptimal locations, or commissioned without regard for manufacturer’s in -
structions and industry standards, defrosting becomes a recurring obstacle, diminishing both efficiency and comfort for homeowners.
In this article, I will explore some intricacies of defrosting minutia that too often lead to poor performance or even catastrophic failure of residential cold climate air source heat pumps (ccASHP).
The only way a heat pump can capture heat energy from the outdoor air is to engineer an evaporator coil that runs much colder than the outdoor air entering that coil. Depending on the dewpoint temperature of the entering air, the outdoor evaporator coil will reach its frost point when the sensible air temperature
entering is approximately 47F (8.3C).
The AHRI 210/240-2023 standard uses 47F as the first rating point for heat pump heating capacity. This rating point was adopted early on and likely because heat pumps were typically used in moderate climates in the U.S. where the outdoor temperature rarely drops below freezing.
Thus, 47F is a common average winter temperature in many of these geographies. Therefore, it provides a realistic and relevant benchmark for comparing the performance of different heat pump models.
For example, when an outdoor coil is engineered to have a 15F-degree delta T between the coil air entering temperaContinued on p6
Maximize energy savings for every customer with heat pump technology.
4x MORE efficient*
Electronic display and built-in Wi-Fi controls to set modes and review diagnostics. Smaller minimum space required (450 ft3) without added ventilation.
Whisper quiet operation at only 45 dBA.
*Compared
Interactive Control: Touchscreen LCD display to select modes, view run information, get troubleshooting alerts, and more.
*Compared to a
Quick Installation: Integrated design and pre-charged refrigeration system make for a quick and easy install.
High Performance: First-hour delivery exceeds 150 GPH and heat pump power rating of 3.15 HP.
Durable Design: Glass-coasted tank. Electric elements that feature incoloy sheathing for protection from oxidation and scaling.
ture and the saturated temperature of the refrigerant within the coil, that means when the saturated temperature of the refrigerant is at 32F (0C), the outdoor air entering the coil will be at 47F (8.3C), thus the potential requirement for defrost cycles begins. But that’s not all, the number and duration of defrost cycles are related to the ambient outdoor frost point.
Allow me to illustrate. In late January of this year, an all too often episode of freezing rain befell the Southeastern Ontario region where I live.
The storm delivered freezing rain and later several inches of heavy wet snow over a two-day period. The air temperature entering the outdoor coil was approximately 34F (1.1C), dew point temperature of 31F (-0.6C) [data provided by the weather office] and strong winds out of the South gusting to 40 mph (64 km/h).
When the outdoor dew point temperature is that close to the outdoor ambient temperature, more defrost cycles will be required. This is not a great air source heat pump day.
Even though my own heat pump outdoor unit is partially shielded by a group of evergreen cedar shrubs, some snow managed to accumulate in front of the fans (see Figure 1).
Eventually, the outdoor temperature dropped to 28F (-2.2C), the wind shifted to WSW gusting to 5 mph (9 km/h) and the dew point temperature dropped to 16F (-9C) as the drier air moved in.
While my current data collection setup does not permit me to view accumulated defrost cycle time periods, we can look at the heat pump thermostat data collection I used in another application (see Figure 2).
In the column marked “Last Month” this two-stage heat pump ran 408 cycles in Stage 1 (Y1) heating and 44 cycles in Stage 2 (Y2) heating for at total accumulated time of 11,737 minutes
(196 hours).
The unit ran 29 defrost cycles accumulating 153 minutes in defrost, or approximately 5.3 minutes per defrost cycle. Is that good?
The answer is the shortest possible complete defrost cycle is the best defrost cycle.
Notice in the “Today” column, there is one defrost cycle lasting 6 minutes, also notice both W1 and W2 gas heat cycled to temper the cold air produced by a heat pump operating in cooling mode during defrost.
Thus, “Last Month,” regardless of
temperature and dew point conditions, this heat pump was in defrost only 1.3% of the time. Defrosting averaged 5 to 6 minutes per cycle, this is close to ideal — ideal being zero minutes in defrost, something only a ground source heat pump can achieve.
Moisture frozen onto the fins of the outdoor coil becomes a problem when it accumulates to the point where air flow across the coil is significantly diminished and effective heat transfer is then substantially reduced.
Traditionally, by way of a reversing valve installed in the refrigeration circuit, hot gas is rerouted through the outdoor coil heating it to a point where the accumulated frost or ice will melt away. Once defrosting is completed, the refrigeration circuit resumes its heating mode by directing the hot gas to the indoor coil where space heating of the building continues.
