HPAC Magazine

Standardized HVAC Enhancements

May 13, 2024 | By Ian McTeer


The introduction of the SEER2 and HSPF2 Standards for residential HVAC equipment ensures improved energy efficiency across the board.

(photo: Getty Images)

The ever-escalating desire of many governments to shrink their so-called environmental footprints means the air conditioning industry has been leveraged once again to make a significant step forward in the area of energy conservation.

With the introduction of the regulatory framework for SEER2 (Seasonal Energy Efficiency Ratio, Version 2) on January 1, 2023, all HVAC manufacturers were further tasked to address and to mitigate the energy consumption associated with air conditioning equipment.

As concerns about climate change intensify, SEER2 emerges as a pivotal player in the ongoing pursuit of reducing energy usage. The long-standing SEER program may be moot to most well-informed readers, but I think we ought to delve into the intricacies of SEER2, examining its implications for the industry and the broader goal of fostering energy-efficient practices in cooling technologies.

Energy Conservation

Energy shortages threaten to become more acute as each year passes. I am old enough to remember the early 1970’s when a gallon of gasoline cost $0.25 per gallon and an attendant checked my oil and washed the windshield, front, and rear!

The family heating bill amounted to roughly one-quarter of the food bill. However, everything changed after the OPEC oil cartel implemented a crude oil embargo in 1973 causing the U.S. to suddenly find itself dramatically short of fuel.

Rationing of gasoline and worries about the availability of home heating oil supplies inspired law makers to act and starting in 1977, the U.S. Department of Energy (DOE) began development on a framework for a comprehensive national energy plan. The Canadian government, in large part, has aligned many of our energy policies with DOE initiatives.

Now, the overriding fear of governments, utilities and consumers alike is the ever-present threat of shortages of electricity. Some districts are forced to regularly employ rolling black outs to spread meager electricity supplies across the wide-ranging electrical grids.

Of course, air conditioning often takes the blame for shortages in the hot months and perhaps rightly so. In the era of cheap and abundant electrical energy, few of us cared about the level of insulation in our homes and buildings, in fact, the science of the building envelope was still in its infancy then.

We now know that minimizing heat transfer into and out of our buildings is the best way to conserve energy. The second-best way is to ensure our HVAC equipment is operating and maintained in order to maximize efficiency at or near the optimal design levels.

The Measure of a Machine

One guiding orthodoxy in business is the maxim: “What is not measured cannot be improved.”

The HVAC/R industry has used a measure of refrigerating machine efficiency known as the energy efficiency ratio (EER). EER means the ratio of the average rate of space cooling produced to the average rate of electrical energy consumed by the heat pump or cooling unit.

Efficiency testing is done under standard conditions in a laboratory using rules set by ASHRAE.

EER is expressed in units of Btuh divided by Watts. Suppose a split system air conditioner rated at 3 tons has an average net cooling effect of 34,500 Btuh and the average net power consumption is 3,200 Watts, thus:

EER = 34,500/3,200 = 10.8 Btuh/Watt

Even so, EER provides only a snapshot of the actual conditions that might occur during the cooling season in any given climate region of North America.

The Seasonal Energy Efficiency Ratio (SEER) was implemented in 1992 by the DOE. These standards set minimum energy efficiency requirements for central air conditioning and heat pump equipment sold within Canada and the U.S.

The Air Conditioning, Heating, and Refrigeration Institute (AHRI) developed the SEER method in response to energy-related policies decreed in the 1970’s.

In the 1990s, most cooling units had a SEER rating of 8 or 9. The Energy Policy Act of 2005 enforced upgrades to a minimum SEER of 13. So, the SEER rating has been around for a few decades and has been gradually updated to reflect advances in technology and energy efficiency standards.

The SEER standard led to efficiency improvements, but many high SEER equipment owners did not notice enough of an appreciable benefit from their investment in a considerably more expensive cooling unit or heat pump advertised to reduce their hydro bills.

While there may be a shopping list of poor performance reasons related to the specification, installation and maintenance of said units, a problem with the test method became understood as engineers examined the test parameters for fan-coil systems.

SEER is the ratio of the cooling output of an air conditioner over a typical cooling season, divided by the energy it uses in Watt-Hours.

A SEER ratio is calculated over an entire cooling season using a constant indoor temperature and a variety of outdoor temperatures ranging from 60F to more than 100F.

The new SEER2, on the other hand, includes the total heat removed from the conditioned space during the annual cooling season, using the new M1 testing procedure that increases the external static pressure from 0.1-in. w.c. to 0.5-in. w.c. when applied to ducted fan coil systems.

The original SEER test procedure for fan coil units incorporated an unrealistic duct static pressure almost never found in the typical residential application. Because a heat pump spends around half its life in cooling mode, the M1 standard means heat pump performance must purposely improve as well.

The DOE changed “SEER” to “SEER2” to accommodate new product regulations that went into effect on January 1, 2023.

