We’ve all experienced the limitations of traditional heating systems. Sometimes you just can’t get warm. Sometimes the front of you bakes while the back of you freezes. The dust, dry air, and sound of forced air systems can be annoying.
If you find yourself nodding your head, hydronic heating could be the answer you’ve been looking for.
What is Hydronic Heating?
Hydronic heating (also referred to as “radiant floor heating” or “in slab heating”) is an energy-efficient way to increase a building’s ambient temperature with the distribution of hot, circulating water. This creates a gentle, warming heat without many of the drawbacks of traditional heating. For the past 700 years, different forms of hydronic heating have been used all over the world.
How Does Hydronic Heating Work?
Hydronic heating is a very simple way to increase the temperature of a home, using only a few moving parts. The process can be summed up in a few simple steps.
- Water or fluid is heated in a boiler unit.
- The heated water is then circulated through a system of pipes.
- As a result, radiant heat from the hot water enters into a living space.
In some instances, the radiant heat is distributed directly from a radiator. While in other applications, the heat is able to transfer directly from the pipes to the floors, walls, or features of an interior space.
There is no limit to the size of a hydronic heating system, with small-scale single-room applications remaining just as popular as full-home or even commercial installations.
Why do People Use Hydronic Heating?
Today, most people use hydronic heating as an alternative to a traditional ducted home heating system. Hydronic heating is said to be more cost-effective, by using approximately 35% less energy. Of course, the performance efficiency of individual hydronic heating systems varies between installations.
Heated bathroom floors are one of the most popular uses for hydronic heating systems. With heat-capturing flooring materials near the hot water tank, it is generally very easy to add a small, bathroom hydronic heating system.
Full-home systems are most commonly associated with new construction or complete renovations. While it may be easy to add a hydronic heating radiator to a room, under-floor systems require significant upfront labour and considerations.
A Brief History of Hydronic Heating
Forms of hydronic heating have been used since the 1300s. The earliest recorded instance of hydronic heat is credited to a Greenland monastery, which utilized hot spring water to increase building temperatures.
Over the next several centuries, hydronic technology evolved across France and England until 1837 when a man named Charles Hood published an engineering guide with hot water heating instructions. This handbook was revised as new efficiencies were discovered.
Hydronic heating began to lose steam (pun intended) as more effective heating technologies advanced until the system was reevaluated in the 20th century. Instead of using large pipes to circulate water as quickly as possible, modern hydronic systems began to take shape in longer, thinner pipes built into a building’s structure.
The Basic Parts of a Hydronic Heating System
There are many different ways to utilize the ambient heat of hot water to control the temperature inside of a building. As technology has evolved, today’s most efficient hydronic heating systems consist of the following common parts.
The Heat Source or Boiler
First things first, the water needs to be heated for a hydronic system to work. There are many different ways in which this can be accomplished, the most common of which in Australia today is by using natural gas. Hydronic heating systems can also be powered by electricity, biofuels (wood stoves), generators, and more.
Radiant Heat Emitter
Once the water is heated, its thermal energy is then transferred to the building through a heat-emission system. Today, it is very common to install one or several radiators on the walls throughout a home. If you are using an hydronic underfloor heating system, a radiator may not be required if the heat is captured by tiles, bricks, or another masonry material.
Piping: Distribution and Return
Of course, to get from A to B, a hydronic heating system is only made possible by the pipes used to deliver the water. Sealed, safe, and durable piping is required to circulate the water between the heat source and the distribution system.
In modern homes, pipes are installed in one or more “loops” to heat different areas of the building. If you are using an old-fashioned steam hydronic heating system, pipes may not be required in the event that you are using your home’s duct system.
The heart of a hydronic heating system is the circulation pump, which is used to push the water through the pipes at optimal rates. Circulation pumps are typically electricity-powered, with innovations in efficiency continually being improved upon.
How Should You Heat the Water in Your Hydronic System?
There are many different ways that you can heat the water in a hydronic system. When considering the energy, homeowners may have the option to choose both the type of energy that they use as well as where the energy is supplied.
