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CAN CSA C746-17: Performance Standard for Rating and Testing of Heat Pumps and Air Conditioners
Understanding the Canadian Standard for Seasonal Efficiency Ratings in HVAC Systems
1. Scope and Application
CAN CSA C746-17, published by the Canadian Standards Association (CSA Group), is the governing document for the performance rating and testing of unitary air conditioners and heat pumps in Canada. It applies to equipment with a rated cooling capacity up to 19 kW (approximately 65,000 Btu/h), including single-package and split-system configurations. The standard defines uniform test methods and calculation procedures to determine cooling and heating capacities, power consumption, and the resulting seasonal efficiency metrics — Seasonal Energy Efficiency Ratio (SEER) and Heating Seasonal Performance Factor (HSPF). These ratings serve as the basis for compliance with Canada’s Energy Efficiency Regulations and are widely referenced by utilities for rebate programs.
The standard is harmonized with the U.S. standard AHRI 210/240 in many respects but is specifically tailored to Canadian climatic conditions. It uses distinct bin temperature profiles that reflect the heating and cooling load distributions across Canadian regions, ensuring that SEER and HSPF values are representative of actual energy consumption in Canada.
2. Technical Requirements and Rating Methodology
2.1 Standard Test Conditions
CSA C746-17 prescribes specific indoor and outdoor conditions for testing heat pumps and air conditioners in cooling and heating modes. For cooling, the full-load test is conducted at an outdoor dry-bulb temperature of 35°C and an indoor dry-bulb of 26°C. For the heating mode, two key test points are defined: a high-temperature test at 8°C outdoor dry-bulb (6°C wet-bulb) and a low-temperature test at –8°C outdoor dry-bulb (–9°C wet-bulb). Additional part-load tests are required to capture performance at reduced compressor speeds for variable-speed equipment. The table below summarizes the main test conditions for cooling mode:
| Test Condition | Outdoor DB (°C) | Outdoor WB (°C) | Indoor DB (°C) | Indoor WB (°C) |
|---|---|---|---|---|
| Full Load (A) | 35.0 | 23.9 | 26.7 | 19.4 |
| Part Load (B) | 27.8 | 19.2 | 26.7 | 19.4 |
| Part Load (C) | 30.0 | 21.1 | 26.7 | 19.4 |
Note: The indoor wet-bulb temperature of 19.4°C (≈50% RH) is used for all tests to maintain consistent latent load conditions as specified in the standard.
2.2 Calculation of SEER and HSPF
SEER is calculated using the bin method, which weights the cooling capacity and power at each outdoor temperature bin by the number of hours that temperature occurs in a typical Canadian cooling season. The standard provides two calculation methodologies: the simpler single-speed method for fixed-capacity equipment and a more detailed approach for variable-speed and multi-speed units. HSPF is computed similarly, using heating season bin hours and considering the energy consumed by supplemental electric resistance heat when the heat pump capacity is insufficient.
Design Tip: When developing variable-speed products for the Canadian market, ensure that performance data are collected at all required part-load points defined in CSA C746-17. Missing part-load data can lead to an understated SEER or HSPF and may disqualify the unit from certain regulatory certifications.
3. Implementation in Product Development and Certification
Manufacturers intending to sell air conditioners or heat pumps in Canada must design their products to be tested in accordance with CSA C746-17. The standard is recognized by Natural Resources Canada (NRCan) as an approved method for demonstrating compliance with the minimum energy performance standards (MEPS) for these products. In practice, this means that:
- All tests must be conducted by an accredited third-party laboratory using the specific apparatus and instrumentation described in the standard.
- Ratings derived from CSA C746-17 must be reported on the Energy Guide label and in product literature.
- For heat pumps, both SEER and HSPF must be disclosed, and the equipment should meet or exceed the current regulatory thresholds (e.g., a minimum SEER of 13.0 for split systems, though this value is subject to periodic revision).
The standard also includes provisions for testing at low ambient temperatures and for measuring standby power consumption, which are increasingly important for accurate seasonal performance assessments.
