Electric vs. Water Underfloor Heating: Differences, Advantages, and Disadvantages

Hydronic radiant floor heating

When deciding between electric vs. water underfloor heating for your home, you've made a wise choice to consider a radiant floor system. This type of heating offers improved energy efficiency, cost savings, a luxurious feel, and enhanced comfort.

However, choosing the right system for your home can be a challenge. Should you opt for a hydronic or electric option?

In this article, we will compare electric and water underfloor heating systems, highlighting the advantages and disadvantages of both options, and examining their differences. By the end of this discussion, you'll be better informed to make an educated decision about which option is the most suitable and cost-effective for your home.

In this article

1. Comparing pros and cons: Highlights
2. How do they work
3. Costs and savings
4. Installation
5. Advantages
6. Disadvantages
7. Heated driveways

Comparing electric vs. water underfloor heating: Highlights

Hydronic vs. electric radiant floor heating: How do they work

Radiant floor heating systems typically use heated water or electricity to warm a room or a house. It's also possible to have a hybrid option where you combine water-based and electric heating.

Unlike forced-air systems, radiant floor systems do not directly heat the air. Instead, they indirectly heat the floor and surrounding objects first, raising the temperature in the room.

One of the key benefits of underfloor systems is that they heat objects before radiating the captured heat for an extended period. This method maintains a consistent air temperature, eliminating discomfort at the feet level.

How does electric underfloor heating work

Electric floor heaters use electric heating wires that are positioned in a serpentine pattern or in the form of underfloor heating mats. These heaters are installed beneath tiles, vinyl, wood, or laminate flooring to warm a room with radiant heat.

The electric heating system consists of three components: heat cables or mats, a thermostat, and a temperature sensor.

While electric systems can be installed throughout the house, they are expensive to operate due to high fuel costs. For this reason, electric heaters are typically installed in one or two rooms during renovations, home additions, or as a secondary heat source, but rarely as the primary heat source.

How does water-based underfloor heating work

Water-based underfloor heating systems use water that is heated by a furnace, heat pump, or boiler, and a circulation pump to move the water through a network of pipes. This system heats every part of the house evenly.

PEX pipes are typically used for water-based underfloor heating systems, and they can be installed in various ways, including:

• Laid under the floor and on top of the subfloor (with a thin slab).
• Stapled up underneath the subfloor.
• Within a concrete floor.

Hydronic systems are an excellent option for new builds and require more planning than electric options.

Costs and savings

Radiant floor heating systems are more cost-effective to operate than forced-air systems because they don't waste energy by heating just the air at high temperatures. Instead, they heat the floors and surrounding objects first, while operating at lower temperatures.

Due to the complexity of installation, it's recommended to have professionals handle the installation of radiant floor heating systems. However, DIY enthusiasts can also attempt it.

Installation costs vary depending on factors such as location, home size, floor type, accessibility to materials and contractors, labor costs, and installation type.

The running costs of a radiant floor heating system depend on factors such as climate, home size and construction, insulation, energy costs, and temperature control.

Electric

When compared to water-based systems, electric in-floor systems are cheaper to purchase and install, but more expensive to operate. However, since they are typically used for a room or two, they are still an affordable option for many homeowners.

Electric systems heat up faster but also cool down faster than water-based systems.

To reduce operating costs, a hybrid approach can be used, combining electric and water-based systems. For example, a water-based system can be used on the main level (downstairs) and electric heating mats can be used upstairs, where the floor is not exposed to the cold ground.

Savings can be even greater if electric radiant floor systems are installed inside thick concrete floors and used during periods of lower energy rates. Due to the large thermal mass, a heated concrete floor can radiate heat for hours.

According to forbes.com, homeowners can expect to pay between $8 and $15 per square foot for electric in-floor systems.

Hydronic/water

Hydronic radiant underfloor heating is a popular and cost-effective option for home heating, although it costs more to install than electric systems, the operating costs are lower. The installation costs typically range from $6 to $20 per square foot.

Installation

Electric

Electric infloor heating system

As mentioned previously, electric in-floor radiant heating systems consist of only three components: a heating cable, a thermostat, and a sensor.

Heating cables often come on a spool and must be positioned in a serpentine pattern, fastened with hot glue or staples, and covered with a thin-set or self-leveling compound, making installation time-consuming.

