When plans were made to bring the Lincoln University Recreation Centre into the 21st Century, a hot water system was needed that could not only deal with the large demand for potable hot water from showers for the onsite gym and surrounding fields, but could also withstand the expected growth in memberships and assist with the centre's goals towards a low-carbon future.

The Mitsubishi Electric Hot Water Heat Pump Solution – Ecodan QAHV CO₂ Hot Water Heat Pump

With the future availability of natural gas clouded in uncertainty and the potential risk to occupants if a leak occurs, the Ecodan QAHV Hot Water Heat Pump offers a safe, low-carbon alternative to gas water heating with higher efficiencies and compact dimensions to minimise plant space.

Specifically designed to produce high temperature potable hot water up to 90°C, the large 40kW capacity QAHV CO₂ Hot Water Heat Pump was the ideal solution for the recreation centre which experiences high potable hot water demand daily.

CO₂ (R744) Refrigerant for Low Environmental Impact

Utilising CO₂ as an environmentally friendly, safe and natural refrigerant with zero Ozone Depletion Potential (ODP) and a Global Warming Potential (GWP) of just 1, the Ecodan QAHV Hot Water Heat Pump provides a green, highly reliable and future-proofed alternative to traditional boiler systems for the Centre’s potable hot water needs.

Better Security of Hot Water Supply and More Lettable Space

As a single pass high temperature lift machine, QAHV works best with a high water temperature difference and delivers 10l/min or more of full temperature usable hot water in real time.

This directly reduces the amount of storage required to meet the Centre’s peak demands, and gives quicker recovery so members will never be caught out with a cold shower — no matter how busy the Centre is that day.

Superior Heating Performance Even at Low Temperatures – Perfect for Canterbury’s Cold Winters

As ambient temperatures drop, so too does the capacity of heat pumps. However, the QAHV is able to provide its full heating capacity of 40kW even at ambient temperatures as low as -3°C. Furthermore, the unit operates to supply 90°C hot water in ambient temperatures as low as -25°C.

With an average of 65 ground frost days a year in the Lincoln area*, a system that is reliable on the coldest of days is essential to the facility.

*Ground frost days refers to the mean number of days per year of ground frost according to the NIWA website.

The Result – Highly Efficient Water Heating Performance

The result is a beautifully built $10 million, 2,087m² facility with a QAHV providing potable hot water to the bathrooms in all changing rooms onsite. Lincoln Recreation Centre avoids relying on a high carbon emitting LPG driven plant, now enjoying a high COP unit that utilises CO₂ refrigerant for low environmental impact.

Twelve months into its stage 1 operation, Mitsubishi Electric's data shows that at an ambient air temp of 17˚C the unit was delivering around 11l/min of hot water at 71˚C — with an amazing efficiency of over 3.6:1.