radiant floor cooling tubes installed in an exposed floor

Heating, ventilation, and air conditioning (HVAC) systems cool a building by circulating air throughout the space. Radiant floor cooling is a new technology that aims to create a conducive indoor environment by cooling the floor. 

As a new construction technology, many people often wonder how a radiant floor cooling system works and whether it’s practical.  

This article will discuss radiant floor cooling systems and how they compare to other cooling systems. We’ll also touch on the pros and cons of of this home cooling technology. 

So, let’s get started!

What Is Radiant Floor Cooling?

Radiant floor cooling is a system that uses water to cool the floor and circulate the cooled water throughout the space, providing a comfortable indoor environment. It incorporates water-filled tubings embedded in the floor or grooved panels placed over it for cooling purposes.

The Workings of Radiant Floor Cooling

Modern technology provides various heating and cooling solutions for homes. Your responsibility is to choose one that best meets your unique needs. Among the options is radiant floor cooling.

According to Energy Saver, a radiant floor cooling system absorbs the heat radiated from the floor and transfers it to cold water in a closed loop. The water is then cooled by either an air-cooled or water-cooled chiller and circulated back to the floor.

The system can also be integrated into a hydronic heating system, which uses hot water to heat the floor.

It’s worth noting that radiant floor cooling does the opposite of radiant floor heating. While the latter works by circulating hot water through tubing to heat the floor, the former circulates cold water to cool the floor.

Glycol is usually mixed with water in the radiant floor cooling system due to its high viscosity and low heat transfer. These characteristics help prevent condensation on the floor.

Chilled Slabs Radiant Floor Cooling Systems

Chilled slab radiant floor cooling systems, also known as thermally-activated building systems (TABS), is the most common type of radiant floor cooling.

They circulate chilled water between 55-58°F (12.78-14.44°C) through piping embedded in a concrete slab or gypsum underlayment. The heat from the floor is transferred to the water, cooled, and recirculated back to the floor.

An old school radiant flooring system partially covered by wood panel flooring

These slabs use tubes with a close center spacing between six and nine inches (15 and 23 cm) for efficiency. Such spacing makes it easier for the system to radiate heat from the room by enabling fluid compaction.

Chilled slabs are especially beneficial in summer or in places with high solar. When there is a high amount of solar gain penetration from the sun, the chilled slabs on the floor absorb and radiate it to the cold water.

The main advantage of chilled slabs is that they provide uniform cooling throughout the space. This feature is because the entire floor surface acts as a heat sink, providing an even distribution of cool air.

Moreover, chilled slabs offer a more significant thermal mass, which adjusts well based on the daily temperature swings to cool the room.

Installation of Radiant Floor Cooling Systems

Radiant floor cooling systems are installed in two ways including:

  • Using pre-made panels or tiles
  • Installation of radiant cooling lines

Pre-Made Panels or Tiles

This is the most common approach used to install radiant flooring systems. Most engineers and contractors prefer this approach because it makes the process easier.

In this method, unique panels or tiles are fitted in the already-installed cooling lines. These panels or tiles are then laid over the floor surface.

The main advantage of this approach is that it’s quick and easy. Moreover, it doesn’t require any changes to the existing structure of the floor.

The main downside of this approach is that it’s expensive since the panels or tiles typically consist of more costly materials. Furthermore, they may not fit your desired stature as the panels are pre-made and not customizable.

Installation of Radiant Cooling Lines

This method installs radiant cooling lines directly into the floor surface during construction. The contractor only pours the concrete after installing the cooling lines to create a slab over them.

Alternatively, you can install the cooling lines on top of an existing slab. In this case, additional concrete is required to cover the lines.

A technician kneeling on the floor cuts a piece of cable from a spool during a radiant floor heating system installation

The main advantage of this approach is that it’s more affordable. This cost-effectiveness is because you don’t have to buy special panels or tiles. Moreover, you can install the cooling lines to your desired stature.

The main downside of this approach is that it’s more time-consuming because the installation process is more complex and requires more skills.

It’s also worth noting that this approach may not be feasible in all cases. For example, if you’re retrofitting an existing building, it may not be possible to install the cooling lines without causing damage to the structure.

Using a professional to install the cooling lines is essential to eliminate errors. A professional like a contractor will assess your house to determine the most viable approach.

Some of the crucial factors considered in the assessment are:

  • The size of your house
  • The type of flooring you have
  • Your budget

After the assessment, the contractor will quote you for the installation. The quote will include the cost of materials and labor. Getting multiple quotes from different contractors is essential to ensure you get the best deal.

How To Use Radiant Floor Heating To Cool a House

You may have installed a radiant floor heating system for the winter, and now the weather has changed—it’s summer, and the excessive indoor heat makes your house intolerable. 

You can use your radiant floor heating system to cool your house in the following two ways:

Setting the Heat Pump To Cool the Floor

Some radiant floor heating systems have pumps designed in a way that they can be set to cool instead of heating the floor. Such pumps come with a thermostat that can be used to set the desired temperature.

Your role is to adjust the thermostat in relation to the outdoor temperature. Be sure to set a lower temperature than that of outside.

