Residential Hot Water Use Monitoring Field Study

Presented by: Doug CaneCaneta Research Inc./Caneta Energy(Research sponsored by Union Gas)

Presented at: CMX-CIPHEX 2012March 22nd, 2012

Caneta Research Inc.(Caneta Energy)

• Caneta services :– engineering research and analysis, monitoring and management

services. – energy consulting and code compliance modelling services to

owners and design teams for new buildings.– www.canetaenergy.com

Background• Caneta was contracted by Union Gas to perform a field

study to measure residential hot water use.• Goal was to determine variables that affect Domestic Hot

Water (DHW) use, and determine DHW use patterns.• Study participants were from 3 areas in Ontario within

Union Gas territory (Hamilton, London, and Sudbury).• Monitored water heaters for 2 week periods between 14th

August, 2009, ending October 22nd, 2009.• Monitoring equipment provided by NRCan.

Monitoring Equipment13 Kits Consisting of:•Data logger: set to record DHW volume every 4 seconds•Pulse output flow meter•Custom power supply for flow meter•Electric Pulse Input Interface•Surge protectorInstalled in 37 Homes

– 16 in Hamilton– 11 in London– 10 in Sudbury– Of these, 1 site had unusable data, 3 others had errors

Homeowner Survey• Each homeowner filled out a survey characterizing their

home and how they use hot water• Survey fields included: occupancy patterns, types of

occupants, number and type of fixtures/appliances, frequency of fixture/appliance use, and house characteristics

Example of Survey Results

Summary of Data – Draw Volume• Average daily draw volume for a typical year is 199 Liters

(site average 197 Liters per day)• Equates to 63 Liters per person per day

Data Summary - Draw VolumeDraw Volume per Home per Day (L/day) by Number of

Occupants:

Data Summary - Draw VolumeDraw Volume per Person per Day (L/person/day) by Number of

Occupants:

Data Summary - Draw Volume

Draw Volume per Person per Day (L/person/day) by Location:

Data Summary - Draw Volume

Draw Volume per Person per Day (L/person/day) by Tank Size:

Summary– Draw Frequency• Short small draws accounted for a large number of DHW draws• Potential issue with some data not being real draws (phantom draw)• Average of 103 draws per day including phantom draws, and 73.9 draws per day excluding

phantom draws• Phantom draws account for an average of 0.93 Liters per day, which is insignificant• Average home draws hot water for 44.5 minutes per day including phantom draws, and

44.2 minutes per day excluding phantom draws

Data Summary - Draw FrequencyAverage Number of Draws per Home by City:

* Data used for this plot includes phantom draws

Data Summary - Draw FrequencyAverage Number of Draws per Person by City:

* Data used for this plot includes phantom draws

Conclusions• A typical daily draw volume is 199 Liters, or 63 Liters per

person per day• A typical water heater will experience 73 draws during

one day• On-demand and storage water heaters have similar use

patterns