Page: Last modified: 2024-02-15
Code Reference(s):
NBC20 Div.B 9.36.8.9. (first printing)
Subject:
Prescriptive Trade-off Path
Title:
Energy Conservation Points for Air-Source Heat Pumps
Description:
This proposed change assigns energy conservation points to air-source heat pumps for compliance with the Prescriptive Trade-off Path in Section 9.36.
This change could potentially affect the following topic areas:

Problem

The National Building Code of Canada (NBC) does not currently assign energy conservation points to air-source heat pumps in the prescriptive trade-off path of Section 9.36. This proposed change would establish the number of energy conservation points assigned to air-source heat pumps for various heating load capacity and equipment efficiencies.

Failure to assign energy conservation points to air-source heat pumps would not allow Code users to obtain energy conservation points associated with the energy savings from installing a high-efficiency air-source heat pump unless they use the performance compliance path.

In order to accumulate the total number of energy conservation points required to demonstrate compliance with higher tiers, Code users should have additional options for energy conservation measures than those currently provided in the Code.

Justification

Choice of an air-source heat pump contributes to energy savings in a building. Code users who choose to install a high-efficiency air-source heat pump will benefit from the additional energy savings provided by the equipment when complying with the prescriptive trade-off path in Section 9.36.

If energy conservation points are assigned to air-source heat pumps, Code users will benefit from this additional option for demonstrating compliance with a higher energy performance tier in the prescriptive trade-off path.

Failure to add additional energy conservation measures might prevent Code users from accumulating sufficient points to comply with higher tiers, as required by their respective jurisdictions.

