This March, HSC closed out a year of incredible change due to the COVID-19 pandemic, during which we, like many of you, had to rethink and pivot our operations. In this issue of Energy Matters, we look back on the pandemic’s impact on utility use trends, share updated ASHRAE recommendations to help you maintain safe and efficient operations as we enter the second year of the pandemic, and look to the future with a deep energy retrofit that is sure to be a template for energy saving projects to come.
We hope you enjoy this issue!
In this Issue:
- One Year Later: The Pandemic’s Impact on Social Housing Utility Use
- COVID-19 Recommendations for a Safe, Efficient Building
- Hamilton High-Rise Goes from Disrepair to “EnerPHit” for the Future
- UMP Reports: View Your Overall Performance for 2020
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One Year Later: The Pandemic’s Impact on Social Housing Utility Use
This March, we marked one year since the COVID-19 pandemic took centre-stage, significantly altering the way many of us live and work. With most Ontarians spending more time at home, residential utility use saw an immediate increase, even as Ontario’s overall energy consumption dropped. We expected to see similar changes in social housing, so to test this out, we analyzed the utility data of over 800 social housing buildings in our Utility Management Program (UMP).
We chose a five-year period for our analysis and accounted for differences in weather and billing cycles over the various years of data. Doing so enabled us to generate an apples-to-apples comparison of utility use across different climate regions and time periods. It also enabled us to attribute any changes we saw to behaviours of residents and staff or changes in equipment efficiency.
Note that because data is still coming in for January to March 2021, our commentary focuses on the March to December 2020 period.
Compared to electricity and water use, natural gas use changed the least in 2020.
Gas use throughout 2019 and into early 2020 was considerably higher than in previous years. After the pandemic began, gas use through the spring and fall of 2020 largely returned to levels seen in 2016 to 2018. Summer gas use, while lower than that of 2019, was slightly higher than previously seen in 2016 to 2018 summer months.
We might have expected gas used for heating to increase since the start of the pandemic due to more people staying home throughout the day. However, in buildings with gas-fired central heating plants, providers largely control unit temperatures and they would likely have maintained the same set temperatures for heating equipment as prior to the pandemic. The decrease we saw in spring and fall 2020, relative to 2019, could have been due to the fact that less heat is lost from a building when fewer people are going in and out of units and exterior doors. It could also reflect potential improved maintenance of heating and ventilation equipment by providers, given that improving ventilation is one recommendation issued by Public Health officials to limit transmission of the virus.
With more people at home, we might expect to see more gas used to heat water for showering, dish washing, and cooking. To check for this, we looked at summertime gas use, when space heating is shut down and gas is used mainly for water heating. We found that the gas use from June to October 2020 was lower than for 2019, but was, on average, 7% higher than the same months of 2016 to 2018. If we assume 2019 was a period of unusually high gas use, we could conclude that more gas was used on water heating after the pandemic began.
While gas use has not significantly changed since March 2020, gas pricing has been very volatile and generally high. Any providers who are on a market rate would have seen this volatility reflected in their on-bill gas commodity rates.
As with gas, we might expect electricity use to increase since last March given more people were at home to use electric space heating, appliances, and electronics through the day. Instead, we found that 2020 had the second lowest overall electricity use of the 2016 to 2020 period.
This finding was particularly surprising given that residential electricity use in Ontario increased by 14% from March to April 2020. In fact, the provincial government provided temporary electricity rate relief that helped residential customers offset the costs of any increased home utility use in the first year of the pandemic.
However, we did see a significant increase in summertime electricity use in 2020 for social housing buildings compared to prior years. This increase was likely associated with much higher use of air conditioners in 2020, which makes sense given more people were at home during the day during the hot summer months.
Of the three utilities, water showed the biggest change with higher use in almost every month since March 2020. The increases are likely due to what we would expect – more people being home, doing dishes, flushing toilets, bathing etc.
As we enter the second year since the pandemic began, we expect to see further fluctuations to utility use as lockdown orders are eventually lifted across the province and more people start returning to work.
Providers considering energy and water efficiency upgrades, or those who have recently completed improvements, should keep in mind that the 2020 data may not accurately reflect the true savings achieved due to the changes seen in tenant behaviour as a result of multiple lockdowns. The past year, however, could support the case for implementing further efficiency measures given that this is unlikely to be the last pandemic. The more efficient, resilient and safe our buildings are, the better positioned we will be to tackle whatever comes our way in the future.