Compliance Success: Using CSA C746-17 as your testing basis ensures your equipment is eligible for Canada’s ENERGY STAR® program and many provincial utility rebate incentives, provided the achieved SEER/HSPF meet the required levels.
4. Compliance with Canadian Energy Efficiency Regulations
CAN CSA C746-17 is referenced directly in the Canadian Energy Efficiency Regulations administered by NRCan. Any manufacturer or importer of covered products must ensure that their equipment is tested and certified by an accredited certification body (e.g., CSA Group, UL, or Intertek) to the methods of C746-17. Failure to comply can result in penalties, prohibition from sale, and loss of market access.
It is important to note that while CSA C746-17 shares many test methods with AHRI 210/240, the seasonal efficiency ratings are not interchangeable. The Canadian bin hours for both cooling and heating are different from those used in the United States, leading to possible discrepancies in reported SEER and HSPF values. Manufacturers must maintain separate ratings for the Canadian market.
Critical Warning: Do not assume that US-rated SEER/HSPF values will automatically meet Canadian regulatory minimums. Always recalculate according to CSA C746-17 bin hours and submit to an accredited Canadian certification body.
The standard was reaffirmed in 2017 and is currently under review for a scheduled update. Although the core test methods remain stable, amendments may be introduced to address new technology (e.g., heat pumps with variable refrigerant flow) and more stringent efficiency targets. Manufacturers should monitor CSA Group’s announcements to stay current.
5. Frequently Asked Questions
Q: What is the main difference between CSA C746-17 and the U.S. standard AHRI 210/240?
A: The primary difference lies in the bin temperature profiles used to calculate seasonal efficiency. CSA C746-17 uses bin hours that represent Canadian climatic conditions, resulting in SEER and HSPF values that may be higher or lower than those calculated under AHRI 210/240 for the same equipment. The test methods are largely harmonized, but the rating outputs are tailored to each market.
A: The primary difference lies in the bin temperature profiles used to calculate seasonal efficiency. CSA C746-17 uses bin hours that represent Canadian climatic conditions, resulting in SEER and HSPF values that may be higher or lower than those calculated under AHRI 210/240 for the same equipment. The test methods are largely harmonized, but the rating outputs are tailored to each market.
Q: What are the current minimum SEER and HSPF requirements in Canada?
A: As of the latest amendment (2024), the minimum SEER for split-system air conditioners and heat pumps is 13.0, and the minimum HSPF is 7.1 (Region V). However, these values are subject to change with regulatory updates. Always consult the current NRCan regulations or CSA C746-17’s latest edition for the most up-to-date thresholds.
A: As of the latest amendment (2024), the minimum SEER for split-system air conditioners and heat pumps is 13.0, and the minimum HSPF is 7.1 (Region V). However, these values are subject to change with regulatory updates. Always consult the current NRCan regulations or CSA C746-17’s latest edition for the most up-to-date thresholds.
Q: Does CSA C746-17 apply to ductless mini-split heat pumps?
A: Yes, the standard covers unitary equipment with rated cooling capacities up to 19 kW, which includes ductless mini-splits. However, certain provisions for multiple indoor units and refrigerant line lengths may require additional testing per applicable annexes or companion standards (e.g., CSA C748 for variable refrigerant flow systems).
A: Yes, the standard covers unitary equipment with rated cooling capacities up to 19 kW, which includes ductless mini-splits. However, certain provisions for multiple indoor units and refrigerant line lengths may require additional testing per applicable annexes or companion standards (e.g., CSA C748 for variable refrigerant flow systems).
Q: How often does CSA C746 get updated?
A: CSA standards are typically reviewed every five years. The current edition is C746-17, which reaffirmed the 2011 edition. A new edition is expected soon. Manufacturers should participate in the standards development process to keep abreast of pending changes.
A: CSA standards are typically reviewed every five years. The current edition is C746-17, which reaffirmed the 2011 edition. A new edition is expected soon. Manufacturers should participate in the standards development process to keep abreast of pending changes.