PROPOSED CHANGE

[9.36.8.9.] 9.36.8.9.Energy Conservation Measures for HVAC Systems

[1] 1)HVAC systems, equipment and installations shall be designed and constructed in accordance with Articles 9.36.3.2. to 9.36.3.8. and this Article.
[2] 2)Where HVAC systems, equipment or techniques other than those described in Articles 9.36.3.2. to 9.36.3.8. and this Article are used, the building shall be designed and constructed in accordance with the NECB.
[3] 3)Ventilation systems serving buildings to which this Subsection applies shall be equipped with a heat-recovery ventilator conforming to Article 9.36.3.9.
[4] 4)Heat-recovery ventilators that comply with one of the energy conservation measures prescribed in Table 9.36.8.9. shall be credited with the corresponding energy conservation points stipulated therein.
Table [9.36.8.9.-A] 9.36.8.9.
Energy Conservation Measures and Points for Ventilation Systems
Forming Part of Sentence [9.36.8.9.] 9.36.8.9.([4] 4)
Energy Conservation Measures for Ventilation Systems – Sensible Heat-Recovery Efficiency, SREPROPOSED CHANGE Table 9.36.8.9. Footnote (1) Heating Degree-Days of Building Location, in Celsius Degree-Days
Zone 4
< 3000
Zone 5
3000 to 3999
Zone 6
4000 to 4999
Zone 7A
5000 to 5999
Zone 7B
6000 to 6999
Zone 8
≥ 7000
Energy Conservation Points
60% ≤ SRE < 65% 0.7 0.7 0.7 0.6 0.8 0.4
65% ≤ SRE < 75% 2.1 2.1 2.2 1.7 2.3 1.2
75% ≤ SRE < 84% 3.4 3.2 3.5 2.7 3.7 1.8
[5] --)Except as provided in Sentence (6), air-source heat pumps shall be credited with
[a] --)where the air-source heat pump complies with one of the energy conservation measures prescribed therein, the corresponding energy conservation points stipulated in Table 9.36.8.9.-B, or
[b] --)the energy conservation points calculated using the appropriate equation set out in Table 9.36.8.9.-C, provided the air-source heat pump has
[i] --)a fraction of rated capacity at 8.3°C to required capacity of heating appliances determined in accordance with Sentence 9.33.5.1.(1) that is greater than or equal to 60% and less than or equal to 100%, and
[ii] --)a heating seasonal performance factor for region V of greater than or equal to 5.2 (Btu/h)/W.
Table [9.36.8.9.-B]
Energy Conservation Measures and Points for Air-Source Heat Pumps Described in Clause 9.36.8.9.(5)(a)
Forming Part of Clause 9.36.8.9.(5)(a)
Energy Conservation Measures for Air Source Heat Pumps – Heating Seasonal Performance Factor 2 for Region V, HSPF2 VPROPOSED CHANGE Table Footnote (1) Minimum Air Source Heat Pump Capacity/Load FractionPROPOSED CHANGE Table Footnote (2) Heating Degree-Days of Building Location, in Celsius Degree-Days
Zone 4
< 3000
Zone 5
3000 to 3999
Zone 6
4000 to 4999
Zone 7A
5000 to 5999
Zone 7B
6000 to 6999
Zone 8
≥ 7000
Energy Conservation Points
5.2 60% 28.6 22.9 20.5 18.4 19.9 10.7
6.7 30.8 25.3 22.9 20.6 22.2 12.3
7.6 32.1 26.8 24.4 22.0 23.6 13.3
8.3 33.1 28.0 25.6 23.0 24.7 14.0
9.6 35.0 30.1 27.7 24.9 26.7 15.4
Table [9.36.8.9.-C]
Calculation of Energy Conservation Points for Air-Source Heat Pumps in Accordance with Clause 9.36.8.9.(5)(b)
Forming Part of Clause 9.36.8.9.(5)(b)
Heating Degree-Days of Building Location, in Celsius Degree-Days
Zone 4
< 3000
Zone 5
3000 to 3999
Zone 6
4000 to 4999
Zone 7A
5000 to 5999
Zone 7B
6000 to 6999
Zone 8
≥ 7000
Energy Conservation PointsPROPOSED CHANGE Table Footnote (1)
17.7 + (0.0647 F) + (1.46 HSPF2 V) 2.4+(0.198 F) + (1.65 HSPF2 V) (0.198 F) + (1.65 HSPF2 V) (0.180 F) + (1.47 HSPF2 V) 3.0+(0.147 F) + (1.55 HSPF2 V) −4.7 + (0.165 F) + (1.06 HSPF2 V)
[6] --)Air-source heat pumps shall be credited with energy conservation points in accordance with Sentence (7), provided the air-source heat pump has
[a] --)a rated coefficient of performance greater than or equal to 1.8 at −15°C, and
[b] --)a rated capacity at −15°C that is greater than or equal to 70% of its rated capacity at 8.3°C.
[7] --)Air-source heat pumps described in Sentence (6) shall be credited with the corresponding energy conservation points
[a] --)prescribed in Table 9.36.8.9.-D, provided the air-source heat pump complies with one of the energy conservation measures, or
[b] --)calculated using the equations in Table 9.36.8.9.-E, provided the air-source heat pump has
[i] --)a fraction of rated capacity at 8.3°C to required capacity of heating appliances determined in accordance with Sentence 9.33.5.1.(1) greater than or equal to 60% and less than or equal to 120%, and
[ii] --)a HPSF V of greater than or equal to 6.7 (Btu/h)/W.
Table [9.36.8.9.-D]
Energy Conservation Measures and Points for Air-Source Heat Pumps Described in Clause 9.36.8.9.(7)(b)
Forming Part of Clause 9.36.8.9.(7)(b)
Energy Conservation Measures for Air Source Heat Pumps – Heating Seasonal Performance Factor 2 for Region V, HSPF2 VPROPOSED CHANGE Table Footnote (1) Minimum Air Source Heat Pump Capacity/Load FractionPROPOSED CHANGE Table Footnote (2) Heating Degree-Days of Building Location, in Celsius Degree-Days
Zone 4
< 3000
Zone 5
3000 to 3999
Zone 6
4000 to 4999
Zone 7A
5000 to 5999
Zone 7B
6000 to 6999
Zone 8
≥ 7000
Energy Conservation Points
6.7 60% 33.8 34.2 31.3 29.5 28.5 19.6
7.6 35.2 36.2 33.2 31.4 30.3 21.0
8.3 36.3 37.7 34.8 32.9 31.6 22.1
9.6 38.3 40.5 37.6 35.5 34.2 24.2
Table [9.36.8.9.-E]
Calculation of Energy Conservation Points for Air-Source Heat Pumps in Accordance with Clause 9.36.8.9.(7)(b)
Forming Part of Clause 9.36.8.9.(7)(b)
Heating Degree-Days of Building Location, in Celsius Degree-Days
Zone 4
< 3000
Zone 5
3000 to 3999
Zone 6
4000 to 4999
Zone 7A
5000 to 5999
Zone 7B
6000 to 6999
Zone 8
≥ 7000
Energy Conservation PointsPROPOSED CHANGE Table Footnote (1)
22.5 + (0.0112 F) + (1.58 HSPF2 V) 16.6 + (0.0523 F) + (2.16 HSPF2 V) 12.8 + (0.0657 F) + (2.17 HSPF2 V) 12.4 + (0.0546 F) + (2.07 HSPF2 V) 13.1 + (0.0338 F) + (1.99 HSPF2 V) 6.8 + (0.0397 F) + (1.56 HSPF2 V)

Impact analysis

This proposed change would improve the affordability of complying with the energy performance tiers through the prescriptive path by increasing the number of measures eligible for points and allowing Code users to obtain credit for the energy savings associated with installing a high-efficiency air-source heat pump.