Gas vs Electricity
Today, the most efficient and common way to heat the water in a hydronic system is with a natural gas or liquified petroleum gas (or LPG) boiler. Although it is possible to use an electric heater, they generally consume much more energy than a natural gas heater, which negates the energy savings of a hydronic system.
Electric water heaters are most cost-effective when using an abundant, renewable energy source generated on the property.
Utility vs On-Site Energy Generation
Although you will unlikely be able to supply your own natural gas, electric heaters open the door for using on-site sustainable energy to heat your home. While we may recommend using solar hot water or a hot water heat pump to fire up your supply, it is also possible to use photovoltaic (PV) solar electricity to power a hydronic heating systems’ circulation pump.
Pros and Cons of Hydronic Heating
Wondering if hydronic heating is right for your home? Here are the comprehensive pros and cons of residential hydronic heating systems in Australia.
Quiet operation: Did you hear that? Neither did we. Hydronic systems are near silent. The only two parts of a hydronic heating system that may produce noise are the boiler and the circulation pump. As these are most commonly tucked away in the basement, you will rarely hear any part of a hydronic heating system being operated.
Energy efficiency: As we’ve alluded to above, hydronic systems are very energy efficient when compared to other full-home and partial-home heating methods. This reduces their operating costs, with the potential to save money each month on ordinary utility expenses.
Versatile options: Large and small, hydronic heating applications are not limited by any means. Individual zones within your home can be set up to be turned on or off, or set at different temperatures. Programmable thermostats can start up and shut down the system according to your individual needs. Plus, with the right system, you can even include hydronic cooling capabilities if you would like to get the most out of your system, all year round.
Long-lasting lifetime: Most high quality hydronic heating systems are designed and warrantied to last between 20 and 30 years of efficient operation.
Little maintenance required: Because they only have a few moving parts, hydronic heating systems do not require much maintenance throughout their lifetime. With routine checks and monitoring, hydronic systems only require a bit of attention every now and then.
No dust or dryness: Without the necessity of forced air from traditional heating or a heat transfer kit, hydronic heating systems are installed with several benefits for the homeowner’s quality of life. Dust is minimized, and homeowners with asthma or allergies are much less likely to run into problems at home with a hydronic heating system.
Expensive installations: More than anything else, start up costs are the most common concern with homeowners interested in a hydronic heating system. Although they are considerably less with wall-mounted radiators, full-home in-ground piping systems are very expensive to install. Between material costs and labour, some people find that a hydronic heating system is not worth it, even if they would be saving on energy costs for the next 20 to 30 years.
Potential for freezes, damages, and leaks: As hydronic heaters are a water-based energy system, there are several disadvantages that come along with that. Most commonly, this includes freezing in the winter, which can cause damage or leaks. If the system is built into your floor or wall, you may only become aware of a leak long after it has caused additional damage to your home.
Slow startup times: For the water to boil and circulate, most hydronic heating systems take a significant chunk of time to start and operate. As the radiant heat slowly fills a room, homeowners may be waiting 30 minutes to feel the effect and an hour or more for the room to reach optimal temperatures.
Tough to upgrade: If you have an existing structure, it is typically not recommended to attempt a hydronic heating retrofit system. For a system to be cost effective, it is most commonly added when a home is in the process of being built.
For those that can afford it, a hydronic system is a great way to quietly and efficiently heat a home or building. With the help of a gas or electric power system, Hydronics can deliver long-term, low-cost radiant heating for several decades.
How to Get Started with A Hydronic Heating System
Unless you are planning to do the entire thing yourself, it is very easy to find the right people to help you with your own hydronic heating system. In cities like Melbourne, Sydney, and Adelaide, there are a number of hydronic heating specific contractors ready and able to work with you on your home’s heat.
To get started, we recommend having a basic understanding of the technology and game plan in mind. You should be aware of how many rooms you would like to heat as well as the approximate cost of the system. With multiple bids and proper company vetting, adding a great hydronic heating system to your home may be as simple as signing on the dotted line.
Hydronic Heating System Designs
There are two basic designs for hydronic heating systems:
- those that radiate heat from wall mounted sources
- those that circulate hot water through the floor of a home.