Adding the Radiant Floor Cooling System

You’ll have to go a long way if your radiant heating pump is not adjustable. For this option, you’ll need to install a radiant cooling system. It involves installing separate cooling tubes, a cooling system, or a chiller.

The cooling system will help regulate the floor’s temperature and circulate cool air in the house. It’s important to note that this option is more expensive than setting the heat pump to cool.

You need to hire a professional for this process as it involves assessing the type of floor to get suitable tubes, slabs, or panels. Additionally, you’ll have to make structural changes to the floor to accommodate the new tubes and the cooling system.

Closeup on some lines of chilled slap radiant floor cooling

How To Deal With Condensation Due to Radiant Floor Cooling

The main challenge with radiant floor cooling is humidity and condensation on the slabs. These factors expose your house to water damage and mold if left unchecked.

It’s your responsibility to develop a way of dealing with humidity and condensation, failure to which your home risks water damage and mold formation.

When using a radiant floor cooling system, condensation happens when the room’s air dew point is lower than the floor’s surface temperature. In most cases, this happens on humid days.

It’s not advisable to open the door and windows when you notice dew forming, as this introduces more humidity into the house, increasing condensation.

Modern radiant floor coolers have dew point sensors that help regulate the system. The sensors are designed to detect when dew is about to form so the system can take the necessary action.

For example, the sensor can increase the surface temperature or reduce humidity.

Another way of dealing with condensation is using a floor heating system with an integrated humidifier. The humidifier will help regulate the level of humidity in the house.

A homeowner using a smartphone to adjust her dehumidifier's settings

Alternatively, you can install a separate air handling system. The system will be responsible for removing latent moisture load from the air. It will also help improve overall ventilation to ensure a conducive indoor environment.

Arctic Heat Pumps in Radiant Floor Cooling Systems

Arctic heat pumps are known for their efficiency in radiant floor heating systems. However, these pumps are excellent in dealing with slab condensate in radiant flooring.

Arctic heat pumps have a dew point switch that makes it hard for moisture to form on the floor. The dew point switch in these pumps incorporates the REESOL TS510 design that works as a moisture controller in radiant floor cooling systems.

Radiant floor systems have a dew point sensor whose work is to detect condensation in the pipes. Once the sensor detects it, it alerts the dew point switch controller. The controller then adjusts the slab’s input temperature.

The arctic heat pumps come in to sustain slab temperature that will prevent condensation. They achieve this by cooling the water in the buffer tank. Once the water is cooled, the controller can tap heat from the subfloor.

The heated air is then sucked into the floor tubings and dissipated into the slabs, preventing condensation. This way, there will be no point when your floor forms a condensate due to radiant floor cooling, provided there is no fault in the entire system. 

The dew point sensor will always notify the controller in case of slight condensation to initiate corrective action.

Radiant Floor Cooling vs. Air Conditioning

Radiant floor cooling and air conditioning are systems used to cool a room. However, they achieve this goal differently.

The table below illustrates the key differences between radiant floor cooling and air conditioning systems:

Radiant Floor CoolingAir Conditioning
Cools the room by circulating cold water through tubes installed on the floorCools the room by circulating cool air using fans and blowers
Operates by cooling the floor surfaceOperates by cooling the room’s air
Cools the entire room since the tubes are installed throughout the floorCools specific locations in the room since the fans and vents are installed at select points
The system takes time for the cold air to be felt since the heat pump must be activated to circulate the hydronic fluidWorks immediately once switched on to create a cooling effect

Table 1: Differences between radiant floor cooling and air conditioning

Pros of Radiant Floor Cooling

  • Energy-efficiency – radiant floor cooling systems save up to 30% of energy compared to air conditioning systems. This saving is possible because these systems don’t use energy-intensive fans and ducts. 
  • Quiet operation – unlike air conditioners that produce a considerable amount of noise, radiant flooring operates quietly. As a result, you’ll only hear water flowing through the pipes.
  • Even cooling – radiant floor cooling systems provide an even distribution of cool air in a room. The systems don’t have cold spots like air conditioners.
  • Humidity control – radiant floor systems help regulate a room’s humidity level. The lack of blowers, fans, and vents means there is no recirculation of allergens. Such a system is ideal for people with respiratory problems like asthma and potentially severe allergies.

Cons of Radiant Floor Cooling System

  • It’s expensive – installing radiant floor cooling is costly compared to air conditioning. With radiant floor cooling, you have to buy the tubes, pump, and cooling system. You also have to hire a professional to assess your house for installation.
  • Incompatible with thick carpets – radiant flooring is only effective on hard floors like concrete, tiles, and wood. A carpet acts as an insulation that hinders the operation of the cooling system.
  • Costly repairs – you must rip out the floor to repair broken tubes, which translates to additional repair costs (both the tubes and floor).

Final Thoughts

Radiant floor cooling uses specially-mounted panels or tubes beneath the floor to provide a cooling effect. The system is energy-efficient and highly recommended as it cools everywhere the lines are installed.

However, radiant flooring has its fair share of pros and cons. Some of the notable disadvantages include the high installation and repair costs.

We hope this article equipped you with the knowledge to decide if this technology suits your home.

Best of luck!


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