In 2016, during the design stage of construction on the Prestons Lodge aged care facility in south west Sydney, JHA Consulting Engineers approached Rheem Australia to provide an energy efficient solar and warm water proposal that included budget estimates, STC rebates and pay pack periods.

The 132-bed aged care facility was built in 2016 by Advantaged Care, a leading provider of aged care facilities in Sydney, to provide a homely, secure and safe environment for residents.

The challenge was to provide energy efficient, budget conscious options for the hot and warm water plant requirements, while the large number of beds meant that capital and ongoing maintenance costs of providing safe tempered water needed to be considered.

Rheem’s solution was to combine gas and solar heating, which will result in a saving of $95,600 in hot and warm water running and maintenance costs over 10 years.

Hot Water Requirements

The daily hot water load for the facility is 9,175L. 38 NPT solar collectors would provide 50% of the total hot water load in December and 37% over the full year.

Warm Water Requirements

A study comparing the capital, installation and ongoing maintenance costs of TMV’s versus a centralised Rheem Guardian solution was undertaken.

Solution

3 x heavy duty gas 275L water heaters

38 x NPT solar collectors

14 x storage tanks

1 x 240L/min Guardian warm water

2 x 250L/min ultraviolet disinfection

Hot Water Running Costs

The estimated annual hot water consumption is approximately 3,348,875L based on 100% occupancy, which equates to 2,479MJ per day at 2.5c per MJ.

The average annual solar contribution is 37% or 888 MJ per day. The estimated annual running cost for gas only is $22,618, or $14,515 for gas and solar. This means the estimated savings are $8,103 per annum.

Warm Water Costs

The estimated capital and installation cost for TMV (assumed one TMV per two rooms) is $42,773, plus an additional $23,980 for guardian and UV disinfection.

The estimated annual maintenance costs for TMV are $10,334 and $3,400 for guardian and UV disinfection.

The centralised solution realised approximately $18,500 in up-front cost savings and a further $6,900 per annum in ongoing maintenance costs, providing a life cycle cost saving over 10 years of around $87,500.