Hot Water a Hot Commodity Better Buildings by Design, February 2012 Burlington, VT

Transcription

1 Hot Water a Hot Commodity Better Buildings by Design, February 2012 Burlington, VT Gary Klein Affiliated International Management, LLC gary@aim4sustainability.com Gary Klein, 2012

2 Efficiency Vermont is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Learning Objectives Gain an understanding of the magnitude and trends of water heating compared to space heating and cooling Learn how a very efficient water heater can be the thermal engine for the space conditioning system Explore the ways to integrate this concept into very efficient houses Identify which products are there today and which are emerging to implement this vision

4 Course Evaluations In order to maintain high quality learning experiences, please access the evaluation for this course by logging into CES Discovery and clicking on the Course Evaluation link on the left side of the page.

5 Has Someone Moved Our Cheese?

6 Energy Pie 1990 Heating and Cooling Water Heating Refrigeration Lighting Clothes Drying Television Computers Vampires Miscellaneous 100 Units of Energy

7 Energy Pie 2010 Heating and Cooling Water Heating Refrigeration Lighting Clothes Drying Television Computers Vampires Miscellaneous 89 Units of Energy

8 Energy Pie 2020 Heating and Cooling Water Heating Refrigeration Lighting Clothes Drying Television Computers Vampires Miscellaneous 45 Units of Energy

9 Annual Energy Use Pattern Peak Base Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

10 Annual Energy Use Pattern Peak Base Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

11 Annual Energy Use Pattern Peak Base Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

12 Combi Systems One Thermal Engine How many days a year do we: 1. Use hot water? 2. Heat the house? 3. Air condition the house? Size of heating peak? Cooling peak? Size of water heating peak? Why are we still so focused on condensing furnaces and not on condensing water heaters that can also heat the house?

13 Combi Systems: Distribution Options Radiant floors, walls, ceilings Hydronic baseboards and radiators Forced air hydronic air handlers Combinations of the above?

14 Hydronic Air Handler Schematic 14

15 Cutaway of Air Handler 15

16 Piping Priority for Hot Water 16

17 Atmospheric Boiler with Side Arm Tank

18 Atmospheric Gas Water Heater

19 Atmospheric Gas Water Heater 50 Gallon 63,000 Btu Where does the make-up air come from? Does the air handler cause the water heater to down draft?

20 Condensing Gas Water Heater Water Heater 55 gallon tank 199,000 Btu Air Handler Heating coil AC coil 18-24,000 Btu

21 Condensing Gas Water Heater Water Heater 50 gallon tank 100,000 Btu Air Handler Heating coil AC coil 18-24,000 Btu

22 Minneapolis 25 year old system

23 Condensing Gas: Integrated System Integrated Design Water heating Space heating Air-to-Air Heat Exchanger

24 Air-to-Water Heat Pump: Integrated System

25 Products Water heaters, boilers, heat pumps, desuperheaters Fan coils Heating only Heating and air conditioning Temperature drop Pressure drop Pumps Controls Integration with air to air heat exchangers

26 What are the Potential Benefits? One thermal engine Highest efficiency for the largest thermal peak and largest energy need High efficiency for small space conditioning loads Sealed combustion and indoor air quality Design and installation flexibility More comfortable. Usually quieter. Simpler? Reduced maintenance costs? Other?

27 What are the Potential Problems? Health and Safety: is a heat exchanger necessary? Sizing: Capacity if heating both water and space? What size air handlers? Will gas water heaters operate in condensing mode? How will efficiency be measured? Which trade(s) will do: Installation Maintenance Other?

28 What are the Markets? High Performance Buildings New Construction Retrofits Energy Star for Homes Green Building Programs Low Income Weatherization Other?

29 Minneapolis The Future is Now! Two Low Income Weatherization Programs 400 homes Weatherize homes first Get below 20 Btu/hour/square foot at peak Combustion safety Install combi-air systems Expecting contractors will settle on certain packages 10% will have air-to-air heat exchangers Process Evaluate systems in a controlled setting Collaborate with contractors and manufacturers on what is needed and what works together Feedback on all aspects in integral to project Concentrated roll-out creates critical mass

30 Special Thanks Sustainable Resources Center Ben Schoenbauer, Minneapolis Center for Energy and the Environment Northern Star Building America Team

31 Storage water heater based system Cold In from Mains DHW Loads Hot Space Heating Air Supply to AH Storage Water Heater Return from AH Hydronic Air Handler Open Loop

32 Tankless water heater based system DHW Loads Cold In from Mains Hot Space Heating Air Supply to AH TWH Return from AH Hydronic Air Handler Electric Gas Electric

33 Combi boiler based system DHW Loads Hot Space Heating Air Cold In from Mains HE DHW Loop Supply to AH Space loop Combi Boiler Return from AH Hydronic Air Handler Primary Loop Secondary Loop Closed Loop

34 Installation and Sizing PROBLEM Some contractor s had little experience System schematics often developed on site Little or no sizing information provided System components came from several manufacturers Manufacturer s settings may not lead to best performance Decided to design and optimize systems in a laboratory Could then provide contractors with more detail installation guidelines

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36 Lab work Idle losses Steady state efficiency Air handler capacity testing Full system tests Cyclical performance Maximum capacity

37 Idle Losses Setpoint = 140 F $1/therm $0.12/kWh

38 Boiler 1 Combi boiler with 12 gal DHW tank

39 Tankless Water Heater 1

40 Storage Tankless Hybrid

41 TANK 2

42 Steady State Simulated Heating Load Test Water Temp Water Flow Consumption Work Horse Heating Plant Constant Return Water Temp Heating Supply Return Tested Heating Plant TWH TANK BOILER DHW Supply Return Electric Gas

43 Steady- State Heating Plant Efficiency at Tset=130, GPM=4 Going from 90% to 80% increases heating bills about $150/year in MN

44 Air Handler Performance Mapping Minimum supply air temperature (110 F) for comfort dictates minimum flow rate Maximum return water temperature (105 F) dictates maximum flow rate Coil capacity is bounded by these flow rates

45 Air Handler Performance Mapping 52,500 57,000 kbtu/hr 45,500 54,000 kbtu/hr

46 Low Use Transient Performance

47 Low Use Transient Performance

48 Low Use Transient Performance

49 Max Capacity Testing Next Slide

50 DWH Supply

51 Field Implementation and Monitoring Up to 400 installs in Minnesota before December 2012 Utility bill analysis on all 400 sites Detailed pre/post monitoring on 20 sites

52 Existing Equipment Conditioned Space Cold In from Mains DHW Loads Hot Space Heating Air Runtime Air Temp Ambient T ND Tank Water Heater Single Stage Furnace Outdoor Gas Electric Gas

53 Dual Integrated Appliance Installation Conditioned Space Cold In from Mains DHW Loads Ambient T Hot Space Heating Air Water Temp Water Flow Air Temp Air Flow Consumption Supply to AH Water Heater Return from AH Hydronic Air Handler Outdoor Electric Gas Electric

54 Field Monitoring Installation

55 Looking at sites with complete data On average calculation was 22% oversized About 20% oversized when only looking at good fits

56 Field Study: Expected Results Better understanding of installed costs for different systems after contractors have become familiar System design specifications and quality control requirements Installed efficiencies of Dual Integrated Appliance systems and savings potential

57 PRELIMINARY: Energy Consumption Data Represents about a 100 therm/yr savings or about 10% of the natural gas space heating bill

58 58 Questions

59 Given human nature, it is our job to provide the infrastructure that supports efficient behaviors.