These changes were made to align more closely with ongoing efforts to reduce overall energy consumption. Using compiled test data, SEER2 is calculated using this formula:

SEER2 = (1 × EER100% + 42 × EER75% + 45 × EER50% + 12 × EER25%) / 100

Where: EER100%, EER75%, EER50%, EER25% represents the Energy Efficiency Ratio at 100%, 75%, 50%, and 25% load, respectively.

And the numbers 1, 42, 45, and 12 represent the percentage of time the unit is expected to operate at each corresponding load.

This equation considers the energy efficiency of a cooling unit at distinct levels of operation, providing a more realistic measure of its overall energy efficiency.

What About Heat Pumps?

The Heating Seasonal Performance Factor (HSPF) standard was part of the National Appliance Energy Conservation Act of 1987. Since 1992, the Federal energy conservation standards for central air conditioners were set at a minimum of 10 SEER and 6.8 HSPF for split system air conditioners and heat pumps.

Air source heat pumps have a controversial history in our cold Canadian climate, very rarely performing effectively leading to most consumers in many parts of our country favouring a higher efficiency gas furnace combined with a high SEER air conditioner.

Another metric often quoted by heat pump enthusiasts is COP, or Coefficient of Performance. COP is a basic measure of a heat pump’s performance under static test conditions. It is calculated by dividing the heat output by the electrical power input. COP is now calculated using the M1 criteria which requires the same more rigorous test conditions prescribed by CAN/CSA-C656-14/10 C.F.R. Appendix M1 (M1 for short).

This new approach will provide a more realistic measure of a heat pump’s true energy efficiency. Therefore, a heat pump with a higher M1 COP, especially at low temperature, is a more energy efficient system.

The DOE tests of heat pumps using the Appendix M1 prescribed 0.5-in. external static pressure test condition for ducted fan coils units show that a system previously rated at 10 HSPF, for example, would suffer a 15% rating reduction to 8.5 HSPF2.

Prior to January 1, 2023, heat pumps sold in Canada under the CSA Standard C656.14 Performance Standard had the AHRI Region IV HSPF adjusted using this formula: Region V = Region IV divided by 1.15.

Thus, a heat pump rated at 9.0 HSPF in Region IV realized an HSPF of 7.8 in Region V which includes most of the populated areas of Canada.

The Government of Canada’s Amendment 17 to our Energy Efficiency Regulations published on December 21, 2022, imposed the following SEER2 energy performance standards on single-phase split system air conditioners and heat pumps under 65,000 Btu/h:

  • Split-system central air conditioners, other than those that are space-constrained or small-duct and high-velocity: SEER2 ≥ 13.4 and off mode power consumption ≤ 30 W.
  • Split system central heat pumps, other than those that are small-duct and high-velocity or space-constrained: SEER2 ≥ 14.3 and HSPF2 (Region V) ≥ 6.0, and Off mode power consumption ≤ 33 W.

SEER2 and HSPF2 became part of our HVAC landscape on January 1, 2023. Figure 1 (below) is an example I copied from the AHRI Directory describing ratings associated with a 20 SEER 3-ton heat pump using a variable speed gas furnace indoors prior to January 1, 2023. HSPF rated at 9.5 Region IV translates to 9.5/1.15 = 8.3 Region V.

Figure 1. Ratings associated with a 20 SEER 3-ton heat pump.

Figure 2 (below) tells the SEER2 and HSPF2 story for the identical system.

Figure 2. The new SEER2 and HSPF2 ratings for the same system as Figure 1.

Note the cooling capacity, heating capacity and HSPF2 are lower. The HSPF2 now at 8.0 continues to be reported as Region IV, thus 8.0/1.15 = 6.9 Region V exceeding the Amendment 17 HSPF2 requirement of 6.0.

Natural Resources Canada (NRCan) is considering making the optional 5F (-15C) test point in the DOE test procedure mandatory in Canadian regulations to better reflect operating conditions in Canada.

Where do consumers stand?

As for the cost, SEER2 units will likely be more expensive upfront however they can lead to significant energy savings overall, which offsets the higher cost.

Homeowners looking for the least expensive complete HVAC system retrofit will benefit by installing the new minimum efficiency 95% AFUE gas furnace connected to a 13.4 SEER2 (formerly 14 SEER) air conditioner. Manufacturers claim a 13.4 SEER2 AC unit can save up to 25% in energy cost per year

On the other hand, a cold climate heat pump sporting an HSPF2 of 7 or better (Region V) matched with a 98% AFUE gas furnace and subsidized by all available government/utility rebates would be my choice for any ducted system owner to consider.

Variable speed mini- and multi-split heat pumps boast SEER2 ratings north of 30 and HSPF2 numbers better than 9 (Region V). No doubt about it, today’s products perform better than ever. <>

Ian McTeer is an HVAC consultant with over 35 years of experience. He was most recently a field rep for Trane Canada DSO. McTeer is a refrigeration mechanic and Class 1 Gas technician. Contact Ian at imcteer@outlook.com.

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