Defrosting is an inherent inefficiency. During each defrost cycle, heat is literally “stolen” from the indoor space by shifting the reversing valve into cooling mode (hot gas goes outside) and using that heat to melt frost/ice from the outdoor coil.
In a forced warm air system, backup heat will be energized to temper the cold air being delivered to the space by the heat pump. When the indoor heat source is upstream of the indoor coil, additional heat from that source is added to the refrigerant helping to defrost the outdoor coil more quickly.
Most often, during defrost, the indoor heat source operates at 100% capacity and is not thermostatically controlled. Thus, we want the shortest defrost period combined with the driest possible outdoor air to provide the best air source heat pump efficiency. Since we can’t control the moisture content of
Designed for pro ease-of-use and profitability. FocusPRO helps reduce job complexities and time on-site while supporting recurring business thanks to its broad system compatibility, UWP® wall plate, snap-on private label, and competitive price.
Provide your customers with the best quality thermostat with your label attached through the Private Label Program.
Personalize up to three full lines of information printed onto the thermostat’s snap-on accent piece.
the outdoor air, what can be done to ensure efficient defrosting?
Always follow manufacturer’s location, clearance and wind shielding instructions.
The answer is: just about everything!
Wind baffle is needed on a roof top location…always windy!
Despite a weather protected top design, water dripping from damaged overhead eavestrough created ice blockage over the heat pump air discharge outlet.
In defrost, a considerable amount of water is produced. The concrete slab should be slightly tipped forward to encourage drainage away from the building.
This unit is icebound. Possible causes: loss of refrigerant critical charge, exposure to winds, recirculation from discharge to inlet…no amount of defrost will clean this coil. Manual defrost using buckets of hot water will be necessary.
Defrosting is more than just a control board in the outdoor unit. Steps can be taken for defrost optimization:
an acceptable wind
or drip shield!
Patio slabs can be undermined causing a shift and potential refrigerant leak. The horizontal discharge unit is also too close to the wall.
This unit is shut down in a below balance point situation…too cold outside and the backup unit has taken over. A snowstorm occurred in the meantime, loading the condenser fan with snow and possibly ice. Unless cleared manually, or luckily melts away, the fan may be locked-up or out of balance causing damage to the motor/fan as the unit restarts.
the outdoor air, what can be done to ensure efficient defrosting?
The answer: “Just about everything!” Defrosting is more than just a control board in the outdoor unit. Steps can be taken for defrost optimization:
• Start by ensuring the heat pump equipment is properly specified: use AHRI matched components.
• Can the distribution system handle the necessary airflow – it’s possible a back-up gas furnace will require more airflow than the heat pump.
• Specify top quality air filters, MERV 11 is a good benchmark.
• Measure line set carefully following manufacturer’s guidelines for tube sizing, run and rise.
• Be sure to commission the unit following the manufacturer’s instructions: deep vacuum and charging in cooling mode could be the best practice in most cases.
• Use manufacturer supplied tables to verify the system is correctly charged.
• Pay attention to the location of the outdoor unit; it should be on a solid base, out of the prevailing wind, protected from dripping water.
Two defrost strategies are commonly used with today’s heat pumps: time and temperature initiation; or demand initiation.
Time and temperature (T/T) initiation defrost control works well with units installed in milder winter climates and should not be used in cold climates, AHRI Region V, in my opinion.
The T/T system consists of an electronic control board that monitors a normally open coil temperature thermostat clamped to an outdoor coil tube stub-out near the bottom of the coil.
• While running the heat mode, if the coil thermostat detects a coil temperature below 30F (+/- 3F), the switch
Continued on p10
HEAT PUMPS | VENTILATION | DOMESTIC HOT WATER
THE MITSUBISHI ELECTRIC ADVANTAGE
u Quality And Reliability You Can Trust
u Efficient Products Designed For The Canadian Climate
u Over 35 Years Of Successful Installation
u Strong Canadian Customer Support Team
u Local Supply of Products
closes, signaling the control board conditions are right for defrost.
• The control de-energizes the outdoor fan motor, shifts the reversing valve to cooling mode and energizes backup strip heaters or a fossil fueled furnace indoors.
• Hot gas is now directed to the outdoor coil, and once the defrost thermostat detects the coil temperature has increased to approximately 65F (+/- 5F), defrost is terminated.
