Energy efficiency measures - Residential - House - Energy efficient / Canada

Template assignment

A typical house (base case) is compared with an energy efficient house (proposed case). The building is located in Regina, Saskatchewan, Canada.

Base Case

Fuels & schedules

• Electricity rate is $0.094/kWh, natural gas rate is $0.39/m³
• House is occupied 50% of the time during the week and 75% of the time during the weekend
• Space heating temperature is 21ºC
• Heating/cooling changeover temperature is 16ºC
• No cooling system

Heating system

• Space heating provided by natural gas fired forced air furnace with a seasonal efficiency of 72%
• Domestic hot water heating provided by naturally aspired natural gas hot water heater with a seasonal efficiency of 72%

Building envelope

• North wall building is oriented 26º west of north
• Building envelope components areas:
  • Walls above grade: north and south are 36 m² and east and west are 48 m²
  • Doors: north and east are both 1.7 m²
  • Roof: 218 m²
  • Walls below-grade: 155 m²
  • Floor below-grade: perimeter is 65 m
• Building envelope properties:
  • Walls above grade thermal resistance is 3 m²-ºC/W
  • Doors thermal resistance is 0.8 m²-ºC/W
  • Roof is attic type with a thermal resistance of 5.6 m²-ºC/W
  • Walls below grade thermal resistance is 4 m²-ºC/W
  • Floor below grade is uninsulated
• Windows properties:

• House volume is 935 m³, the building air change rate is 0.6 ac/h

Ventilation

• No active ventilation system

Lights

• Incandescent lamps are used for lighting
• There are 22 fixtures, 60 W, used for an equivalent of 800 h/yr

Electrical equipment

• All the appliances are assumed to be standard
• Appliances and equipment characteristics:

Hot water

• Domestic hot water usage is 225 L/d at 55ºC

Proposed case

Fuels & schedules

• The setback space heating temperature is 2ºC during unoccupied periods

Heating system

• Space heating provided by electric resistance forced air furnace with 100% efficiency (savings of about $200 due to the elimination of natural gas connection + $12.50/month in O&M savings for gas connection monthly charge)
• Domestic hot water heating provided by a tankless electric hot water heater with an efficiency of 100% (incremental cost is $500 + $10/month in O&M savings for tank rental)

Building envelope

• Building envelope properties:
  • Walls thermal resistance is 6.2 m²-ºC/W (incremental cost is $6,500), layers are:
    • Insulated brick (insulated thin brick panel having a thermal resistance of 2.1 m²-ºC/W which is made up of a combination of plywood sheathing, polyurethane insulation and 12 mm fired clay thin brick)
    • Building paper
    • 114 mm structural insulated panel
    • 12.5 mm gypsum wall board
  • Doors thermal resistance is 2.2 m²-ºC/W (incremental cost is $400)
  • Roof with blown cellulose and its thermal resistance is
    14.1 m²-ºC/W (incremental cost is $3,000)
  • Walls below-grade thermal resistance is 6.7 m²-ºC/W (incremental cost is $1,000)
  • Floor below-grade is insulated (incremental cost is $875)
• Windows properties:
  • North, east and west windows are triple, low-e and argon filled
  • South windows are double, low-e and argon filled
  • Incremental cost is $3,150

• The building air change rate is 0.1 ac/h

Ventilation

• Active ventilation system is required (incremental cost is $1,500)
• Central ventilation supply rate is estimated at 30 L/s, 100% fresh air
• Heat recovery ventilator seasonal efficiency is 85%

Lighting

• 15 W compact fluorescent light bulbs are used
• 22 fixtures, 800 h/yr
• Incremental cost is $3/fixture and O&M savings are of $2.5/fixture

Electrical equipment

• EnergyStar appliances are used for the refrigerator, freezer, clothes washer, dishwasher and miscellaneous outdoor and indoor electrical loads
• Appliances and equipment characteristics:

Hot water

• Domestic hot water load is reduced to 150 L/d with the front load clothes washer, EnergyStar dishwasher, two low-flow shower heads (incremental cost is $65 each)
• Drainwater heat recovery unit recovers approximately 30% of the heat (incremental cost is $600)

Incentives

• A $1,000 rebate is obtained for the purchase of an EnergyStar qualified home
• A $150 rebate is obtained for the purchase and installation of the drainwater heat recovery unit

Solution

The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.

Similar project

The Factor 9 Home project involves the design, construction, monitoring and technology transfer of a demonstration home built in Regina, Saskatchewan, Canada. The house was completed in April 2007 and was named Factor 9 since it is projected to use 9 times less energy than a conventional 1970 Saskatchewan house of the same size. This low-energy consumption is achieved with a building envelope with high thermal resistance, an airtight construction, energy efficient lighting and appliances, active and passive solar heating, as well as air and water waste heat recovery. In addition, the Factor 9 Home features several water use reduction measures such as low-flow appliances, low water use landscaping and roof water collection that are expected to reduce the house water consumption by a factor of 2 compared to a conventional home. As a result, the Factor 9 Home is a demonstration of a low-impact healthy house that reaches a higher level of energy performance.

The house characteristics of this case study are based on the Factor 9 Home, but not all the features of this house are included (e.g. solar water heater).

Real project - Website
Real project (119 KB)