Installing higher efficiency air-source heat pump results in substantial increase in energy savings relative to the increase in equipment cost, as shown in Tables 1 and 2. When choosing to install a higher efficiency air-source heat pump, Code users would benefit from receiving the assigned energy conservation points for that equipment to contribute to demonstrating compliance with a higher energy tier of the prescriptive trade-off path.

Table 1. Cost of Regular Air-Source Heat Pumps

HSPF2(1)(2) Energy Savings (%) Cost of Air-Source Heat Pumps ($)
BC AB SK and MB ON QC Atlantic Canada Northern Canada
5.2(a) 10.7–28.6 5,200 5,200 5,200 5,200 5,200 5,200 5,200
6.7(b) 12.3–30.8 5,800 5,800 5,800 5,800 5,800 5,800 5,800
7.6(c) 13.3–32.1 6,806 6,806 6,806 6,806 6,806 6,806 6,806
8.3(d) 14.0–33.1 10,268 10,268 10,268 10,268 10,268 10,268 10,268
9.6(e) 15.4–35.0 12,738 12,738 12,738 12,738 12,738 12,738 12,738

Sources: www.rsl.ca (a), www.hvactrust.ca (d) and (e), www.pickhvac.com/heat-pump/ (b) and (c); prices listed were in effect on July 31, 2023, and do not include installation, taxes or fees.

Notes to Table 1: 
(1) HSPF2 = heating seasonal performance factor 2
(2) Equipment:
(a) Ducane 1.5 ton, single stage, 4HP14B
(b) Carrier Comfort 25HCD3, single-stage
(c) Bryant Legacy 213C, single-stage
(d) Lennox EL22XPV, 2 ton, 24000 BTU
(e) Lennox EL22XPV, 4 ton, 48000 BTU

Table 2. Cost of Cold Climate Air-Source Heat Pumps

HSPF2(1)(2) Energy Savings (%) Cost of Air-Source Heat Pumps ($)
BC AB SK and MB ON QC Atlantic Canada Northern Canada
6.7(a) 19.6–34.2 7,000 7,000 7,000 7,000 7,000 7,000 7,000
7.6(b) 21.0–36.2 17,946 17,946 17,946 17,946 17,946 17,946 17,946
8.3(c) 22.1–37.7 24,008 24,008 24,008 24,008 24,008 24,008 24,008
9.6(d) 24.2–40.5 24,008 24,008 24,008 24,008 24,008 24,008 24,008

Sources: www.rsl.ca (a) and www.1clickheat.com (b), (c) and (d). The prices were in effect on July 31, 2023, and do not include installation, taxes or fees.


Notes to Table 2:
(1) HSPF2 = heating seasonal performance factor 2
(2) Equipment:
(a) Ducane 2.5 ton - 4HP15L
(b) Tosot Apex Central Heat Pumps, TU60-48WADU - TUD48-24AH2ADU – 48000 BTU capacity
(c) and (d) Mitsubishi Zuba Central Hyper Heat Ducted Heat Pump, 24000 BTU capacity

Cold climate air-source heat pumps are generally more expensive than regular air-source heat pumps as they have been technologically improved for application in challenging and harsh climates.

Code users who choose to install regular air-source heat pump would be credited with between 10.7 and 37 energy conservation points, which represents percentage energy savings and would cost between $5,200 and $12,738. Similarly, Code users who choose to install cold climate air-source heat pumps would be credited with between 19.6 and 40.5 energy conservation points for an expense of between $7,000 and $24,000.

Enforcement implications

This proposed change could be enforced using the existing Code enforcement infrastructure.

Who is affected

Designers, engineers, architects, builders and building officials.

OBJECTIVE-BASED ANALYSIS OF NEW OR CHANGED PROVISIONS

[9.36.8.9.] 9.36.8.9. ([1] 1) no attributions
[9.36.8.9.] 9.36.8.9. ([2] 2) no attributions
[9.36.8.9.] 9.36.8.9. ([3] 3) no attributions
[9.36.8.9.] 9.36.8.9. ([3] 3) [F95,F100-OE1.1]
[9.36.8.9.] 9.36.8.9. ([4] 4) [F95-OE1.1]
[9.36.8.9.] -- ([5] --) [F95-OE1.1]
[9.36.8.9.] -- ([6] --) [F95-OE1.1]
[9.36.8.9.] -- ([7] --) [F95-OE1.1]
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