Monitoring the HomeSmart Home

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Once the family moved into the HomeSmart Home, BRANZ monitored their energy and water use, energy generation, greywater use, and indoor temperatures and humidity.  Monitoring continued for 12 months, starting in December 2009 and running for 2010.

Monitoring of the temperature and relative humidity in the living room and the main bedroom was carried out using two Hobo U10 data loggers.  The Hobo is a two-channel temperature and relative humidity logger with 10-bit resolution. The logger can measure and store up to 52,000 samples with a sampling frequency down to one per second.

Both loggers were placed in non-intrusive locations (one in the living room and one in the main bedroom) that were not exposed to direct sunlight.  Sampling was performed at a rate of one measurement every 10 minutes. To monitor household energy use, the meter used by the electricity retailer was read every two months.  Withing the home, a three channel electricity meter was used, with the three channels assigned to:

  • the electrical output of the PV array
  • the electricity input required by the greywater system
  • the electricity input required by the rest of the house

The three channel electricity meter used was a VM series Direct Connect Meter - VMP3120-230 from Energy Intellect™ . This device allows for remote communication using the cellular network. Daily data was retrieved by Energy Intellect and sent to BRANZ on a monthly basis.  The sampling period was set at five minute intervals.

In monitoring the greywater system, both the energy and the amount of greywater used were of interest. Measuring the greywater flow at the outlet with multiple water meters was not a feasible option due to the water being contaminated. Therefore greywater consumption was measured by proxy based on the energy use of the pump. Toilet flushing and refilling of the fixed volume cistern creates repeating patterns in energy use link to a particular volume water displaced from the greywater reservoir to fill the cisterns of the toilets.

All reticulated water used in the HomeSmart Home passes through a Kent/Elster meter, located along the driveway to the garage. A manual reading was taken at the start of monitoring and billing records from WaterCare Services Limited were used for the estimation of average water usage by the household over the monitoring period.


Hobo temperature logger

The Hobo data loggers recorded temperatures and humidity