Hydronic Heating: Simple and Efficient Central Heating Solution

Hydronic heating, or water-based heating, is the world’s most efficient central heating system.

It’s common in European households but less so among Kiwis because it’s typically more expensive to install than other heating systems.

How hydronic heating works

Traditional heaters such as woodburners, electric heaters or heat pumps have one major flaw: they only heat the room where they are installed while the rest of the house remains cold. Although the heat they produce can somewhat spread in open-plan houses, it’s a different story for houses with separates rooms.

Hydronic heating solves this issue by spreading heat uniformly throughout the whole house, including multi-storey dwellings. It’s a rather simple process. A hydronic system simply heats water and sends this hot water through insulated pipes to anywhere in the home where heat is needed. As it takes a lot of heat to raise the temperature of water, the hot water carries a great deal of heat energy and releases radiant warmth.

Components

A hydronic heating system has 3 main components:

• a heat source that is placed away from where the heat is required
• a hot-water distribution system
• a heat emitter for releasing the heat where it’s needed.

All components are monitored and controlled via a control system.

Heat source

Hydronic heaters use a boiler system which quietly and quickly heats the water. Different models are powered by gas, diesel, burning wood or a heat pump. The best type to use for your home depends on various things including the size of your house and your locality, so it’s best to talk with heating experts if you’re thinking of installing one.

Heat distribution system

To transfer heat to where it’s required, the heated water is distributed through a system of sealed pipes with associated control valves and pumps. The pipes run from the boiler to individual radiators or an underfloor slab.

Modern hydronics technology enables heat to be delivered precisely where and when it is needed. The system can be configured to heat each room separately, so you can adjust the warmth according to the comfort level of the room’s occupant and keep unoccupied rooms at a minimum temperature.

Heat release

Radiant heat is released into the house via underfloor heating and radiators.

Underfloor heating is formed by laying a buried grid of pipes before an insulated concrete floor slab is poured. It may also be retrofitted under existing timber floors or over existing concrete floors. The hot water circulating in the pipes warms the floor and evenly distributes heat inside the room.

On the other hand, wall-mounted radiators can be placed anywhere in the house and sized to suit every room. Each room’s temperature can be individually controlled as most radiators have a controlled valve.

Advantages of Radiant Heating

• Radiant flooring and hydronic heating equipment work in silence.
• Unlike in forced air heating systems, hyrdonic heating makes it easier to maintain a balanced humidity level in the home because it does not dry out the air.
• Radiant heat has no bursts of air so you don’t have to worry about pushing warmth out of the areas you need it.
• Thermal radiation reduces air temperature stratification, which in turn reduces heat loss through the ceilings. This ensures not only your comfort but also your home’s energy efficiency.
• Hydronic heaters can also be used for heating towel rails, floors or even swimming pools.

How much will it cost me?

According to Consumer.org,nz, installing a hydronic heating system may cost you anywhere from $13,000 to over $40,000 depending on your house and the type of system you choose. Add to this the running costs which can vary from around 6 to 20 cents per kWh.

Generally, heat-pump hydronic systems have the lowest running costs. But for homes with reticulated gas, a gas system makes more financial sense as it would mean lower installation and running costs.

Since hydronic heating does not actually heat water up to boiling temperature, your boiler runs more efficiently and further reduces your energy bills.

In order to maximise the benefits of a hydronic heating system, all components must be specified correctly for your home. Use an experienced heating company to assess your heating needs and oversee the installation.