• The control board timing function monitors accumulated compressor run time: three timing options are permitted, 30, 60, or 90 minutes can be selected. For example, if the 60-minute timing alternative is employed, even though the defrost thermostat has been closed for 59 minutes of continuous or accumulated run time, the unit will not defrost until the 60th minute has passed.
• T/T control will terminate defrost after 10 minutes if the thermostat fails to reach termination temperature.
Two major problems with T/T defrost controls that can cause poor performance or high utility bill complaints: T/T defrost will often initiate defrost cycles when they are not needed, as T/T cannot deal with frosting caused by high humidity conditions; and for the opposite reason, the T/T control may hold-off defrost during rapid icing conditions because of the timing requirement.
Demand Defrost Control (DDC) has been dramatically improved over the decades since its introduction in the mid 1980’s. DDC is designed to permit defrost only when coil icing conditions have reached a point where heating performance becomes seriously reduced.
Many of today’s inverter driven cold climate heat pumps use demand defrost logic. Data is acquired from input provided by an ambient air temperature sensor. Additional information comes from a coil sensor installed in a copper
well attached to one of the lower circuits of the outdoor coil.
The defrost control board evaluates the delta between these two sensors and determines when the outdoor coil is frosted and needs a defrost cycle.
While the enabling parameters of a defrost cycle may vary by manufacturer, a defrost control board is looking for the ambient sensor input to be below 52F (11C), the coil temperature should be below approximately 35F (1.7C) and the unit must have operated in heating mode for more than two minutes. Once a defrost cycle becomes necessary, the control board will:
• De-energize the outdoor fan motor.
• Drive the electronic expansion valve to fully open.
• Command the reversing valve to change into cooling mode.
• Instruct the compressor to run at maximum cooling speed.
• Send a message to the indoor blower to operate at maximum cooling speed.
• Energize indoor auxiliary heat.
• A smart thermostat may indicate the system is in defrost mode.
• Defrost cycle will terminate when the outdoor coil temperature reaches 47F (8.3C) or some other temperature value as determined by the unit manufacturer and depending on the ambient conditions at the time.
• The defrost cycle may be terminated by time, typically 10 to 12 minutes in defrost will signal automatic termination.
• Too many defrost cycles terminated by time may indicate a fault in which a fault notification is sent to the indoor thermostat and may force the system into a degraded mode of operation called Limp Mode.
• Some units may have a communicating display assembly installed in the outdoor unit in which stored faults can be retrieved allowing the technician to determine the next steps.
Following are some suggestions to optimize heat pump performance keeping defrost cycles in mind.
When doing a site survey, choose a location that is reasonably protected from high winds. Otherwise, specify or build a manufacturer approved wind shield.
Vertical discharge units should not be installed beneath low or wide roof overhang or any area where water can drip into the unit from above.
Avoid nearby dense foliage or any other object (fences, walls, etc.) that may block free airflow or cause recirculation of air from the discharge to the inlet side of the unit.
The outdoor unit should be installed so that snow and ice cannot block the outdoor coil.
The outdoor unit should be mounted on a solid concrete pad on a stand that raises it high enough to prevent drifting snow from blocking the coil.
And be sure the interior of the cabinet is clear of debris (grass clippings, leaves, etc.) that might prevent meltwater from exiting via drain holes in the base pan.
It is unlikely anyone would purposely market an “energy wasting machine”, yet, in my experience with heat pumps, that is precisely what they become when installation oversights and shortcuts force the machine to run excessive defrost cycles.
Consumer complaints related to high energy bills and poor performance can, too often, be traced back to something so simple as too many errant defrost cycles. <>
Ian McTeer is an HVAC consultant with over 35 years of experience in the industry. He was most recently a field rep for Trane Canada DSO. McTeer is a refrigeration mechanic and Class 1 Gas technician. imcteer@outlook.com.
This multi-use resource centre in Sanikiluaq, Nunavut plans to be the area’s first net zero building.
Dealing with supply logistics and low-temp heating in Canada’s north.
BY DOUG PICKLYK
Sanikiluaq is Nunavut’s southernmost community, located about 150 km off the northwest border of Quebec among the Belcher Islands, an archipelago in the southeast section of Hudson Bay.
Among the newer buildings in Sanikiluaq is a roughly 5,000 sq. ft. multi-purpose research centre owned by the Arctic Eider Society, an Inuit notfor-profit organization dedicated to supporting Inuit-led stewardship and nature conservation in the area.
