What is Hydronic Radiant Heat? (The Same As Normal Radiant?)

Have you ever walked into a highly cozy room, although it’s a blisteringly cold morning? There is no radiator in sight—common sense suggests it should be just as cold inside.

It might seem too good to be true, but it’s not! These conditions are the result of radiant heating. 

What is Hydronic Radiant Heat, and Is It The Same as Normal Radiant?

Hydronic radiant heating is the same as normal radiant, but it uses water as its transfer medium. The system uses the two ways heat is transferred—conduction and radiation.

It provides even heating to the entire room, operates almost noiselessly, and no vents mean clean indoor air quality, with no dust-riddled air swirling around your room.  

Types of Radiant Heating

Based on what is used to provide this warmth to rooms, radiant heat can be divided into two types: hydronic and electric. 

Hydronic Radiant Heating

Hydronic radiant heating uses water coursing through pipes fitted beneath the entire house’s surface so a boiler can heat it. It works by conduction.

The pipes are narrow and made up of polyethylene tubing that prevents the water from corroding them. The pipes can send heat from the subfloor to the room via radiation. 

Electric Radiant Heating

Electric radiant heating is a much less cost-effective option because it works on the concept of resistance heating.

The house has these wires crisscrossing the entire length of a room. When electricity is turned on, the resistance in the wires forces them to heat up, providing warmth to the room interior. However, this type of radiant heating has many drawbacks. 

It is not very cost-effective as the utility bills are sky high, so it usually only fits into one or a few rooms rather than the entire house. It does not work during power outages either.  

Components of a Hydronic Radiant Heating System

For the system to work effectively, its components must run smoothly.

The elements of a hydrogen radiant heating system are as follows.

Boiler

A boiler or a source is the core of your entire heating system. It uses fuel to heat the water in the pipes before it is sent to warm the rooms. 

The boiler is usually placed in a room with a central placement in the house, usually the basement, so it can adequately supply heated water to all parts of the house.

Ideally, a boiler should be highly efficient, so the maximum amount of heat can be conducted in the pipes. 

Based on the fuel source used to provide the heating, there can be tankless water heaters, combined boilers, solar water heaters, or heat pumps (geothermal energy).

Medium

A medium is a substance that circulates in the pipes and transfers the heat to the surface for heating. In a hydronic system, the transfer medium is water. 

Sometimes people also prefer to use other mediums such as oil or antifreeze mixtures such as glycol in frigid climates. However, water is still the most common transfer medium because of accessibility.

Thermostat

The number one selling point of radiant heating is its uniformity during heat transfer, and the thermostat strikes a balance.

It senses temperature and automatically turns heating on or off according to the room’s temperature setting. A constant and even heat is conducted, despite the system constantly turning on or off.

Manifold

A manifold is a focal point in the branching system of the pipes, which is directly connected to the thermostat. Heated water from the boiler is directed wherever the manifold needs it.

Tubing

The tubing of the pipes is made using cross-linked polyethylene (PEX) or some other form of industrial-grade plastic. The PEX is easily flexible in directing the water flow, and the pipe doesn’t corrode, a problem often faced by hydronic heating system users in the past.

Heat Exchanger

A heat exchanger works by radiating the heat from the pipes to its ultimate destination—the room’s interior.

There can be a lot of variation in the positioning of heat exchangers during their installation. For example, they can be placed under the floors, on the ceiling, inside the walls, or on the baseboard. Depending on its placement, different levels of warmth are provided. 

Radiant floor heating is a hydronic heating system’s most common type of heat exchanger. However, it is most conveniently installed during the construction of the house and can be difficult to install after a home has been built.

The Pump

Water needs to be pumped constantly to maintain and restore its supply. When sufficient water passes through the pipes, adequate amounts of heat can be transferred.

What Sets a Hydronic Radiant Heating System Apart?

Several benefits set hydronic radiant heating systems apart from other heating options.

These advantages include:

Energy Efficiency

The main reason the hydronic heating system is more efficient than air-based heating boils down to fundamental physics—water is a better conductor than air. Water has more than 3,000 times the capacity of air to transfer heat. 

In a forced-air heating system, the air is heated and blown into the room, immediately rising to the ceiling instead of reaching the floor. Therefore, it cannot provide the same warmth and comfort as the hydronic radiant heat near the floor.

Since hydronic radiant heating is nearer to your feet, the system can more easily reach a matching comfort level at a lower temperature.

These factors add up to a lot and significantly impact your overall energy expenditure.

Eco-Friendliness

The burning of fuels is directly related to the emission of greenhouse gases. As the hydronic heating system consumes less energy, it is eco-friendly and emits less CO2.

Zonal Heating

The pipes in each space are installed in ‘zones.’ Each zone has a separate thermostat, ensuring that energy can be utilized where it is needed rather than being wasted to heat corners of the house that are not in use.

Renewable Heat Source Possibilities

You can provide a sustainable heating source to increase the efficiency of a system even more. Geothermal energy and solar energy are the two sources currently being employed.

Cleaner Indoor Air Quality 

The traditional forced-air heating system drives air from the outside to the inside of the room. This system largely depends on the atmosphere and can bring in dust, smoke, or allergen particles that have escaped the air filter. 

Hydronic radiant heating only warms the inside air, which is clean. Plus, you don’t have to go through the trouble of installing, cleaning, or maintaining air ducts and filters. 

Balanced Heating and Atmosphere

Unlike a traditional heating system, there is no constant passing of air. It guarantees even heating throughout the room while the interior’s atmosphere (humidity, pollutants, other gases) remains undisturbed. 

Cons of Hydronic Radiant Heating

Despite the numerous advantages of a hydronic heating system, nothing is without a few drawbacks. Therefore, it is crucial to weigh the pros and cons before making any decision.

High Initial Cost

Hydronic radiant heating is the most expensive type of heating system yet. Depending on the installation method, it costs between $6-$15 per square foot. 

Although it gives excellent energy returns (30% more efficient than any traditional heating system), the higher upfront cost cannot be managed by everyone. 

Longer Heat-Up Time

Although water is a better conductor than air, it still needs to travel the entire system length before it can transfer the heat. Although separate zones have mitigated this problem, the initial heating time remains prolonged.

Space Requirements

Hydronic radiant heating best in a house or building with a lot of space. It requires the placement of a boiler, preferably in a centrally placed boiler room. Pipes can also take up space inside your home. It can be problematic for people who don’t have extra space to spare. 

Accessibility and Maintenance

Hydronic radiant heating works best when installed under the floor. While floor heating has many advantages, it can cause many problems if the system gets damaged since it is not easily accessible. Homeowners must tear off the floor to make the necessary repairs, which requires additional cost. 

Final Thoughts: Is Hydronic Radiant Heating Worth It?

Radiant heating dates back to ancient Roman times; however, technology has developed a much superior hydronic radiant heating system. It runs on the basics of physics and is a sustainable option that is eventually light on your pocket.

Besides, any heating system that eliminates the need for a radiator that sounded ready to take off into space is welcomed readily into the modern world.

So get ready to receive an unmatched level of comfort during the long weeks of winter that’ll not just warm your feet but also your heart.