Bob: Etobicoke’s Cleantech Maverick Offers Rooftop Tours!

Nestled at the end of a quiet cul-de-sac in Etobicoke, it’s not immediately obvious that Bob’s home has been kitted up with some killer cleantech. Originally built in 1965, Bob and his wife moved in just over 40 years ago and raised their two sons here. More recently, thanks to a clever set of upgrades, the home has a new responsibility. Bob’s home is a shining example of how older Toronto homes can be retrofit to achieve close to net-zero. (A net-zero home produces as much energy as it consumes.)

As the former owner of one of Toronto’s largest HVAC companies, and a long-time energy efficiency advocate, Bob is an expert at designing mechanical systems for optimal comfort and efficiency. As a parent and grandparent that is worried about the climate crisis, Bob decided to roll up his sleeves and design a home heating system that everyone could love.

Knowing the HVAC industry, Bob was keenly aware that for a solution to be adopted at scale, it needs to be cost-competitive to operate. Bob’s solution was to install a heat pump with gas back-up provided by a high-efficiency condensing boiler. Having tested this system over two winters now, Bob has proven that by using just a bit of gas for auxiliary heat during very cold weather, his heat pump configuration can operate for less than heating with a gas furnace.

In addition to purchasing and installing the heat pump himself (at 79 years young!), Bob also invested in a rooftop solar array. When he bought the home in 1979 he probably wasn’t eyeing the flat roof for anything except potential leaks, but years later that south-facing flat roof would prove to be absolutely perfect for generating electricity.

To say Bob loves his solar array is an understatement. I've toured the roof (it’s fun and safe!) and I’ve seen some of his summer hydro bills showing he’s in a credit position. Because Bob’s electricity is pretty much free now that he’s purchased a solar array, he didn’t really need to install gas backup for his electric heat pump, but again he wanted to design a system that would work in every home and was irrefutably low-cost to operate.

Indoor heat pump unit

Bob designed a “hybrid” heat pump solution which refers to using gas for backup. Knowing he also wanted to use gas for hot water, Bob purchased a boiler that could perform double duty. His boiler now provides on-demand hot water and it helps the heat pump in only the coldest weather.

So how does the boiler boost the heat pump? The boiler provides hot water to a hydronic coil that is mounted in the upper section of the heat pump’s indoor air handler. Inside the air handler is a heat exchanger that transfers heat from the hot water to the air that is about to be circulated through the home. This hydronic heating coil is large enough to heat the entire house but as Bob’s goal is to minimize carbon emissions, he only uses it sparingly.

Bob’s new heat pump is a 3-ton Mitsubishi Zuba Central, sort of the “Tesla” of heat pumps. It’s outdoor and indoor fans are incredibly quiet and it provides heating at temperatures as low as minus 27◦C. Inside his mechanical room is the Mitsubishi air handler that is boxy like most furnace and air conditioning equipment. Like all heat pumps, the Zuba provides Bob’s home with both heating and air conditioning. In the fall and spring, heat pumps are generally cheaper for heating than gas, so Bob only needed a cost-competitive solution for the coldest days when gas is still the cheapest.

This wall-mounted boiler provides domestic hot water and provides back-up heat for Bob’s home on the coldest of days.

Bob’s system is designed so that the gas heating coil and the heat pump automatically sync their operation with each other. Based on the outdoor temperature, they each peform as needed to minimize emissions and keep Bob’s heating costs low.

Bob’s heat pump provides about 80% of his home heating and the gas-fired heating coil provides the remainder. This means he’s reduced his annual carbon emissions by an estimated 5-6 tonnes annually. From the outset, Bob has been carefully tracking his energy use and costs so his system’s efficacy is well documented.

Another brilliant part of Bob’s solution is that it only requires two pieces of equipment for a home: a heat pump and a boiler. Most of us with central air have three pieces of equipment: a furnace, an air conditioner and a hot water heater. Over time, Bob’s capital costs should be lower than the rest of us because he’s replacing less equipment.

