Shout out to Mike DuClos and Jonathan Kantor for much appreciated assistance. All remaining errors are mine.

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1 Heat Pumps

2 Shout out to Mike DuClos and Jonathan Kantor for much appreciated assistance. All remaining errors are mine.

3 What Is a Heat Pump (HP)? Technically, it is an application of the Carnot cycle (engine) Carnot cycle transfers energy from one source to another Air conditioner transfers heat from inside your house to outside Refrigerator removes energy from inside refrigerator (and transfers it to your kitchen) to cool its contents Freezer maintains its nearly zero temperature all year round The link below is for the techies 3

4 Why Are We Interested in Heat Pumps? A new generation of [air source] HPs utilizing inverter-driven, variable-speed compressors has come to market over the past five years. These systems have demonstrated radically improved heating performance under low temperature conditions (near or below 5 F), while continuing to offer highly efficient cooling. from Northeast Energy Efficiency Partnerships. (2017, January). Northeast/Mid-Atlantic air-source heat pump market strategies report 2016 update. Lexington, MA: Author. For example, both Mitsubishi and Fujitsu claim that they can achieve 60% of capacity at -15 deg. F. Other make similar claims. Bottom line: Cold climate air source HPs may be sufficient and economic for all of your heating and cooling needs if your home is sufficiently sealed and weatherized to lower your current heating requirements. To achieve maximum benefits, it s worth having a quality Home Energy Rating System (HERS) assessment performed and have the system carefully installed. (More on this later.) 4

5 HP Coefficient of Performance - COP Electricit y 1 Unit Energy input Heat from/to outside Heat to/from building 3 Units Energy moved Output Energy / Input Energy = COP, here 3 / 1 = 3 Electric resistance heating = 1 / 1 = 1 From ASHP Field Performance Overview, Mass Clean Energy Center, November 15, 2018, Mike Duclos, DEAP Energy Group, LLC

6 COP impact on CO 2 David MacKay Saul Griffith Recalculated 6 From ASHP Field Performance Overview, Mass Clean Energy Center, November 15, 2018, Mike Duclos, DEAP Energy Group,

7 Three Types of Space Conditioning Heat Pumps 1. Ground source (geothermal) HP This is primarily a new construction option Requires installing a ground heat sink generally easier in new construction These systems are ducted and ducting is generally easier in new construction 2. Air Source Heat Pumps Central, ducted heat pumps Ductless mini-splits Ducted mini-splits 3. Air to Water Heat Pumps (very new - we won t discuss here) Sometimes more than one type in a home For example, ductless mini-split HP on first floor, air source ducted on second 7

8 Three Types of Space Conditioning Heat Pumps 1. Ground Source (Geothermal) Heat Pump 8

9 Three Types of Space Conditioning Heat Pumps 2. Central Air Source Ducted Heat Pump System 9

10 Three Types of Space Conditioning Heat Pumps 2. Ductless Mini-split Systems 10

11 Heat Exchanger 1. Air flow - CFM 2. Return air temperature - F 3. Refrigerant temperature - F 4. Supply air temperature - F Blower behind Vanes 11 Air Turning Vanes From ASHP Field Performance Overview, Mass Clean Energy Center, November 15, 2018, Mike Duclos, DEAP Energy Group, LLC

12 Lineset connects outdoor, indoor units Refrigerant Lines Electricity Condensate Drain From ASHP Field Performance Overview, Mass Clean Energy Center, November 15, 2018, Mike Duclos, DEAP Energy Group, LLC

13 Three Types of Space Conditioning Heat Pumps 2. Ducted Mini-split Systems From ASHP Field Performance Overview, Mass Clean Energy Center, November 15, 2018, Mike Duclos, DEAP Energy Group, LLC

14 Sometimes more than one type in a home For example, ductless mini-split HP on first floor, air source ducted on second 14

15 There Are Also Heat Pump Water Heaters 15

16 Advantages of Heat Pumps They do not use natural gas They are controllable They allow for easy zoning Mostly Set it and forget it Can set different temperature ranges for different times of the day and week for rooms where there is an air handler, though you probably don t want the range too wide. These systems are best at maintaining a consistent temperature Heat pumps provide both heating and cooling efficiently Ductless systems often have better efficiency than ducted systems because of reduced losses from ducting Many can be monitored and controlled remotely through your home s WiFi system Systems can send alerts to phone if not meeting setpoints Can modify system operations through your mobile phone 16

