In my last cold beverage related… ehh… I mean refrigeration related blog, we learned about complicated stuff like how the refrigeration cycle works and how water savings can be achieved by retrofitting old systems. Since we’re all experts already, I’ll skip all the boring techno-babble and get straight to the good stuff.
Our old refrigeration system at Toronto Rehab’s Bickle Centre used domestic water to cool the refrigeration condensers, meaning that to keep our fridges cold we were continuously pouring water down the drain. How much water? I’m glad you asked because we set up an ultrasonic flow meter on the discharge line to measure just how much water (and $$$) we were sending down the drain.
As you can see from the chart, we were consistently dumping over 4,000 gallons per day of clean drinking water down the drain! That’s over 20,000 large double-double iced coffees worth of water each day!
Luckily, there’s more than one way to bake a cake and there’s more than one way to cool a condenser – working with TRI’s Nutrition department, we replaced all of the old refrigeration equipment and installed new air-cooled condensing units outside near the loading dock.
As a result, the new system has eliminated all the water waste described above and also improved the reliability of the system by replacing aging equipment. For water to air cooled conversion projects, it is common for electricity consumption to increase slightly because heat transfer is more difficult to air than to water. However, for this project we are expecting to actually decrease electricity consumption due to the implementation of the following efficient technologies:
- Condensing unit fans and compressors use high efficiency permanent magnet motors
- Fans operate at variable speed according to demand
- Electronic expansion valve modulates condensing pressure/temperature on demand to minimize loading on the compressor
Here are the expected annual savings from the project:
Water savings: 6,023 m3/year (more than two Olympic sized swimming pools!)
Electricity savings: 8,000 kWh
Cost Savings: $16,000
Throughout the project, access to at least two refrigerators was maintained in order to minimize disruption to the critical task of feeding our patients. The project required a lot of coordination and wouldn’t have been possible without the support and attention from the nutrition department, including Susan Grove, Laura Boos, and Jane Morgado. We would also like to thank Stantec and Nutemp for a smooth and well executed project. Now where’s that cold beverage I was talking about??
As an interesting aside, UHN is getting some well deserved media recognition for our culture of energy conservation. Let’s keep building that momentum!