Air Source Heat Pumps - Their Performance, Issues and Potential in the North

Transcription

1 Air Source Heat Pumps - Their Performance, Issues and Potential in the North Doug Cane Principal Caneta Research Inc Northern Energy Solutions Conference February 16, 2010

2 Scope of Presentation Use of air source heat pumps in Northern climates. Do s and don ts of heat pump installations. What the latest cold climate designs have to offer in terms of performance. Compare climate of Whitehorse to that of Ottawa. Cost benefit results for latest cold climate designs in residential applications in Whitehorse will be presented. conclude by identifying the advantages and drawbacks of such systems.

3 Dos and Don ts of Heat Pump Installation Heat pump installation can be divided into: Outdoor unit Indoor unit System start-up/turnover Homeowner instruction

4 Outdoor Unit Location of Outdoor Unit: site unit where prevailing winds will not cause snow drifts or interfere with defrosting. avoid locations between houses - snow drifting and noise can be problems. locate unit to ensure good service access. don t locate under roof drip lines or where two roof slopes create gutter, unless eave-troughs are used

5 Outdoor Unit

6 Outdoor Unit

7 Outdoor Unit

8 Outdoor Unit

9 Outdoor Unit

10 Outdoor Unit elevate above expected snow accumulations on suitably constructed frame with due regard to defrost water drainage. keep outside unit away from walls, fences, other surfaces which could reduce airflow or cause recirculation.

11 Outdoor Unit

12 Outdoor Unit

13 Indoor Unit Installation use indoor coil that matches outdoor unit and furnace blower CFM capability. set airflow to 400 CFM per rated ton. install condensate drain for indoor coil that complies with manufacturer and local codes. ensure air filter is installed and clean. tape or seal all exposed plenum, air duct joints, seams and any penetrations to minimize supply air leakage.

14 System Start-up and Turnover system start-up shall be done in strict accordance with procedures recommended by manufacturer. heat pump should have comprehensive instructions, and documentation on equipment installation, electrical requirements, troubleshooting, O&M requirements, warranty (duration, parts and labour coverage). contractor should keep installation records to facilitate future servicing; respond to warranty claims and rectify problems without delay.

15 Homeowner Instructions make purchaser aware of benefits of upgrading building insulation/windows etc. to meet or exceed current Yukon requirements. turn over documentation to homeowner and instruct on differences from other heating systems, settings of thermostats, proper service and maintenance, and how to operate thermostats (including programming where applicable).

16 Examples of Cold Climate Designs Acadia York YZH Mitsubishi Mr Slim

17 Acadia

18 Acadia Features Two compressors - Bristol Twin Single and booster compressor HSPF: 9.33; COP@17ºF: 2.5; COP@0ºF: 2.3 Heating Capacity@17ºF: 43,500 Btu/hr Heating Capacity@0ºF: 35,000 Btu/hr six modes of operation are possible

19 York YZH

20 York YZH Features One of most efficient units in AHRI Directory HSPF: 10.0; SEER: 18.0; 17ºF: 3.0; 10ºF: 2.7 Heating Capacity: 22,500 17ºF; 19,300 10ºF Twin Single Compressor (1 and 2 cylinder operation) Microprocessor controls with demand defrost matched to variable-speed (ECM) air handler or furnace

21 Mitsubishi Mr Slim

22 Mitsubishi Features 17 ºF: 2.4; 0ºF: 2.0 the 2 ton unit has a heating capacity of 14,540 17ºF and 8,930 0ºF

23 COP and Heating Capacity vs Outdoor Temperature for Acadia Heat Pump COP Outdoor Temperature ( F) Heating Capacity (kbtu/h) COP Cold Climate Heating Capacity Cold Climate

24 COP and Heating Capacity vs Outdoor Temperature for York YZH COP Outdoor Temperature ( F) Heating Capacity (kbtu/h) COP Conventional Heating Capacity Conventional

25 COP and Heating Capacity vs Outdoor Temperature for Mitsubishi Mr Slim COP Heating Capacity (kbtu/h) Outdoor Temperature ( F) COP Mini Split Heating Capacity Mini Split

26 Comparison of Ottawa and Whitehorse Weather Data Number of Hours at Temperature Trendline for Whitehorse Data Outdoor Air Drybulb Temperature ( F) Trendline for Ottawa Data

27 Yukon Energy Prices Electricity: 12.4 /kwh Heating Oil: $1.07/litre (Dawson) Heating Oil: $1.01/litre (Whitehorse)

28 Base Case Annual Heating Costs 1800 ft 2 Oil Furnace - SuperGreen: $2,596 Oil Furnace - 2x4: $5,524

29 Heat Pump Installed Costs Acadia - 3 ton: $20,100 York YZH - 4 ton: $11,075 Mitsubishi ton: $5,665

30 Acadia Payback Compared to Oil 35 Simple Payback (years) ,000 4,000 6,000 8,000 10,000 Heating Energy Cost Per Year 2 ton 3 ton 4 ton

31 York Payback Compared to Oil Simple Payback (years) ton 4 ton 5 ton 0 2,000 4,000 6,000 8,000 10,000 Heating Energy Cost Per Year

32 Mitsubishi Payback Compared to Oil 16 Simple Payback (years) ton 1.5 ton 2.0 ton 0 2,000 4,000 6,000 8,000 10,000 Heating Energy Cost Per Year

33 Conclusions Cold climate designs promise more heating capacity and higher efficiency at low temperatures. Payback periods look attractive at higher levels of consumption. Longer hours of operation may impact on reliability and compressor life. More operating experience is needed. Limited number of cold climate designs at present.