Field Study of An Intelligent, Networked, Retrofittable Water Heater Controller ACEEE Hot Water Forum - Portland, OR Ben Schoenbauer CEE & David Kalensky, GTI February 2017
Acknowledgements This project is supported in part by grants from the Minnesota Department of Commerce, Division of Energy Resources through a Conservation Applied Research and Development (CARD) program Gas Technology Institute is the project lead Aquanta is the project s industry partner Pg. 2
Project Goal To validate the field performance and energy savings of an innovative, intelligent, networked water heater controller for residential and small commercial storage water heaters for potential inclusion within Minnesota s Technical Reference Manual (TRM) and as a program measure within Conservation Improvement Program (CIP) portfolios. Pg. 3
Methodology Install 30+ controllers Mix of gas and electric Mix of hot water loads Mix of inlet water conditions Detailed M&V on 10 sites Detailed Instrumentation w/ high resolution data collection Alternating mode analysis Evaluating different control algorithms Analysis of controller Assess installation Characterize energy performance Characterize impact on energy use profile Assess the impact on hot water delivery Evaluate the devices measurement capabilities Pg. 4
Installation and Validation Tank Sensor through TMP Valve Control Units Electric Gas Valve Additional Sensors Leak Detection Water Inlet Temperature Pg. 5
Installation and Validation Site Fuel Type Water Heater Size Water Heater Unit Hot Water Use (GDP) Number of Occupants Energy Factor d216_gas_01 Gas 50 American Standard PCG6250T403NOV 36.2 4 0.70 d216_gas_02 Gas 40 Rheem XG40S09HE38U0 18.1 2 0.62 d216_gas_03 Gas 50 AO Smith FPSH 50 250 34.0 2 0.62 d216_gas_04 Gas 50 AO Smith GPVL 50 200 52.5 4 0.70 d216_gas_05 Gas 40 Rheem 43V P40 SE2 35.0 2 0.67 d216_elec_01 Electric 50 Rheem PROE 50 T2 RH95 24.6 2 0.95 d216_elec_02 Electric 50 Marathon MR 502 45 B 31.3 1 0.95 d216_elec_03 Electric 50 Reliance 606 650 DOCT 36.0 5 0.90 d216_elec_04 Electric 50 AO Smith ECT 52 200 45.6 8 0.91 d216_elec_05 Electric 50 Bradford White M250T6DS-1NCWW 31.6 4 0.90 Pg. 6
Installs Pg. 7
Field Sites Figure 2 16 Field Sites in the Greater Minneapolis / St. Paul Area (12 Natural Gas; 2 Electric) Figure 1 33 Field Sites in Minnesota (22 Natural Gas; 11 Electric) Figure 3 9 Field Sites in the Duluth Area (4 Natural Gas; 5 Electric) Pg. 8
Inlet Water Temperature [F] Inlet Water Temperature 80 75 70 65 60 55 50 45 40 35 d216_gas_02 d216_gas_01 d216_gas_03 d216_gas_04 d216_gas_05 d216_elec_01 d216_elec_02 d216_elec_03 d216_elec_04 d216_elec_05 30 7/19/16 9/7/16 10/27/16 12/16/16 2/4/17 3/26/17 Pg. 9
M&V Instrumentation Pg. 10
Preliminary Performance Energy Savings Reduced stand-by or idle loses Lower tank temperatures (through reducing set point) Eliminate unnecessary reheats (through lock out) Reduction of over heating (through reducing set point) Pg. 11
Delivered Water Temperature Supply Water Temperature 135 130 125 120 115 110 AI_2 AI_1 Base_2 Base_1 105 0 20 40 60 80 100 Daily Hot Water Use [GPM] Pg. 12
Energy Use Profile Pg. 13
Energy Use per Gallon (Btu/gal) Energy Use per Gallon of Hot Water 1200 1000 800 600 Base 400 Controlled 200 0 40 45 50 55 60 65 70 House Inlet Water Temp Pg. 14
Energy Use per Gallon Btu per gallon is lower with the controller active at all 10 sites Energy per gallon is reduced up to 15% Energy use per gallon is NOT water heating savings If the water temperature has changed the flow profile may have changed Pg. 15
Hot Water Delivered (btu/day) Hot Water Load 40,000 35,000 30,000 25,000 20,000 Baseline Controlled 15,000 10,000 5,000 0 40 45 50 55 60 65 70 House Inlet Water Temperature [F] This site as the longest monitoring time had shows ~10% savings Pg. 16
Controller as a Measurement Device Direct measurement Change in total tank energy Current sensing (on/off) Power usage (kwh) Cold water inlet temperature (F/C) Derived values from data: Water heater energy input Water heater energy output (load) standby loss Hot water usage Hot water available Pg. 17
Conclusions Smart controllers can control water heater usage profiles eliminate unnecessary reheats reduce energy use for water heating Measure, calculate and provide data and information to occupants Future Monitoring through the summer 2017 Project completion in fall 2017 Pg. 18