4 Storey Wood Frame Apartment Building
20-40 years old
Building Overview
- Four storey wood frame multi-unit residential building (common in the BC Lower Mainland)
- Copper piping for domestic hot water. There is a re-circulation pump on the hot water system, which is controlled by an aquastat, so that the supply and return temperatures remain relatively constant (leaving water temp = 60ºC, entering water temp = 50ºC).
- The heat flux from the domestic water piping contributes to space heating during winter months
- Heat source: direct fired gas water heaters with a nameplate efficiency of 80%
- Indoor design temperature: 20ºC
- Heating season: September 15 to May 15 (8 months)
- Gas cost: $9.486/GJ • Service life: 20 years
- Building conditioned floor space: approx. 45,000 square feet (4,200 square metres)
Modeled Scenarios:
1. No insulation on hot water pipes
2. 25mm thick insulation on hot water pipes
Results:
Over the course of one year the following savings would result from the use of insulation.
ANNUAL ENERGY AND GREENHOUSE GAS SAVINGS
| Resource | Annual Reduction |
|---|---|
| Energy Saved (kWh) | 45,802 |
| GHG Emissions C02e (tonnes) | 8.4 |
The following table summarizes the impact on overall building energy consumption.
| Total Energy Consumption | 726,600 kWh |
|---|---|
| Energy savings due to pipe insulation | 45,802 kWh or 6.3% of total consumption |
The estimated payback for the investment in insulation during construction would be less than 4.0 years based solely on the energy costs.