Recently featured in Abode Magazine, this new- build overlooking Coronet Peak gave us the opportunity to fully showcase our culture of innovation when designing & installing their plumbing, heating and ventilation systems.

The large 323m2 home, known as “Wings over Water”,  has a double twisted plane roofline, beautifully resembling a butterfly. The house is entirely clad in cedar, a major focus for builders Shore Construction, and looks out over an artificial pond to the mountains beyond. 

The design of the house, initially conceived by Kamermans Architects, is all about making efficient use of the sun. Homeowners Bob and Wendy wanted something energy efficient – and different. The house is built to a very high insulation standard and it reaches far above the Building Code: pushing on the edge of being Passive House Certified without quite going to that level.


Why Optum?

Bob and Wendy’s vision for an integrated system that was both renewable and efficient to run aligned perfectly with our commitment to cutting-edge plumbing solutions, so we were more than happy to design their system when approached by them- they had been following our work for some time.

First steps- the calculations. 

The home’s extensive use of glass necessitated really accurate heat loss calculations. Here we instilled confidence that we could not only meet, but surpass their comfort expectations- important in the extremes of temperatures experienced in Central Otago. Our choice of a Stiebel Eltron air-to-water hydronic heat pump as the primary heating and hot water energy source was a decision driven by its exceptional efficiency and remarkably quiet operation. This aspect was particularly crucial since the home resides in a serene rural setting, where tranquility ranks high on the priority list.





The Heart of the System: The Rotex Sanicube

Central to the system is the Rotex Sanicube, a 500L highly insulated thermal store designed to accommodate all energy sources required for heating and hot water. With the heat pump, an electric backup element, and a Rinnai gas water heater interconnected, the Rotex provides a versatile hub that ensures a continuous supply of warmth and comfort.

The intelligent design of the Rotex allows it to deliver hot water at higher temperatures while utilizing a heat exchanger positioned lower in the tank for extracting lower temperature water. This water is directed towards the underfloor heating system, offering a remarkably efficient way of heating using lower temperature water. The Rinnai water heater serves as both a top-up solution on colder days and a backup option when all power sources are unavailable.


Harnessing the Power of Solar and Efficiency

The integration of PV solar panels brings an added layer of efficiency and sustainability. By directly connecting the PV solar to the heat pump, we unlocked a high-efficiency solution where solar energy powers the heat pump. This synergy yields exceptional efficiency, often exceeding 400%, meaning that for every unit of energy used to run the heat pump, up to four units of energy are produced for heating and hot water.


Our Innovative Approach: Manifold System

In this project we had the opportunity to address the challenge of fluctuating water temperatures during simultaneous water usage, a common issue in many households, when everyone wants to take a shower at the same time. To eliminate uncomfortable scenarios, we implemented a “manifold system,” similar to underfloor heating. This ingenious setup involves separate pipework for each bathroom, preventing temperature fluctuations.

Furthermore, to minimize waiting times for hot water to reach distant bathrooms, we also introduced a hot water ring main pump. This strategic addition ensures swift delivery of hot water to even the farthest corners of the home, enhancing convenience and conserving energy.


Would we change anything?

Frankly- no. We’re proud of this work, and it stands as a testament to our commitment to innovation, efficiency, and client satisfaction. At Optum we create comfort and consistency for our clients, through designing heating and ventilation solutions that work for life.