13apr hydronic heating hero2
Research report
4 April 2013

Hydronic heating

Hot water is one of the most effective form of home heating.

Member comments

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Geoffrey M.
14 Mar 2019
Polarenergi NZ

I recently saw this technology at a home show and it seemed very interesting. We are building a new house so the very low running costs were of interest.

The benefits they claim are the following. Any feedback would be most welcome.

Some key differences and benefits of Polar Energi over and above other systems...

The unique design in the transfer of energy in the refrigerant gas to the DHW and waterborne floor heating system is what makes Polar Energi more effective in operation and a world-leading product.

• No circulation pumps for domestic hot water.

• No 3-way valves for domestic hot water.

• No electric input for the domestic hot water.

• No additional energy losses through a secondary heat exchanger for domestic hot water.

• Low storage volume – quick recovery it equals more efficiencies with 400L plus of hot water in the first hour. (This is equivalent to a 300L system).

• No buffer tanks required for fluctuating flow rates on the central heating system.

Its efficiencies come from a unique, future thinking design of the Polar Energi cylinder.

Key Benefits - Superior warranties

• Panasonic Inverter Heat Pump – 5 years warranty

• Polar Energi Cylinder – Stainless Steel, electric anode – 10 years warranty

• PV compatible with its intelligent RTC5 controller (standard)

• Great for new homes and existing systems upgrades

• It’s 35% more efficient than any other heat pump and equates in an actual saving in running costs of 100%

• Polar Energi has options to suit your personal requirements.

Lynda M.
22 Feb 2019
Diesel boilers

Have you any comments re diesel boilers for radiators? We live out of town in a villa so no piped gas and gather bottled gas is a costly system. thanks

Consumer staff
27 Feb 2019
Re: Diesel boilers

Hi Lynda,

We don’t currently have any information on diesel boilers, but you might find our article on home heating useful when comparing running costs: https://www.consumer.org.nz/topics/home-energy-costs

Kind regards,
Natalie - Consumer NZ staff

David M.
27 Jun 2018
Can suck a lot of energy

We built & installed our own underfloor and radiator hydronic heating from standard components. Some lessons after the fact
* Pipes have to be securely tied to mesh, surge of concrete pour can dislodge them from sticky brackets
* Pipes closer to the surface obviously heat better and lose less heat to ground
* The special under concrete plastic compression pipes aren't sun tollerant. You can't leave the exposed tails out in the sun during the construction process, they go brittle & crack.
* Edge insulation of the slab is essential, often missed in older documentation or underfloor install guides
* Can suck a lot of energy. We use solar hot water, it would be uneconomic with direct electricity.
* Our European made steel with chrome over radiator has rusted in NZ conditions.

Previous member
15 Aug 2015
Review of Different Suppliers

Is there any review available of the different suppliers of hydronic heating systems? Also, is there a review of air-water heat pumps? I can only see the review of air-air heat pumps?

Previous member
17 Aug 2015
re: Review of Different Suppliers

Hi Mark,

Thanks for your inquiry. We don’t currently review hydronic heating systems or air-water heat pumps. EECA have some good information on heat pump water heating on their website: http://www.energywise.govt.nz/products-and-appliances/water-heating/heat-pump

You may also be interested in this 2009 pilot report comparing the energy and economic performance of a range of residential heat pump water heating technologies: http://www.eeca.govt.nz/sites/all/files/hpwh-pilot-report-final-15042011.pdf

George - Consumer NZ staff.