Proposed Change 1836

The National Building Code of Canada (NBC) does not currently assign energy conservation points to gas-fired furnaces in the prescriptive trade-off path in Section 9.36. This proposed change would establish the number of energy conservation points assigned to gas-fired furnaces with performance levels that exceed the minimum performance required by Energy Performance Tier 1.

Failure to assign energy conservation points to gas-fired furnaces as specified would prevent Code users from accumulating the energy conservation points associated with the energy savings gained from installing a high-efficiency gas-fired furnace, unless the performance compliance path is used.

In order to accumulate energy conservation points for higher performance tiers, more options in terms of energy conservation measures are required than are currently provided in the Code.

The choice of gas-fired furnace contributes to a building's energy savings. Code users who choose to install high-efficiency gas-fired furnaces will benefit from the additional energy savings provided by the equipment when complying with the prescriptive trade-off path in Section 9.36.

By assigning energy conservation points to gas-fired furnaces exceeding the minimum performance required for Tier 1, Code users would benefit from this additional option for demonstrating compliance with a higher energy performance tier in the prescriptive trade-off path.

Additionally, this proposed change adds granularity for energy conservation points provided in tabulated form for gas-fired furnaces by allowing interpolation. If this proposed change did not permit interpolation, Code users would only be able to claim the lower of two point values when the minimum performance of the chosen gas-fired furnace falls between two values listed in proposed NBC Table 9.36.8.9.

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

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 gas-fired furnace.

Upgrading to higher efficiency gas-fired furnace does not result in substantial increase in energy savings relative to the increase in incremental cost of equipment. When choosing to install a higher efficiency gas-fired furnace, 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.

As demonstrated by Table 1., Code users who choose to install higher efficiency gas furnaces would be credited with between 0.4 and 1.6 energy conservation points, which represents the percentage energy savings, and would incur a cost of between $1,124 and $2,120.

Table 1. Comparison of Costs and Energy Savings of Gas-Fired Furnaces by Region

Source: furnacestore.ca; prices listed include retail markup and Canada-wide free shipping.

Notes to Table 1.:

(1) AFUE = annual fuel utilization efficiency

(2) Equipment used was the Goodman Gas Furnace – Upflow, Modulating Variable Speed and 60,000 BTU / 3 Ton Blower.

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

Designers, engineers, architects, builders and building officials.