Wall-mounted systems are considerably easier to install on an existing structure, while in-floor systems are best suited for new homes and buildings.
Standalone Hydronic Heating Systems
The image above shows a typical hydronic heating radiator installed on the wall of an Australian home. Systems that utilize these types of heat emitting systems can utilize one radiator or several radiators throughout the building.
There are many different types of radiators that can be used for hydronic heating, each with its own material cost, pros, and cons. Special, “designer” radiators are a great way to lower the aesthetic impact of your hydronic system with an attractive wall feature rather than a clunky metal appliance.
Radiant Floor Hydronic Heating
In-floor or “trenched” radiant floor hydronic heating systems are the most efficient way to distribute the energy throughout your home. As warm air rises, hot water circulating through the detailed network of pipes will heat your floors and radiate throughout the rooms.
Although radiant floor heating systems are typically reserved for new buildings, they can be retrofitted in bathrooms or other small instances while still being affordable. Unlike wall-mounted heaters, in-floor systems are able to evenly distribute the heat throughout a room ensuring that there are no cold spots in the home.
In this diagram, you can see the way that a typical underfloor hydronic heating system installation will work. The work begins on top of the building’s structure and an insulating layer. The tubes (or pipes) are then carefully laid across the floor, eventually being covered by the screed and top layer.
What is the best kind of Hydronic Heating System?
The best kind of hydronic heating system is largely determined by the building and budget being considered. We find that most Australian homes can benefit from a hydronic heating system in one way or another. With this, we recommend speaking to a professional before committing to any hydronic heating home plans.
How Much Does a Hydronic Heating System Cost?
Depending on the size and complexity of the installation, a full home hydronic heating system will generally cost anywhere between $3,000 and $5,000. This includes the materials and labour associated with a new building’s hydronic system
If you are going the route of radiators, the cost of your hydronic heating system will largely depend on the number of rooms you are looking to heat. On average, homeowners can expect to pay about $1,500 per room in a radiator hydronic heat system.
Hydronic Heating FAQ
Before we wrap things up, here are some answers to a few of the most commonly asked questions about hydronic heating systems.
Is hydronic heating energy efficient?
Yes, compared to other heaters, hydronic systems are among the most energy-efficient. As a result, hydronic heating systems will typically incur fewer energy costs as they run throughout their lifetime.
Is hydronic floor heating worth it?
Yes, hydronic floor heating systems are typically worth it when remodeling or building a home. For a small bathroom, kitchen, or bedroom systems and full home radiators alike, the minimal energy costs of hydronic floor heating make it a great long-term solution.
Can a hydronic heating system also be used to provide cooling?
Yes! Although this may come as a surprise to some people, modern hydronic heating systems can typically provide cooling as well. Bypassing the heat source, cool water can be circulated through a hydronic system in order to be useful all year round.
How long does hydronic heating last?
A typical, modern hydronic heating system will last between 10-20 years of efficient use. In order to maximize the lifespan of your hydronic heating system, we recommend regular inspection and servicing to ensure all of the components are in good health.
How do you clean a hydronic heating system?
A hydronic heating system is cleaned by adding a cleaning solution to the water and circulating the liquid as quickly as possible. Some circulation pumps have a “power-flush” mode to help accomplish easy cleaning. Hydronic heating systems should be cleaned approximately every 1-2 years.
Can you heat a whole house with radiant floor heating?
Yes, if you are starting from scratch, it is very easy to heat a whole house with radiant floor heating. On the other hand, if you are retrofitting an existing home, it is most possible to heat a whole house using wall radiators, rather than a floor heating system (if you find yourself in this position, it’s also worth exploring panel heaters).
Is Hydronic Heating Right for You?
With opportunities for new construction and existing buildings, hydronic heating is a great long-term solution for energy-efficient home heating. Hydronic systems can be added to heat an entire home or simply warm up the tiles in a bathroom, in an energy-efficient, cost-saving installation.
To compare your options among other efficient heating methods, feel free to check out all of our resources designed to help eco-conscious Australians make building and energy decisions.