Positioned on a hill, the main floor of the building brings visitors into a com -
mercial space which includes offices, staff kitchenette, research labs, a large meeting room and a visitor’s foyer. The second floor provides temporary residence for rotating researchers including three bedrooms with ensuites, a shared living space and kitchen. The lower level is really just a crawl space which accommodates the mechanical room.
This mixed-use complex aims to be the first net zero building in Nunavut.
The project was led by Jeff Armstrong, the managing director at Cold Climate Building, a specialist in designing and building energy efficient structures in Canada’s far north, including a project with Nunavut Housing Corp. where he introduced structural insulated panel
(SIP) building systems to create well-insulated air-tight envelopes suited to netzero-ready structures.
The mechanical system in the new build was designed by Cameron Haines, P.Eng., of Southface Engineering, who was brought on board by the building’s design architect, Richard White.
The heating system is driven by three Nordic air-to-water heat pumps connected to two 70-gallon storage (buffer) tanks with integrated electric boilers.
“I love this type of system because the buffer tanks act like a battery, and they offer flexibility with being able to tie them into any type of future energy source or backup source that they may need,” says Haines.
The selected Canadian made air-towater heat pumps from Maritime
Geothermal in Petitcodiac, New Brunswick, are a split system design, with separate indoor and outdoor units. The outside section includes the air coil, fan, expansion valve, and outdoor temperature sensor. All other components, including compressor and electronics, are contained in the indoor units.
“The logic is really simple,” says Haines. “All the heat pumps have to do is keep the buffer tanks at the set point temperature (105F/41C).” Because it’s a really tight building, it allows for a low supply temperature. The heat loss calculation at design temperature of -30C was 128,000 Btu/h (37.5kW) for the building envelope, and Haines says their calculations show they could have gone as low as 95F (35C) for the supply heating temperature.
As designed, not all three heat pumps are operating at once, as Haines describes, they are set up so there is one master heat pump and then the other two are slaves, and that process rotates among the three to even out usage.
The plumbing and mechanical systems were installed by Candor Plumbing and Heating of Ottawa. The company has a history of working with Armstrong at his previous Nunavut projects. Fortunately, the crew took lessons from that experience when planning for this job.
“We had to load everything in three shipping containers here in Ottawa— that includes every elbow, every valve— and it was all packed in a way that it could be removed in the order of installation,” says Trevor Johnson, who helps run Candor along with his father Kim and brother Cory.
Johnson recalls how this process was an improvement compared to the last time when they found themselves cutting blocks of snow off of crates in the middle of the dark Arctic winter searching for the parts they needed.
Working on an island in the middle of Hudson Bay presents many challenges. Getting the crew on-site required flights connecting through either Winnipeg or Montreal, with the real prospect of cancellations and having to re-book the flights for days later.
In total the team took five trips, starting in January of 2022 when they were using a generator for temporary heating
(because it was minus 30 inside) and watching a thermometer waiting for it to rise to where the glue for the ABS piping would cure.
“We also lost the power to the building where we were staying that January,” recalls Johnson. During a blizzard they needed to crane the generator from the worksite—that was keeping that building
warm—to heat up their sleeping quarters, and then transfer it back to the worksite and start all over again the next day.
The primary loop from the heat pumps to the buffer tanks is all in 2-1/2-in. copper that was insulated. The space heating distribution system uses in-floor heating on the upper two floors as well as heating coils in the air handling units of two ERV ventilation systems.
Because of the geography there isn’t any type of mechanical cooling required for the space, but the building is ducted to allow free cooling using outdoor air. “Duct work is not something I do every day, so I was leaning heavily on Jamey Mackenzie of Mack Metal, our subcontractor for installing the duct work,” says Johnson.
Each room in the building is its own zone. When a thermostat calls, a zone valve opens and a low-power variable speed ECM circulator near the buffer tanks recognizes the opening and sends heat to that zone. There is a pump for each floor, and a third installed for redundancy. Those tanks are piped in parallel using circuit balancing valves. There are also two totes of glycol (antifreeze) in the system. “You take no chances when temperatures can dip to -40C,” says Johnson.
No concrete is used in this cold climate project, so the team used radiant panel flooring, a high-density polystyrene that comes with an aluminum heat transfer sheet on top and pre-set grooves for the PEX piping. The panels were secured on top of an additional layer of insulation board was placed on top of the subfloor, which was made of a well-insulated SIP panel. “There’s no shortage of insulation,” says Johnson.
