The Application of Ground-Source Heat Pumps with Waste Water Systems

The use of waste water, both grey and black, as a heat source or sink is not a new concept. But, until recently, the availability of cost-effective, factory-constructed systems has been limited.

Now, with these new systems hitting the market, engineers have more options than ever for designing more sustainable facilities. One such way the marketplace is utilizing waste-water technology is through ground-source heat pumps.

However, many engineers may be hearing pushback when they suggest incorporating waste
water into plans. Maybe you’ve heard or said it yourself: “We’ve never done this before.”

To combat the obstacle of pushback, engineers must outline the project goals to demonstrate
good engineering concepts and application guidelines:

• Understand the application of waste-water energy recovery systems for heating and cooling applications
• Understand characteristics of unconventional water sources and their applications as the heat sink and heat source for ground-source heat pump operations
• Recognize the capital cost requirements to effectively implement heat recovery from unconventional energy sources
• Understand the importance of performing a thorough site investigation of the project location to assess the site limitations and unique features

Case Study: Grey Water Energy Recovery

Project Type: Retrofit of laundry area for 350-room hotel
Project Location: Alberta, Canada
Project Size: 6,000 gallons of hot water/day
Average Run Time: 10.7 hours/day
Average Output: 1.28 million BTU/day or 375 kWH/day or 1,700 gallons (50° to 140°F)
Average Performance: 4.71 COP
Peak Performance: 8.77 COP
Estimated Annual Savings: $40k/year

Melink Corporation provides turnkey management of geothermal projects for architects, engineers, ESCOs, and building owners, as well as consulting services for architects and engineering firms. Interested in geo for your business? Leave a comment below.