Perfect Comfort for Every Room in the House - Ontario, Canada


Ontario, Canada, has a continental climate that experiences hot, humid summers and very cold winters. When Ontario homeowner Sylvana Tressler’s 23-year-old HVAC system failed, she saw it as an opportunity to replace it with a more effective system that would ensure year-round comfort in their 1,800 sq. ft. home.

“We are very pleased with the system…it is exceptionally quiet and very efficient.”

– Sylvana Tressler


The Tressler home’s original HVAC system consisted of an 11 SEER 2-ton AC unit and a condensing gas furnace with matching coil. Over the years, the AC unit had become extremely noisy, and the system was struggling to maintain indoor comfort on high-humidity days. The system’s inefficient energy use and high carbon emissions made Sylvana feel guilty every time it turned on. Moreover, the 2-ton AC unit had no spare capacity, so any room additions would require a separate heating and cooling solution.


Working with Comfort Masters of Oshawa, Ontario, the Tresslers decided to upgrade and replace the entire HVAC system with a Lennox® Mini-VRF system. The new setup included a 17.8 SEER 3-ton Mini-VRF unit, AHU kit, SLP98V® gas furnace with matching CX35 coil, a Healthy Climate humidifier, and a Healthy Climate® MERV 16 filter. While only 2 tons were needed to heat and cool the home, the extra capacity offered by the 3-ton system allowed Sylvana to add a wall-mount VRF indoor unit (Model Number: VWMB009H4-3P) in the garage workshop. Paired with a VRF WiFi Controller to take full advantage of modulation features and the dehumidification cycle, Sylvana reported the thermostat was easy to set up and the app works great.


Designed for ease of installation, it took Comfort Masters only 1.5 days to change out and commission the new Mini-VRF system. The outdoor unit’s small footprint allowed it to fit neatly on the wall where the old AC unit had been mounted. Inside, the Mini-VRF unit connected seamlessly with the CX35 coil on the gas furnace and the indoor wall-mount VRF head, creating two comfort zones in the home. Since the new indoor pieces were nearly identical clearance to the previous setup, the Tresslers gained a more efficient system at higher capacity without losing any space in their basement. 


For Sylvana Tressler and her family, the Lennox® Mini-VRF system has been a complete game changer in terms of year-round climate control, customized comfort, and energy savings. 

You only turn on indoor units when needed, compared to a typical zoning system where cold or hot air is bypassed and sent back to return air of the indoor unit.


The Mini-VRF unit’s quiet operation significantly decreased indoor and outdoor sound levels to a low of 41 decibels from the nearly 70 decibels of the traditional AC. Upgrading from 11 SEER to a 17.8 SEER system resulted in a considerable reduction in electricity consumption, especially during the summer months. Gas utilization also decreased, thanks to the switch from a 91% AFUE furnace to a 98.8% AFUE high-efficiency one. Overall, this efficient dual-fuel system has enabled the Tresslers to optimize operating costs, reduce energy consumption and minimize the system’s carbon footprint—all without sacrificing comfort or indoor air quality.

Sylvana Tressler reported that, “My whole family notices a significant difference in the comfort level in the house. We enjoy much more consistent temperatures, very quiet operation and the humidity level is so much more enjoyable.”


The Tresslers’ old HVAC system could not regulate humidity and could barely hold the indoor temperature at 25°C (77°F). The new Mini-VRF system easily and consistently maintains relative humidity at between 45-55% and the indoor temperature at 21°C (70°F). This ability to more precisely control temperature and humidity has made a big difference to the Tressler family’s comfort. Ontario often experiences cool and very humid days in the spring and autumn seasons, so it can be a challenge to keep the home comfortable. With the Mini-VRF system in Dry Mode, the indoor humidity can now be successfully reduced, without overcooling the space.


A Mini-VRF system can be connected to multiple indoor units and can be used to create up to 9 zones from a single system. For the Tresslers, only two zones were created to meet their current indoor climate control needs, but they now have the flexibility to add more zones, should the need arise. Upsizing the system for future expansion is also a benefit of which the Tresslers can take advantage. And, because the gas furnace that the Tresslers installed is compatible with energy-saving thermostats, they could be eligible for rebates from their local utilities provider—which is another money-saving benefit offered by this feature-rich Mini-VRF system.

Download the Lennox Commercial VRF case study PDF

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