There are other “hybrid” (heat pump/gas) configurations out there but they aren’t nearly as slick as Bob’s. A common approach is to keep your furnace and place a heat pump on top where the air conditioner used to go. However this is an all or nothing situation because only one appliance, either the furnace or the heat pump, can be on at a time. This means once you turn on your furnace, you only use gas for heating, even on warmer winter days when your heat pump would have cost less and emitted less. However, there are switching technologies that are coming along. The other problem is that you’re typically sizing the heat pump for fall and spring use only, so you’ve entered a cycle of probably buying another gas furnace down the road, plus whatever you need for hot water on top of that. In Bob’s hybrid configuration, he can stop using gas for home heating whenever he wants, no problem (except that would mean cold showers, unless he electrifies his hot water too!)

Speaking of hot water, I left out one additional job Bob’s boiler does. Not everyone likes instant/on-demand water heaters because you wait longer for hot water than if you had a tank. Bob’s workaround is that his boiler also heats a small auxiliary tank of hot water for immediate domestic use. It’s about ⅓ the size of a regular tank and highly insulated for efficiency. If this little tank drains down a bit, say during a shower, the boiler kicks in to provide uninterrupted hot water for as long as it’s needed. On-demand hot water is pretty common but Bob’s system is luxurious because you don’t have to wait for it.

Sadly not all of us get to live with an HVAC wizard (I haven’t even mentioned his zoned temperature controls!) but the next best thing is available. Bob is happy to provide advice and tours if you want to see his heat pump and solar setup. Just contact Goldfinch and we’ll put you in touch. A smart system like Bob’s makes switching to a heat pump an easy decision that everyone can get behind.

Barbara: Getting Off Gas in The Danforth

Barbara lives in a beautiful 2 ½ story home just north of Danforth Avenue in Toronto. A lawyer by trade, she also has one son and one nephew, both of whom were constantly reminding her about the climate crisis and how awful natural gas is.

Three years ago she decided she needed to do something (if only to keep her son & nephew quiet!) and started figuring out what to do. It wasn’t easy, a lot of HVAC companies predominately install gas furnaces and many tried to dissuade her from making the switch from a gas furnace to heat pumps. However, Barbara persisted and is glad she did as she’s discovered that heat pumps are a really versatile and cost-effective way to heat (and cool) a home.

I recently visited Barbara’s home (while wearing a mask) to learn more about her fuelswitching experience.

Before fuel switching from a gas furnace to electric heat pumps, Barbara also wanted to understand her home’s overall efficiency so she hired an energy advisor. The advisor visited her home, ran some tests and provided her with an EnerGuide (an energy audit program run by NRCan) to guide some efficiency upgrades. Although people tend to think of replacing windows to reduce heat loss, Barbara had some wise advice to look at her walls instead. If you replace glass windows, sure you end up with less leaky windows, but they’re still glass openings. If you instead think about insulating your walls, it’s like adding a cozy thermal blanket around your home. To improve her home’s thermal envelope, she removed some of the old walls and built new framed walls that could be insulated behind the drywall. Barbara also installed a new, airtight front door. 

Although heat pumps can be centrally ducted, just like furnaces, Barbara’s home warranted a different approach. To free up precious ceiling space in her basement (that was being taken up by her ductwork) she went with “ductless” technology which places indoor units in various rooms of the home. Ductless systems are incredibly advantageous because each indoor unit has its own remote thermostat. For Barbara’s home, with four adults living on four different floors, this means no fighting about the temperature. Everyone gets the freedom to set their heat pump to the temperature they like, ensuring perfect comfort in each room, year round. 

Shown on the left is one of the indoor units and to the right is one of the outdoor units. Electrical, controls and refrigerant are all run via cables between the indoor and outdoor units. Finding the right HVAC installer is important as the location of both outdoor and indoor units is critical.

The baseboard heating in Barbara’s bathroom.

As an early adopter, Barbara wanted some back-up heat just in case (the city also required it for her basement apartment). Barbara purchased some electric baseboard heaters from her local hardware store for $60. Even though the baseboards are there, she and her roommates have found that the heat pumps provide more than enough heating even during the coldest days in winter.

As for the bills? Barbara’s costs have gone down. Thanks to her insulation strategy, Barbara saves about $100 a month, uses a quarter of the gas (she still uses gas for her hot water and stove) and is far more comfortable. Best of all, her son and nephew are proud of her for slashing her home’s emissions. 

Goldfinch Energy keeps finding that smart home retrofits like Barbara’s go hand-in-hand with improved overall comfort. Contact Goldfinch for expert advice on a heat pump configuration that makes sense for you and your home.