Vinyl flooring was used on top of the radiant panels. There are also three en -
The made in Canada Nordic air-to-water heat pumps are a split system, with separate indoor and outdoor units. The air coil, fan, expansion valve, and outdoor temperature sensor are all located outside.
insulated and vinyl wrapped.
“When looking to go net zero, everyone seems to be moving towards heat pumps and in-floor heating.”
try way force flows for heating as well as a unit heater in the mechanical space.
The heat pumps have a double-wall desuperheater which is used for pre-heating the domestic hot water. That system leads to a 50-gallon storage tank with integrated electric boiler that holds the preheated domestic water that runs through a copper coil at 70F or greater, and then the domestic water goes through a second coil in another 50-gallon tank where it is brought up to a minimum of 140F.
As a back-up to the system, there is also an oil-fired boiler in the mechanical space that ties into the DHW tank, and it is also piped-up to supply the space heating distribution if necessary.
Currently, the electricity for the community is driven by diesel-fuelled generators. To offset some of that carbon-burning power the building has installed solar panels on the roof, and the owners anticipate tapping into a community wind turbine project on the island to get completely carbon free.
“Their net zero capabilities are a work in progress, but they shouldn’t have a problem getting there,” says Johnson.
And Haines agrees: “There’s a lot of wind up there, so that’s why the model was so positive towards net zero.” He adds that when looking to go net zero, everyone seems to be moving towards heat pumps and in-floor heating. “It’s one of the best systems to use because of the size of the heating area so you need very low temperatures which allows the heat pumps to operate at a very high efficiency.”
Johnson hopes that by sharing this project with the industry others will find inspiration in the simple possibility of achieving net zero building operations in the arctic. <>
HIGH-EFFICIENCY CENTRAL HEAT PUMPS WITH CASED COILS
Heat pump combination AHRI Certified for installation with ANY 3rd party furnace.
Eligible to financial incentives in certain provinces, contact us for more detail.
TO FULLY SUPPORT OUR DEALER NETWORK
DISTRIBUTOR
*GREE Canada is not responsible for warranty on units sold outside GREE Canada’s sales channel.
For more detail, contact our team at proservice@gree.ca
Despite challenges that may occur with future electrical demand, today’s heat pump technology is up to the task for this Canadian homeowner.
BY IAN McTEER
In a world where conversations once revolved around weather complaints and TV show character analyses, it now seems that the hottest topic (pun intended) around the water cooler is none other than heat pumps. Move over cat memes and conspiracy theories; the new kid on the block is a sleek, energy efficient, super quiet heating and cooling appliance that’s rapidly gaining celebrity status. Thanks to aggressive marketing, extensive media coverage, government and utility incentive programs including favourable impressions imparted during dinner parties, many people are impressed by heat pumps.
Heat pumps have become a world-
wide phenomenon. The European Heat Pump Association (EHPA) reported 2.2 million heat pumps were sold in 2024 among 14 countries which make up around 90% of the European market. EHPA estimates around 26 million heat pump units have been sold in the region, And while some markets are seeing a decline, heat pump sales in the UK grew 63% year over year thanks to government support programs.
In North America, governments at all levels and utilities are promoting and subsidizing heat pump installations and energy efficient upgrades. The City of Toronto has prepared a number of impressive heat pump case studies including several hybrid systems working along with forced air gas furnaces. The studies were prepared by The Sustainable Technologies Evaluation Program (STEP) of the Toronto and Region Conservation Authority (TRCA). The case studies are posted on the City of Toronto’s website.
“Everything should be made as simple as possible, but no simpler,” is a remark attributed to Albert Einstein. And it seems electrification of everything fits that philosophy, because as simple as it sounds to string a bunch of wires around town to power electric heating systems and to charge electric cars, it’s just not
The Canadian Federal Government wants Canada’s electrical grid to get to net-zero by 2035. Government modelling predicts an expenditure of more than $400 billion will be required to replace aging facilities, expand solar and wind power generation and to construct more interprovincial power transmission lines. A huge battery storage capacity will be needed to help the system to adjust to peaks in demand from electric heating systems and electric vehicle changing stations.
The International Energy Agency said in 2022 that Canada would have to triple its electrical grid capacity by 2050 to reach the net-zero goal, yet analysists think doubling or tripling needed capacity by 2035 is doable; provided we get started right away!
