Heating Systems
The Challenge:
Keeping NZ homes warm, dry and healthy through the winter can be a concern with increasing electricity costs and extreme weather conditions.
Many homes are not heated consistently, with perhaps the main living room heated but the bedrooms and other areas suffering temperatures well below the minimum of 18°C required under the Healthy Homes Standards and recommended in WHO guidance.
GO TO HEALTH
“Underheated homes, ill health and financial stress of energy bills are a reality for many Kiwis.”
BRANZ:
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“One of the back bedrooms, in the middle of winter, it’s minus 2 degrees on the inside of that window, on the inside of that room.”
Dan Saunders
BRANZ’s Household Energy End-use Project second phase (HEEP2 – Nov 2024) found that:
Almost half (48%) of people in the survey reported that their home felt colder than they would like at least some of the time in winter. Around 1 in 5 said they could see their breath and 1 in 5 shivered at least some of the time in winter
One third (33%) of homes in the survey were damp, 75% had condensation, and 48% had mould
While 85% of people in the survey heat their main living area in winter, 41% never heat their bedroom and over 30% of young children’s bedrooms were never heated DOWNLOAD PDF
While heating can account for around a third of energy use in a typical NZ house, there are many ways to help ensure comfortable, consistent heat levels in the home including smart design, good insulation, internal moisture control, and high performance windows. Practical, efficient options include heat pumps and central heating systems.
Heat Pumps:
Heat pumps are increasingly common in both new build homes and retrofitted into older homes – in 2018, nearly half (47.3%) of NZ homes had a heat pump.
Massey University.
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Heat pumps work by transferring heat using a refrigerant and a compressor. They also filter the air, removing dust and allergens, and help reduce humidity minimising mould risk:
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They are effective for both heating in winter and cooling in summer:
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Hot water heating takes around 30% of the average NZ household’s energy use and many homes are installing or retrofitting hot water heat pumps:
“Hot water heat pumps typically use around 60% to 75% less electricity than conventional electric hot water systems and can heat and store water to the same temperature and volume.”
EECA:
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Underfloor Heating:
In 2015 BRANZ found that only 5% of its random sample of NZ homes had central heating, but with more homes being constructed with concrete slab floors, more new builds are including hydronic underfloor heating systems, often utilising hot water heat pumps.
Using a network of pipes installed in the concrete foundations, the system runs heated water through the floors, maintaining a consistent level of warmth throughout the home
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Hydronic underfloor heating maximises the advantages of the heat retention properties of concrete, building on the thermal mass of the floor slab.
Warmth NZ:
warmth.nz
While today’s hydronic underfloor systems utilise sophisticated technology, this method of heating living spaces has a long proven history:
“Hydronic underfloor heating has been used for centuries. The Romans heated their homes using the same approach over 2000 years ago.”
Warmth NZ:
warmth.nz-faqs
“Underfloor heating – On the Superhome Tours in winter, people take off their shoes, then experience the warm floor, they’re like ‘Ohhh wow!’ That’s changed completely people’s perspective on concrete floor, it’s not cold, it doesn’t have to be.”
Julie Villard: Architect and Eco-Design Advisor, Christchurch City Council
“Warmth NZ hydronic underfloor heating and hot water heat pumps for new builds – water pipes installed into the foundations, use heat pump technology to heat that water which transfers the heat throughout the whole home. The same heat pump can also heat your hot water cylinder, so make it really cost effective.”
Hanshu Li: Warmth.nz
“Heating system you can feel – Warmth underfloor heating system, a dual system for efficiency – a hot water heat pump heats the water that goes into the cylinder for potable use, taps and appliances – the same water is circulated through the flooring system – hot water heat pump is three times as efficient as a standard electric heat pump.”
Guy Gillespie: Character Builders
“Only heating source is hydronic underfloor heating, heats the house quite adequately – goal to be in the house in winter in shorts and singlet, achieved that goal over winter, quite nice.”
Clayton Mitchell: Statement Homes
“Hydronic underfloor heating – people think about electric wires in the floor, this is not the kind we’re talking about. We put water pipes into every room of your home, embedded into your concrete – it’s a closed loop system. We go in when the builder pours the foundation, put the pipes in, the come back when the house is almost finished to put a heat source, a hot water heat pump outside, like a traditional heat pump but instead of heating air it heats the water. Water carries 3,000 times the energy compared to air, concrete is 2,000 times, that’s why we embed it in the concrete.”
Hanshu Li: Warmth.nz
