Hydronic Heating: Heating Your Home with Water

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Hydronic heating

While air conditioning is considered a necessity for the average Australian home, it’s important not to overlook heating as a home appliance to consider. If you’re shopping around for a new home-heating system, you might be considering hydronic. Long seen as the pinnacle of home-heating, hydronic heating is considered to be among the most efficient and attractive options. If you want to know more about hydronic heating, and see if it’s a good choice for your home heating and cooling, continue reading more below.

What is hydronic heating?

Hydronic heating is a relatively simple process. Unlike duct based heating, water is warmed in a gas boiler and then sent through pipes to heat a room or house through radiator panels or floor slabs.

This water circulates, before being returned to the gas boiler to be warmed again. Unlike other methods of home-heating, such as ducted, hydronic heating does not use fans or ducts to force warm air from one room to another but rather uses ambient heating to evenly distribute heat.

Not only is this a great choice for people with allergies, as there are no fans to spread dust or other allergens, but those who struggle with getting dried out from the moving air involved in ducted heating and air conditioning systems will be unaffected.

The lack of moving air increases also the energy efficiency of hydronic heating as energy is not needed to power fans.

Hydronic heating is considered to be one of the most efficient ways to heat a home. The water used during the hydronic heating process does not need to be heated to super-high temperatures (meaning it’s safe to touch for homes with children and pets), and is circulated in a closed system, so the water returned to the boiler remains warm.

This helps ensure that your energy bill remains low when using hydronic heating.

Types of hydronic heating systems

Hydronic heating systems can be used for everything from heating a pool, to warming towels in the bathroom, to heating a single room or the entire house. However, there are two main types of hydronic heating systems:

 Underfloor heating: Pipes are laid out and covered in cement. The hot water is sent through the pipes in the floor to heat the room through the floor. This can be for single rooms (like a bathroom), or an entire house.

 Radiator heating: The hot water is sent through pipes to wall-mounted radiators in the house. The radiators heat up, distributing the warmth in a room.

Both these hydronic heating systems are efficient, yet expensive to install, particularly in existing homes. While underfloor heating has the added benefit of being hidden, which keeps the home design more open and uninterrupted, it can also be very difficult to retrofit into a home unless you’re completely remodelling the floor.

Advantages and disadvantages of hydronic heating

Hydronic heating has many advantages, and is thought to be one of the best home-heating methods in terms of noise, efficiency, and safety. The biggest drawback, however, is the cost. Hydronic heating can be expensive to install in any home, and retrofitting a hydronic heating system into an existing property comes with an even higher price. However, once installed, hydronic heating systems can last 20 years or more with proper maintenance, and reduce your annual energy bill thanks to its efficient energy consumption.

Pros and cons of hydronic heating
Pros of hydronic heatingCons of hydronic heating
  • Super energy-efficient heating method
  • Can be used with radiators or underfloor slabs
  • Near-silent
  • Doesn’t kick up dust and allergens
  • Safe for children and animals
  • More equal distribution of heat & less heat loss through the ceiling
  • Slower to heat rooms than other home-heating methods
  • Difficult to retrofit into an existing house
  • Expensive upfront costs
  • Other types of portable forced air heaters can function as portable air conditioning as well

How much does hydronic heating cost to install?

As stated, hydronic heating is not cheap to install for both radiator and underfloor heating. Hydronic heating is expensive to install in a new home, with a new four-bedroom home costing the average Australian over $7,000 for radiators, a boiler, and installation. This doesn’t include smart systems, high-efficiency boilers, or the cost to retrofit a hydronic heating system into an existing home. If you are considering hydronic heating, whether in a new build or retrofitted into your existing home, it’s best to look at several quotes from authorised retailers as they will be able to offer additional advice or expertise.

Type of hydronic heatingHydronic heating price
Radiator$1,300 - $1,600 per radiator (boiler included)
In-slab underfloor$40 - $60 per metre squared (boiler not included)
In-screed underfloor$70 - $100 per metre squared (boiler not included)

Running cost of hydronic heating

Hydronic heating is one of the most efficient methods of heating your entire home, with average running costs comparable to that of a highly-efficient six-star gas ducted heating system. Below is an example of the estimated annual cost for different home-heating methods in Melbourne. Actual annual heating cost varies depending on factors such as where you live, your property, and the efficiency of the heating system.

Hydronic heating annual running costs
 Estimated annual cost
(100m sq house)
Estimated annual cost
(160m sq house)
Estimated annual cost
(220m sq house)
Gas hydronic
92% efficiency
$620 / year$920 / year$1,210 / year
Gas ducted
$635 / year$950 / year$1,250 / year
Electric ducted reverse-cycle
$840 / year$1,295 / year$1,750 / year
Electric multi-split reverse-cycle
$580 / year$915 / year$1,250 / year

Source: Sustainability Victoria

Heat pumps and hydronic heating

Heat pumps are a method of warming water by using the heat in the ambient air. This renewable method of heating water draws the warmth in and uses it to heat a household’s water. Heat pumps are most commonly used with domestic water supply, for showers and laundry, but in some cases it is possible to install a heat pump onto your hydronic heater, thereby reducing your energy costs even more.

It’s important to consider a few aspects first, before installing a heat pump onto your hydronic heating system, namely cost. Hydronic heat pumps are larger to accommodate the amount of water necessary to heat an entire home (consider 1kW for a domestic heat pump versus 20kW for a hydronic heat pump). In addition, a normal domestic water heat pump won’t generate hot water below 5c, while a hydronic heat pump can generate hot water until -10c. These two factors alone mean a hydronic heat pump is a very expensive piece of technology which can easily double the total installation cost of your hydronic system.

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