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

Hydronic radiant floor heating

If you have decided to install a radiant floor system, you've made a good decision.

Radiant heating is an excellent option for many homeowners as it delivers better energy efficiency, savings, a luxury feel, and enhanced comfort.

But how do you determine which type is the best for your home? Hydronic or electric?

Here, we will compare electric vs. water underfloor heating, the advantages and disadvantages of both systems, and see their differences.

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

In general, radiant floor heating systems often use heated water or electricity to heat the house or a room. A hybrid option is also possible where you combine water-based and electric heating.

As opposed to forced-air systems, radiant floor systems don't heat the air directly but indirectly, increasing the temperature of the floor and surrounding objects first.

The greatest benefit of the underfloor systems is that they heat the objects first, and then radiating captured heat for a long time. The air temperature remains almost constant, eliminating discomfort at the feet level.

How does electric underfloor heating work

Electric floor heaters use loose electric heating wires positioned in a serpentine pattern or in the form of underfloor heating mats. Those heaters are installed under the tiles, vinyl, wood, or laminate floors, heating a room with radiant heat.

Electric systems come with three components: heat cables or mats, a thermostat, and a temperature sensor.

They can be installed throughout the house, but they are expensive to operate due to higher fuel costs. That is why electric heaters are often installed in one or two rooms when renovating, during home additions, and as the secondary heat source. But rarely as the primary heat source.

How does water-based underfloor heating work

Water-based underfloor heating systems use water heated by a furnace, a heat pump, or a boiler, and a circulation pump to move the water through the network of pipes, heating each part of the house equally.

The pipes are usually made of PEX and installed in a few different ways:

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

Hydronic systems are ideal for new homes and new builds and often require more planning than the electric option.

Costs and savings

Radiant floor heating systems are cheaper to run than forced-air systems because they don't waste energy by heating just the air and at high temperatures but floors and objects first, while operating at lower temperatures.

Due to its complexity, installing the radiant floor heat is the job for professionals, but DIY-ers can also do it.

Installation costs vary by location and depend on the home size, floor type, accessibility to the material and contractors, labor costs, installation type, and other factors.

Running costs will vary on the climate, home size and construction, insulation, energy costs, and temperature control.

Electric

Electric in-floor systems cost less to purchase and install but more to run than water-based systems. Yes, the operating costs are higher, but since they are used for a room or two, they are still affordable.

They heat up faster but also cool down faster.

If planning to use an electric underfloor heating system, combine it with the water systems to lower the operating costs. A great example of such a hybrid approach is when you use a water system on the main level (downstairs) and electric heating mats upstairs, where it is not exposed to cold ground.

Savings are even greater if the electric radiant floor systems are installed inside the thick concrete floor and used when the energy rates are lower. Due to the large thermal mass, a heated concrete floor would radiate the heat to the surrounding for hours.

According to forbes.com, expect to pay between $8 and $15 per square foot.

Hydronic/water

Hydronic radiant underfloor heating is one of the most popular and cost-effective systems for home heating.

They cost more to install but less to operate.

The system costs more to install than the electric type so expect to pay from $6 to $20 per sq. ft.

Installation

Electric

Electric infloor heating system

As we said before, electric in-floor radiant heating systems include only three components: a heating cable, a thermostat, and a sensor.

Heating cables often come on a spool. Since you have to position the loose cable in a serpentine pattern, fasten it with hot glue or staples, and then cover it with a thin-set or self-leveling compound, installation time might be long.

A faster approach would be to use an electric heating cable already woven into a plastic mesh, attach it to the subfloor with hot glue or stapler, apply a thin set on top and use the trowel to work the mortar into the mat. You can then install tiles on top or wait until the surface is dry and leveled to use other types of floor coverings.

The fastest but more expensive option is using solid mats enclosed in fabric, plastic, or metal foil. You just rolled them out, tape them together, and then lay the flooring over them.

Hydronic

Hydronic infloor heating system
(photo: warmup.com)

Hydronic in-floor radiant heating systems are more complex than the electric option. Water is heated in a boiler, heat pump, or water heater and runs through the network of plastic tubing - PEX, using a circulation pump.

You would run PEX under a subfloor and between joists and also install transfer plates and insulation.

Another option is to install pipes on top of the wood or concrete floor where you embed PEX pipes in the self-leveling compound or attach it to a grooved channel system.

As opposed to the electric type, where you use a thermostat for zoning, here you need electric zone valves.

As we mentioned before, electric in-floor systems are often easy to install, making them an affordable DIY home project, while in the case of hydronic underfloor heating systems, homeowners often hire a professional company to install them.

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 a region with a cold climate and a lot of snow accumulation, consider installing a radiant heating system under your driveway.

If you have a busy lifestyle or lack in physical ability to remove heavy snow, and money is not an object, it might be worthwhile investing in the driveway heating systems.

With the 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 the damaged concrete and asphalt.

Homeowners have two options to heat the driveway: electric and hydronic.

Electric radiant heat uses heavy-duty heating cables and mats designed for harsh weather and long-lasting usage. As said 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 liquid solution (such as glycol mixture) so they can withstand low outside temperatures.

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

According to the same studies, it would cost up to $250 to melt snow in winter of a 1,000 sq. ft. driveway.

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.