Mario Chiarelli, a Toronto-based energy efficiency consultant told CBC News that converting Toronto’s 650,000 natural gas heated homes to top drawer inverter heat pumps would still have the
effect of doubling the city’s electrical demand, increasing the load by an additional 5,000 megawatts.
No mention of the estimated electrical demand produced by the electrical conversion of residential apartment buildings along with institutional and commercial applications, many using gas-fired boilers.
While the analysts hold that grid improvements, energy saving retrofits and
battery storage technologies will help to reduce costs, it’s inevitable the price of electricity will rise in the short term.
Some idealists are convinced that energy costs could decline by as much as 12% by 2050 once the energy efficiency improvements have been made and reliance on volatile fossil fuel pricing has been circumvented by achieving the net zero goal.
It seems like such a monumental
task, and it’s hard for me to be anything other than skeptical about massive changes to the electrical infrastructure in such a short period of time.
I’m the only one on my street with 100% electric heat. Everyone else uses natural gas. On a cold winter day (operating below my -8F (-22C) balance point) with resistance heat and the outdoor unit operating together, my system requires approximately 45 amps in total.
My neighbour’s gas furnace draws approximately 6.5 amps to run the draft inducer, fan motor and low voltage circuits. Thus, [(45 – 6.5)/6.5] x 100 = 592.31% increase in amperage over my neighbour.
There are 20 houses on my street. Admittedly, I haven’t consulted with a hydro engineer about my local electrical infrastructure, but it makes sense to me that the above ground power lines on my street would not happily pass 592% more current without a major upgrade in wire and transformer size.
Electrification is a worthy goal, however, reupping the grid so that every building gets the electrical service it needs may take decades longer than planned.
In the U.K, where gas boilers once efficiently heated the average British home, air-to-water heat pump systems are being installed in ever increasing numbers. But not all is well, and Britain faces many of the same equipment related problems common to our own HVAC industry.
Too often units are improperly specified, existing systems are not properly evaluated for pipe sizing and flow rates, and accessories like large buffer tanks are installed in attic spaces with pipes running here and there.
The lack of qualified labour, seemingly a universal problem, means too Continued on p18
many systems simply don’t work as designed.
Comments and photos from across the heat pump world too often point to heat pumps failing to live up to advertised efficiency.
U.S. State Senator, William Brownsberger of Massachusetts, posted “mixed results” with his heat pump installation. He reported the system suffered a leak, but even after repairs were completed, he claimed the heat pump was so inefficient “that the environment would have benefited more if his family hadn’t installed it at all.”
I have read other comments like this, but typically no system details are ever reported. We will never know if the unit was properly specified, installed into an appropriate duct system, commissioned correctly and well maintained. The refrigerant leak was truly unfortunate, but it might point to the quality of workmanship rather than the unit itself.
When I see photos of outdoor units buried in snow, it seems to me the installers are not serious about heat pump performance (see Figure 1, page 16).
Since my Mitsubishi cold climate air-source heat pump unit was installed in September 2021, I can report excellent performance in both heating and cooling modes.
However, I’ve experienced several hiccups that cannot necessarily be blamed on the equipment.
I had one no heat situation in March of 2023. A horrendous ice storm knocked out power in our area for 75 hours. My allelectric system remained dormant throughout, and it was cold.
I now have a gas fireplace for backup. And on January 22, 2022, I ran out of heat as the outdoor temperature had dropped to -34C. My outside design temperature is -25C, and my system has previously maintained our preferred room temperature of 21.5C down to -30C without difficulty.
The extremely low temperature lasted only a few hours and
the room temperature was maintained at 17C, so no real complaint (Figure 2, page 17).
Controlling the system became an issue. I had requested a thermostat with an internet connection. At the time, Mitsubishi could not provide an internet-enabled digital controller for the system, so I opted for a 24-volt Ecobee thermostat to control my equipment using an interface.
However, there were communication problems in the heating mode that created a few no heat and even a couple of too much heat events. Sometimes the system did not start in the heating mode even though the thermostat was clearly calling for heat, several other times the system continued heating beyond setpoint.
I’m now using a Mitsubishi digital controller that works well, but I have no internet access to my system. I understand Mitsubishi will eventually have the type of controller I’m looking for, and I have nothing bad to say about the Ecobee thermostat, it’s a great product.
Perhaps the worst catastrophe to befall my heat pump system occurred in the spring of 2022. After several days of heavy rain combined with melting snow run-off from my septic drainage field and the roof of my modular unit (it took over a year to get my eavestrough installed!), a small river formed in front of my outdoor unit’s concrete pad and washed away a considerable amount of the gravel base, enough to undermine the pad so that it sunk down an inch along the front side.