17 If You re Interested in Installing a Heat Pump (1) Heat pumps provide the greatest heating benefit if you ve installed insulation and have made sure your home is relatively well-sealed So, the first step is making sure you ve done what you can to insulate and tighten up your home thermally Have a home energy audit done. Both Eversource and National Grid are sponsoring them. You should do this anyway even if you don t put in a heat pump MassSave is having an end-of-year special MassSave is also offering rebates on heat pumps 17

18 If You re Interested in Installing a Heat Pump (1a) You may want to consider installing a heat pump if - you ve thought about installing central air conditioning particularly if you have lots of window units in your home like this one 18

19 If You re Interested in Installing a Heat Pump (1b) You may be also interested if you have a special situation, such as a newly renovated attic or basement and don t have adequate space heating/cooling in these areas. 19

20 If You re Interested in Installing a Heat Pump (2) If you re home is well-insulated and thermally sealed, then the next question is: Does my electrical system have sufficient capability to accommodate the new electrical loads? The capability of your home to support its electrical needs is determined by the size of the electrical panel/service inside your home that connects you to Eversource Older homes relying on natural gas for space and water heating often have 100 Amp panels Depending on the sizing of the heat pump, many require a minimum panel size of 200 Amps. Changing the panel requires an electrical contractor. If you decide to put in a heat pump but don t have a large enough panel, that will be an additional cost. 20

21 If You re Interested in Installing a Heat Pump (3) If you re home is well-insulated and you can add a heat pump system, then the next question is: What kind of heat pump do I want? For smaller homes without existing ductwork, the ductless mini-split heat pump is most likely what you want. Ducted systems are also an option, but will require giving up space somewhere attic, crawl space, etc. which is sometimes at a premium for smaller homes. Need to make sure those spaces for the ductwork are conditioned. A contractor will go over your heating and cooling requirements with you to determine the number of compressor units and their size (the equipment outside of your home), the number of air handlers and their size (the units inside your home) and the locations of all of them. Mitsubishi, Fujitsu, Daikin, Friedrichs, etc. have lots of options. You need to make sure that your system is designed for our colder New England winters. 21

22 If You re Interested in Installing a Heat Pump (3) For larger homes with existing ductwork, then one of the ducted heat pump systems could be a potential choice. Your current ducting may work, but it may not. 22

23 If You re Interested in Installing a Heat Pump (4) Regardless of which system you choose, you will need to rely on a contractor for assistance. When we design, install, operate ASHP incorrectly, they do not perform to their potential. Mike DuClos, DEAP Energy Group Based on Mike Duclos s 1 presentation at MassCEC, need to be careful about sizing, placing, and installing equipment. It s best if a contractor performs a room by room assessment based on HERS Manual J heat load calculations and uses HERS Manual S sizing to select equipment. Most HVAC contractors don t, so they may charge additionally for it, but it is likely to be worth it. Link to sample report advanced_class_reports.pdf Contratctors MassSave has a program which educates contractors on the ins and outs of installing heat pumps, although that is not a guarantee of the quality of the assistance. Although the website says it is for central units, I was told they also include mini-split training. Mitsubishi has a Diamond certification for its qualified installers. Again, not a guarantee about the quality of the work, but it comes with guarantees I haven t been able to find from the other manufacturers ASHP Field Performance Overview, Mass Clean Energy Center, November 15, 2018, Mike Duclos, DEAP Energy Group, LLC

24 Outdoor Unit 24 From Getting the Most from Air-Source Heat Pumps, North American Passive House C onference Boston, September 2018, Robb Aldrich, Steven Winter Associates,

25 Outdoor Unit 25 From Getting the Most from Air-Source Heat Pumps, North American Passive House C onference Boston, September 2018, Robb Aldrich, Steven Winter Associates,

26 Installation Considerations Locate indoor unit Locate outdoor unit Pay attention to water/ice/ snow Pay attention to line set lengths Make good connections Triple evacuation/purge with nitrogen to remove ice created during evacuation, followed by leak test Charge properly! From Getting the Most from Air-Source Heat 26 Pumps, North American Passive House C onference Boston, September 2018, Robb Aldrich, Steven Winter

27 Conclusions Heat pumps can be an environmentally friendly way of heating and cooling your homes In the long run, electrification of our energy uses appears to be the best way to address global climate change The quality of the installation is crucial to achieving the energy savings. HERS assessment of weatherization of your home is a useful first step. Use a contractor with heat pump experience. Help in paying for HPs MassSave is having an end-of-year special on weatherization MassSave is also offering rebates on heat pumps 27

28 28 Questions?

29 Appendix

30 Basic Heat Pump Operation 30 (INVERTER) From Getting the Most from Air-Source Heat Pumps, North American Passive House C onference Boston, September 2018, Robb Aldrich, Steven Winter Associates, Inc.