COVID-19 Recommendations for a Safe, Efficient Building
From using PPE and signage, to increasing sanitization and limiting staff-resident contact, social housing providers have worked diligently over the past year to put safeguards in place to reduce the spread of COVID-19. Along with these measures, the Public Health Agency of Canada (PHAC) advises that improving indoor air ventilation and filtration can help reduce transmission of, and exposure to, the virus indoors.
A valuable resource for ventilation guidance, both during the pandemic and generally, is the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). This past January, ASHRAE updated its recommendations for reducing airborne infectious aerosol exposure in buildings of all types.
Along with this general update, the following ASHRAE resources focus specifically on residential buildings:
- October 2020 Residential Building Guidance
- June 2020 COVID-19 Guidance for Multifamily Building Owners/Managers
- FAQ for Residences
- FAQ on Filtration and Disinfection
- Handbook Chapters on specific heating, ventilation, and air-conditioning (HVAC) systems and equipment
Summary of Recommendations
Below is a summary of the key recommendations found in the above resources for both multi- and single-family housing:
- Inspect, maintain, and repair HVAC equipment, ducting, and outside air intakes.
- Maintain comfortable thermal conditions, such as a temperature range of 20-25 Celsius and 40-60% relative humidity.
- Increase ventilation rates to achieve at least the minimum intended indoor/outdoor air exchange, listed on your equipment, provided thermal comfort requirements are maintained.
- Install high-efficiency media filters in buildings with forced air system (e.g. rating of MERV 13 or best the system can accommodate).
Operators of multifamily buildings can also aim to:
- Ensure water is in the U-shaped trap in all plumbing drains and U-shaped traps are not allowed to go dry.
- Maintain pressurization through appropriate use of exhaust systems to keep in-suite space below the pressure of corridors.
- Seal large openings including chases and bypasses that can allow air to flow into the unit.
*Note that the ASHRAE recommendations should be considered as supplemental to those of public health agencies.
Comfort, energy use, and costs were identified by ASHRAE as possible constraints to achieving virus exposure reduction goals. However, it should be noted that several recommendations, such as sealing openings, maintaining equipment, and installing high-efficiency filters, can contribute to overall building energy efficiency even as they help keep residents and staff safe.
Because the virus may spread more readily in indoor spaces, a focus on ventilation can be an important strategy to include in your COVID-19 toolkit. Of course, as with any strategy, it is most effective when used as part of a multifaceted approach that also includes physical distancing, wearing masks, and proper and increased sanitization.
Hamilton Highrise Goes from Disrepair to “EnerPHit” for the Future
CityHousing Hamilton (CHH) has just about completed a deep energy retrofit of its Ken Soble Tower, an 18-storey, 146-unit building located at 500 MacNab Street North. CHH hopes this project will be used as a demonstration for what can be achieved with much needed apartment renewal across the country.
What makes this project special is that it will be North America’s first Passive House (PH) high-rise retrofit. CHH has adopted the ambitious goal of making all new social housing buildings it develops high-performance, using PH as an achievable nearly net zero energy standard. With the Ken Soble project, CHH saw an opportunity to leverage energy efficiency funding to complement a comprehensive asset renewal with a high-performance retrofit that would meet 2050 Federal climate goals now, and inform further sector adoption as many owners consider options for upgrading aging towers.
Because it is not always possible to apply the full PH standard to refurbish existing buildings, CHH pursued the Energy Retrofit with Passive House Components, or “EnerPHit,” certification. According to Passive House Canada, EnerPHit achieves the major improvements in thermal comfort, structure integrity, cost-effectiveness, and energy requirements that PH is known for, but is specifically geared to retrofits and allows flexibility to address the challenges of refurbishing older buildings.
The building was in significant disrepair, so was already empty when the retrofit began. The base conditions included extremely high energy use for heating, holes in fire separations between units, mould in interior walls, asbestos-containing materials, thermal bridging at slab edges, spalling brick, and deterioration of the central ductwork, flooring, windows, roof, plumbing, and electrical systems. In fact, the bulk of the budget went to asset renewal to extend the life of the building, while the incremental cost to pursue EnerPHit represented 7% of the total budget.
Utility Efficiency Measures
To meet the EnerPHit criteria, CHH undertook the following measures:
- Heating: The improved, super-insulated building envelope at 500 MacNab helps prevent heat transfer in and out of the building, thereby reducing the need to install a major heating system such as boilers. To handle the building’s smaller heat load, CHH installed Energy Recovery Ventilators (ERVs) that capture heat from exhaust air to preheat fresh air coming in the building. A centralized cold climate heat pump system then further heats the air to the set temperature. The air is circulated through the building using the existing ventilation system, which was refurbished to include direct ducting to bring the air into each suite. Tenants can control the temperature in their suites using variable air volume (VAV) units, which act like dampers to allow or restrict air flow in the suite. Tenants’ thermostats are networked into a building automation system (BAS), and when the BAS detects a significant temperature change in a unit, such as when a window is opened, the system pauses any additional air flow into the suite at 20-minute increments to prevent energy waste.