The outdoor unit tipped noticeably forward, fortunately there was not enough stress on the line set to cause a leak.
After half a load of 5/8-in. base gravel and an afternoon’s worth of plate tamping, I managed to restore the integrity of the ground below and around the pad.
I did not risk raising the pad, I simply lifted the unit an inch and adjusted the legs so the unit is now level once again.
With the eavestrough now installed and a line of cedar trees planted in front of the unit to break the wind a bit and to prevent excessive drainage into the area around the heat pump, I’m confident that my unit will continue to perform as expected (Figure 3).
I would, wherever possible, recommend a cold climate heat pump like mine to anyone wanting to upgrade an older HVAC system to benefit from improved efficiency, quiet operation and top-drawer heating and cooling performance.
I’ve found it’s best not to consult social media for hysterical stories about heat pump failures, as too often those postings neglect to supply any crucial information about what we know goes into designing and installing a first-class heat pump system.
Based on my experience, I firmly believe there are plenty of hybrid and cold climate systems performing as advertised in Canada today.
I admire the efforts of industry groups and governmental agencies such as the aforementioned City of Toronto’s Sustainable Technologies Evaluation Program for leading the way in demonstrating how to evaluate the heating needs of a building, then to go about specifying suitable heat pump equipment carefully installed by experts.
Heating systems of all varieties are expensive, and governments tend to throw cash at programs that may or may not be environmentally beneficial.
Wouldn’t it be better to subsidize high school and community college shop classes, along with those studying the principles of building knowledge techniques such as improved insulation and
ventilation, rather than pay for secondrate heat pump installations?
Wouldn’t it be better to have one heat pump system working properly than to have two subsidized systems working poorly or not working at all?
While an emissions-free environment is a worthy goal, electrification of everything cannot occur without dramatic improvements to the electrical grid combined with an enormous expansion of our skilled labour force, and that, in my opinion, will take decades. <>
Ian McTeer is an HVAC consultant with over 35 years of experience in the industry. He was most recently a field rep for Trane Canada DSO. McTeer is a refrigeration mechanic and Class 1 Gas technician. He can be reached at imcteer@outlook.com.
BY DOUG PICKLYK
From modest beginnings as a Montreal-based regional plumbing and heating business, over the past 100-plus years the family-owned Carmichael Engineering company has embraced an adventurous entrepreneurial spirit and developed into a Canada-wide commercial, industrial and institutional HVAC service, maintenance and design-build contracting organization.
Founded by Ray Carmichael in 1922, today the company is led by Carmichaels’ grandson, Ray Jr., and has 23 branches and over 700 employees across the country.
In 2022 the business celebrated its centennial, while at the same time it began undertaking an ambitious project—designing and overseeing a ‘smart’ operational net zero building to serve as the branch office for its Belleville, Ontario location.
Carmichael made its name in service and maintenance and added energy services and design-build divisions over the years. Although the company performed energy projects for clients, designing the Belleville branch was their opportunity to walk the talk.
“We’ve been preaching this is the way to go,” says Carmichael’s Eric Rockarts, “Now we had to put our money where our mouth is by developing a building for our own team.”
Rockarts, a 30-year employee with the company, launched the Belleville location in 1998 and served as branch manager for 24 years. He formally retired in June 2022, and then he re -
joined as part of the company’s engineering and project management group.
The goal for the new office was an energy efficient building that would produce as much energy using solar panels as it would consume in a calendar year with almost no reliance on carbon-burning fuels. And using its own building automation system the team will be able to monitor and optimize the new building’s operations as it goes.
The new branch is around 22,000 sq. ft. in total, with Carmichael occupying 4,000 sq. ft. of office space in the front along with 6,000 sq. ft. of adjacent warehouse, and the building has two additional tenant spaces available for lease.
The warehouse and tenant section of the building is made up of pre-formed, pre-insulated, wall panels, and a double roof with about nine inches of insulation and materials. The south facing office space has well-insulated walls, a lower roof surface and tinted high-efficiency double paned windows, all providing a tight building envelope.
“We wanted to add solar panels, so our energy group ran the models, balancing cost versus achieving the goal of operational net zero,” explains Rockarts.