A quicker installation method is to use an electric heating cable woven into a plastic mesh, which can be attached to the subfloor with hot glue or staples. Then, a thin set can be applied on top, and a trowel can be used to work the mortar into the mat. Tiles can be installed on top, or other types of floor coverings can be used once the surface is dry and leveled.

The fastest but pricier option is using solid mats enclosed in fabric, plastic, or metal foil. These mats can simply be rolled out, taped together, and then the flooring can be laid over them.

Hydronic

Hydronic infloor heating system
(photo: warmup.com)

Hydronic in-floor radiant heating systems are more complex than electric options. These systems require water to be heated in a boiler, heat pump, or water heater and then circulated through a network of plastic tubing, typically PEX, using a circulation pump.

To install hydronic systems, you would run PEX tubing under a subfloor and between joists while also installing transfer plates and insulation. Alternatively, you can install pipes on top of the wood or concrete floor and embed PEX pipes in the self-leveling compound or attach them to a grooved channel system.

Unlike electric systems, which use a thermostat for zoning, hydronic systems require electric zone valves.

While electric in-floor systems are often easy to install, making them an affordable DIY home project, homeowners typically hire a professional company to install hydronic underfloor heating systems due to their complexity.

Advantages

Like other types of HVAC systems, hydronic and electric in-floor systems also have a number of pros and cons, which you should consider carefully to make the right decision.

Electric

• Evenly heated home
• Fast heating (quick response time)
• Great for spot heating and retrofits
• No cold feet
  
• Easy DIY installation
• No maintenance required
• Improved air quality
• Increased comfort
• Works with any floor type
• They offer independent controls to each room
• Easy to track where the damage is and fix the problem

Hydronic/water

• Lower heating costs
• Even heat distribution
• Great for new builds
• No cold spots
• Low maintenance
• Easy control using smart thermostats
• Better air quality
• Better comfort
• It can be installed anywhere
• It can be used for both heating and cooling

Disadvantages

Electric

• Due to higher energy costs, these systems are not cost-effective when used for the whole house heating
• It is used only for heating
• If you want to install an electric infloor system in your existing room(s), you will need to replace flooring

Hydronic/water

• Higher purchase cost
• Greater installation cost
• It takes longer to install
• It takes longer to heat the space
• Not suitable for spot heating
• It requires some maintenance
• Hard to pinpoint the exact location of the leak
• Costly repairs
• It can cause home damage if water leaks from the pipes
• If you want to install a radiant heating system in your existing home, you will need to replace flooring

Heated driveways

If you live in an area with a cold climate and significant snow accumulation, you may want to consider installing a radiant heating system underneath your driveway. This is especially true if you have a busy lifestyle, lack physical ability to remove heavy snow, and have the financial means to invest in such a system.

With heated driveways, the entrance and parking area would be clean from snow and ice buildup, significantly reducing the risk of slips and falls.

No more shoveling the driveway, paying snow removal companies, or dealing with damaged concrete and asphalt.

Homeowners have two options for heating the driveway: electric and hydronic.

Electric radiant heat uses heavy-duty heating cables and mats designed for harsh weather and long-lasting usage. As mentioned before, the advantage of such systems is faster response time, but the cost is higher.

According to some studies, it would cost up to $692 to heat a 1,000 sq. ft. slab in regions with average snowfall.

Hydronic heating systems use strong and durable PEX tubing filled with a liquid solution (such as a glycol mixture) so that they can withstand low outside temperatures.

These systems have lower operating costs, but the installation cost is higher, and more maintenance is required.

Based on the same studies, melting snow on a 1,000 sq. ft. driveway during winter would cost up to $250.

Both systems are embedded beneath the surface of the driveway, and when installed correctly, they can last over 15 years, delivering reliable service.

So, what is better, water or electric underfloor heating?

Whether you choose a hydronic or electric underfloor heating system, you will get the best heating system for your home.

Both water-based and electric in-floor systems are reliable and effective in providing radiant heating. They are hidden under the floor for better aesthetics, operate with no or little maintenance, and provide increased comfort.

The main differences are found in the purchase and running costs, installation process, and the time needed to heat the floor.

Electric underfloor heating is better for spot heating when renovating a room or if you want to add heating to a specific room. Hydronic in-floor systems are perfect for heating new homes.