- Fresh Air Supply: Used the existing but modernized risers to provide improved fresh air supply on a floor-by-floor basis, with direct ducting in the corridor and into each unit. This approach is superior to the original (and no longer recommended) approach of corridor pressurization with door undercuts.
- Cooling: CHH implemented multi-stage cooling through a combination of an R-38 envelope, low emissivity glazing and interior shades to reflect heat inside in winter and away in summer, large operable windows at the Juliet balconies, in-unit ceiling fans, central dehumidification, and active cooling through the centralized heat pump. Using climate modelling data for 2050, CHH determined there was a need to add active cooling to maintain comfort as the number of extreme heat days increases and to address potential high humidity that can occur in air-tight buildings.
- Air-tight Façade: Targeted an air-tight, R-38 effective system using low carbon, non-combustible insulation.
- Insulation: Considered a double-wall assembly applied to exterior at first, but faced with concealed mould in interior walls, CHH took a more traditional approach of 4” insulation on the interior, fluid-applied air barrier and insulation on the exterior, with a 6” mineral wool Exterior Insulation Finishing System (EIFS) system. While more work, this approach was less expensive since it was already familiar to contractors. The mineral wool was also an environmentally attractive choice.
- Windows: Installed triple glazed PH-certified windows, mounted on fiberglass clips with silicon transition strips instead of tape.
- Balconies: Replaced the existing balconies with Juliet balconies as a cost-driven and operational decision. The existing balconies were a source of heat loss due to significant thermal bridging. The new Juliet balconies, which are essentially large windows with protective railings, reduce thermal bridging, provide access to fresh air, and maximize floor space.
CHH is targeting a minimum 70% decrease in overall energy intensity and 94% reduction in greenhouse gas emissions. The total energy required to heat or cool each unit will equal the energy required to run 3 incandescent 100W light bulbs.
Key Metrics: Before and After Construction
|Statistic||Before||After (As of March 30, 2021)|
|Annual heating energy requirement per sq. meter||250 kWh||22.3 kWh|
|Annual cooling energy requirement per sq. meter||none||1.9 kWh|
|Annual primary energy requirement per sq. meter||650 kWh||145 kWh|
|Air tightness (air changes per hr at 50 Pascals of pressure)||5.41 ACH||0.235 ACH|
In pursuing the Passive House EnerPHit standard, CHH has transformed 500 MacNab Street North from a high-rise in significant disrepair into a modernized, accessible, ultra-low energy 146-unit building. The resulting retrofit will have significantly reduced operating and maintenance costs, making it more affordable for CHH and its residents. In order to meet federal funding and other requirements, the end product will also achieve:
- A spectrum of renewed deeply affordable units.
- Resilience to extreme climate events, including the ability for residents to shelter in place for at least 4 days during peak-winter power outages.
- Aging-in-place principles, such as program support and accessible units.
- 30-year-plus asset renewal targets, having addressed all State of Repair issues.
- Barrier-free requirements on 20% of units and all public spaces.
- Support for tenants through the addition of new community spaces and partnerships with social service agencies to provide program support such as physical activity and art classes.
This ground-breaking project did not actually break ground through redevelopment – instead, by retrofitting the existing structure, it has laid the groundwork for thousands of high-rises to transform into sustainable, ultra-low energy buildings.
Interested in more information? See these resources:
- Case study: Raising the bar on community housing retrofits – Federation of Canadian Municipalities
- March 2021 Webinar and June 2020 Webinar (start at 12m:30s), Case Study, and Presentation – ERA Architects
- Project Feature – Entuitive (Building Envelope Engineers)
UMP Reports: View Your Overall Performance for 2020
It’s that time again! We’ve added your utility data into UMP up to the end of 2020.
Log-in to UMP to view your latest UMP dashboards and Gas, Electricity, and Water reports. Plus, we’ve updated the Annual Summary Report so you can view your overall performance for 2020.
If you’re not sure how to interpret your data, contact HSC Energy Services – we’d be happy to help!
Other Topics? If you’d like to suggest a topic or want a one-on-one review with HSC staff, please contact us!