Leuschke Kahn Architects has recently renovated a character villa located on a quiet street in Remuera. When the owners decided they wanted to add an indoor pool to their home, they turned to Hot Water Heat Pumps Ltd to supply the heating and ventilation system. With over 30 years in the business, they knew the company's expertise and know-how would provide a green, clean, condensation free, comfortable and warm environment, suitable for the young family.

The Challenges

The architects needed a solution to control the excessive humidity for the 36m² large lap pool (complete with heavy duty pool cover) for the modern purpose-built extension they had designed at the rear of property. To establish the exact requirements for the indoor pool, Hot Water Heat Pumps Ltd conducted a site visit with the clients, architects and builders (Building and Restoration Services Ltd).

The conditions for the project included the temperature to be maintained at 29°C — 31°C all year round with no condensation in the pool facility. "Indoor heated pools lose about 70% of heat which could lead to user discomfort and deterioration to the interior surfaces," explained Bahman Al Nadaf from Hot Water Heat Pumps Ltd. He suggested that if a simple extract system was used it would be detrimental to the clients' requirements because it would remove too much heat from the pool enclosure, leading to a higher evaporation rate.

The Solution

To compensate for the evaporation rate and condensation, the team at Hot Water Heat Pumps Ltd suggested a Duoheat dual purpose heat pump providing heating, and a Vent-Air air distribution and ventilation system. The system would include condensation controls suitable for covered pools, with a ventilation system running when the cover is removed from the pool to ensure there would be no condensation, keeping the atmosphere pleasant and comfortable. When the cover is off, there is a higher evaporation rate causing the heat pump to have to work harder to compensate for the additional heat loss from the pool and greater air heating and ventilation system requirements. The technically advanced 7GP17Ub11-1 Duoheat heat pump would easily be able to cope with the extra demand.

All purpose-built parts for the bespoke system were designed and assembled at Hot Water Heat Pumps Ltd's factory in Henderson, New Zealand. The heat pump runs at a cost of 75 cents an hour, if the user pays 25c per kW for electricity, with an additional $1 per hour to run the ventilation system, (based on 25c per kW) making total running costs of $1.75 an hour. The equipment for the system is housed in an area attached to the family's double garage, which has easy access for servicing and maintaining equipment.

The Result

The turnaround on the project was impressively swift. The initial phone call to Hot Water Heat Pumps Ltd was made in February on Waitangi Day, followed by a site meeting four days later with the architect and builder. After a further fifteen days, the contract was signed, and the job was finished by the end of November.

Commenting on the project Bahman said, "Adaptability and flexibility are always important considerations on any job and we always aim to ensure that the systems installed can cope with future changes in circumstances." The family is now expanding with the arrival of a new baby expected soon and it will be necessary to raise the temperature of the pool to 33°C for the comfort of the new addition. Hot Water Heat Pumps Ltd will be adding a supplementary heat pump to boost the temperature to the required level.