The solar installer was able to accommodate all the required panels on the building’s high roof, with the ability to generate 125 Kw of electrical energy. All the future modeling is based
Continued on p22
If you don’t have IGSHPA accreditation Your GSHP Customers can’t receive their rebates. You know you need it, but you don’t know where to go? Relax, it’s as easy as I, 2, 3-days in May! HRAI offers Canada’s ONLY IGSHPA Accreditation course. Get the training and get the customers. If you’re looking to renew your IGSHPA Certification, contact: training@hrai.ca
on that capability.
Initial design options included using geothermal or VRF, but ultimately the team selected LG air-cooled inverter scroll heat pump chillers for an air-towater system, the first installation of these units in Canada.
They installed two 20-ton units on the lower roof to provide the required heating and cooling. Using a glycol/water mix to prevent freezing, four pipes lead from the chillers into the building to satisfy either the hot water or chilled water buffer tank. The hot water tank is maintained at 114F (45.6C) and the chilled water at 44F (6.7C).
When there are calls for heating or cooling in the building, the system draws from the tanks to a heat exchanger, where the distribution system for the occupied spaces is then fed a water-only supply of hot or cool water.
“In January both chiller units would be in heating mode, and then come the shoulder seasons we can have chilled water and hot water working simultaneously. And, of course, cool water only in during the summer months.”
A back-up gas-fired Lochinvar Epic boiler is in place for supplemental heating if required, and it will only kick in below -15C.
The system is designed using low temperature in-floor radiant as the primary heating and hot water fan coils for zone
tempering. The fan coils are also equipped with chilled water coils for water-based cooling.
Using all ECM-driven fan coils, it is designed with heating coils downstream from cooling coils, so they can provide dedicated dehumidification.
“We’re controlling plus or minus 0.1F of set point in all spaces,” says Rockarts. The systems are all controled by electronic valves, and the building’s mechanical system is fully automated courtesy of Carmichael’s building automation system design using ABB-based controls.
“We also have Belimo Btu meters on everything,” notes Rockarts. “We know exactly where all of our energy is.”
As the generator of heating and cooling energy for the entire building, they can monitor all the energy heading to the tenant spaces providing the ability to charge for consumption.
Because it’s an industrial site the demand for domestic hot water is very low, so instead of incorporating DHW off the heating water loop the team is using a 40-gallon domestic hot water electric heater to manage demand.
The building operates a dedicated outdoor air system with ERV. “We wanted to precondition the outside air before it hit the fan coils, so it’s got an electric heater on the incoming air to take the chill off, but then it has post heating or cooling from the heat pump chillers,” explains Rockarts.
The system design provides preconditioned constant ventilation with CO 2 reset, whereby for all zones it calculates average CO2 and decides if it needs to increase fresh air or decrease to a minimum rate. “When there is no one in the office it will go down to a minimum ventilation rate to bring fresh air in, so the building starts fresh every day,” says Rockarts.
The basic build of the branch was completed in June 2023 followed by commissioning of the operations. The BAS system is constantly monitored by the company’s own secure cloud-based Performance Analyzer platform.
Carmichael moved into the building in mid-October and celebrated a grand opening in November with the Mayor participating in the ribbon cutting along with Maddie Carmichael, the fourth generation of the family to continue the legacy.
“As part of the new generation of Carmichael, we’re aiming to pioneer solutions that not only elevate the operation, efficiency and comfort of indoor spaces, but to pave the future for a greener world for generations to come,” said Carmichael, adding, “This building, in itself, represents the importance of, and our commitment to, sustainability.”
The Belleville branch is creating a template for future Carmichael facilities, including its Ottawa division already in progress. <>
Compresseur Inverter et moteur à vitesse variable
Capacité de chauffage/refroidissement jusqu’à 11 600 Btu/h
Polyvalence d’installation : dans le haut ou le bas du mur
Facilité d’installation et d’entretien
Télécommande (de série) et thermostat mural (facultatif)
Moteurs 115 V et 230 V monophasés en stock
Canada’s newest name in high-performance heat pumps.
NOW EXCLUSIVELY AVAILABLE AT MASTER
airHome systems are designed for all-season comfort with the smart features your customers want and the reliability you need.
• R32 refrigerant – low GWP, in use by Hitachi since 2013
• Built-in Wi-Fi with AirCloud Go™ app
• Reliable heating down to -30°C
• Motion sensor for smart energy savings
• FrostWash™ 3.0 self-cleaning coils
• Models: 400, 600, 800 & multi-zone
• PM2.5 active carbon filter – lab -tested for fine particles