Stephen Jones from Stephen Jones Architects Ltd had undertaken a renovation project in a very nice cul-de-sac in Mt Eden. The house had an existing outdoor pool the owners wished to transform into a health and recreation area, adding an indoor pool, spa, gym, sauna, steam room and a games room. Kerry Richmond from Auckland Inground Pools Ltd had worked with Hot Water Heat Pumps Ltd on another indoor pool heating and ventilation project and introduced them to Stephen, who was seeking a specialised team to design and build the necessary equipment to control the water temperature and condensation for the indoor pool.

Stephen visited the Hot Water Heat Pump factory in early September 2012, and from there it took about three years from conception to the realisation of this project.

The challenges

The challenge Hot Water Heat Pumps Ltd faced was ease of access to each zone, providing not only thermal comfort for each area, but also making sure that the evaporation from the pool and spa would not cause any damage to the structure and the rest of the home. It was suggested that the pool and spa would be separated from the other rooms by glass to enhance the view, natural light and a sense of space.

The next challenge was to convince the client of the benefits of a proper swimming pool cover. Using a cover would reduce the running cost, as it reduces the evaporation losses from the surface of the pool, therefore minimising the running hours of the Duoheat and Vent Air System.

The third challenge was to find a location for the mechanical and pool plant room. A significant amount of latent energy leaving the enclosure could be recovered, which would otherwise go to waste.

The solution

From an energy saving point of view, it is best to have all the mechanical equipment in a dedicated room. The Duoheat Heat Pump was the logical choice with the further advantage of a smaller overall footprint, eliminating the need to invest in individual heat pumps for both the pool and air handling system. The Duoheat units had been designed, manufactured and perfected locally in Auckland since 1982. Duoheat is the chief component that offered the owners the lowest life cycle costing compared to other heat sources.

Utilising a Duoheat heat pump as the heat source provides efficient heating for the pool water and also efficiently provides hot water for the Vent-Air supply air handling system. The Duoheat heat pumps heat both bodies of water directly with no efficiency loss from an additional water to water exchange found in many combination heat pumps. This achieves greater energy savings for the end user. Where necessary, an extra heat recovery coil would add to the benefits of the Vent-Air system, which would further reduce the overall heating cost.

The specialised Indoor Pool team at HWHP collaborated with Stephen Jones and designed the Indoor Pool Heating and Ventilation System around HWHP's 7GP25A18-3 Duoheat heat pump and Vent-Air 210 supply and return air handling system. The air distribution system is via a concealed underground system, where warmed air is introduced to the pool enclosure to keep the enclosure comfortable, healthy and condensation free at all times.

The result

Over the past 14 years, HWHP has designed over 70 indoor pool ventilation and condensation control systems based on Duoheat heat pumps and Vent-Air systems both in New Zealand and overseas. Their experience has proven that a good understanding and collaboration amongst all parties involved, from the clients, to the architects, to the builders and all other trades, paves the way for a smooth and successful renovation. The result is an immaculate masterpiece the owners can truly enjoy.