Retrofitting Radiant Heat in a Home Remodeling Project

Installing Radiant Heat When Remodeling

Radiant heat can be an efficient way to heat your home or a space in your home. If you're considering adding a radiant heat or cooling system to your home, unless you have particular constraints, you're most likely looking at a hydronic system. Hydronic systems use water as the heating and cooling element.

Radiant heating is an excellent addition to your home remodeling project. Hydronic systems consist of plastic tubing run through tubing installed under your finished floor. Installation of a radiant system during a renovation project is a cost-effective way to add a superior heat source to your home. However, it is possible to install a radiant system as a retrofit to your existing space.

Retrofitting A Hydronic Radiant System In Your Home

Curious about zoned heating and cooling, or radiant floor heat? I'd love to try to answer for you!

Adding a hydronic system to your home can often help you to save energy and increase your comfort. It's important to consider several factors in your home's current systems to ensure above-average efficiency. If you live in an older home and has poor or standard energy efficiency, radiant heat may not provide sufficient heat. If your house is not particularly well insulated, you may not ever receive a return on your investment.

Your design-build-remodeler can help you understand the effect radiant heating and cooling will have on your energy consumption based on an analysis of your homes thermal envelope.

If your home has more efficient heat production systems, for example, a heat pump, or a solar water heater you can reap even more savings and cut your energy use even further. To improve efficiency, the thermal conductivity of your flooring is essential. Materials like tile and concrete work best, but there are systems that will work adequately with wood flooring. Look for layered engineered wood as opposed to solid wood for the highest-efficiency.

The Installation Process

If you're retrofitting an existing floor, the best approach is to install the system from below to the underside of the subfloor. It can go under most existing types of flooring including wood, vinyl, tile and even carpet but once again, your floors ability to conduct heat will contribute to the efficiency of the system.

Installation begins by attaching aluminum tracks placed between the joists which hold PEX tubing carrying hot water. PEX isn't a great thermal transfer medium which is why the aluminum tracks are used. They transfer the heat from the PEX and conduct it to the subfloor. The tracks also work to keep the tubing evenly spaced to avoid cold spots. The tubing snakes from joist to joist through holes drilled through the joists.

Insulation around the tubing is critical to ensuring efficient heat transfer directed up into the floor. Typically, spray foam is used between the joists over the tubing. This forms a tight seal. Fiberglass batts and rigid foam can also be used.

Installing radiant heat on a second floor is a bit more challenging. There is rarely access from below without removing the ceiling, so the tubing must go above the subfloor and can add 1/2” to 1 1/2” to the floor grade. Fortunately, there are products that can keep the height below 3/4”. Panels can go over any type of subfloor including planks, plywood OSB or concrete as long as it is level and sound.

A radiant system needs hot-water supply. A decade ago, this was done by adding a secondary, dedicated loop to the domestic hot water heater. (No drinking water is ever mixed with the heating water.) More often, a dedicated boiler is installed.  The most common boilers used by our clients are high-efficiency condensing boilers that run at around 98% efficiency. This is significantly more energy efficient than using the dedicated water heater loop, which typically only runs around 65% efficiency.

A Word About The Electric Alternative

Electric radiant systems work best in a single room or smaller space. Cables are installed in the floor, in thin mats or in fiberglass netting. While installation costs are lower and installation times faster, electric radiant systems do not make good economic sense in larger spaces like a living room or kitchen, especially in colder climates. They are expensive to operate. Evaluate whether you are prepared to pay a large upfront price for lower long term cost of operation, or, if you will happily pay the larger monthly bill in exchange for a lower initial cost of installation.

Hydronic systems are efficient because they use water which is the perfect transfer medium.

Taking the First Step

If you're considering adding an efficient hydronic radiant heat system to your home, speak with an energy-efficiency consultant, architect or design-build-remodeling contractor who has experience performing a feasibility study to make sure that a radiant system will have a positive impact on your home's overall energy efficiency. Next, request a design proposal and get a quote.

Nothing feels more luxurious than stepping onto a warm floor on a cold winter morning. Retrofitting your home with a hydronic system can pay for itself over time through lower energy use and lower utility bills. Plus, the return on investment regarding your lifestyle and comfort is 100 percent!

Are you considering a home remodeling project in Greater Madison, Wis? We are a team of expert design-build-remodelers and we want to hear from you. Click here to schedule an appointment.

This article was updated by Abe Degnan on 6/25/2018.

About Degnan Design Build Remodel
Since 1981 Degnan Design Build Remodel has provided home improvement and construction services to customers throughout Greater Madison, Wisconsin. Our goal is to WOW you with a "Designed For Your Life" solution using a process that will transform your home into a beautiful living space, delivered on time, and on budget. We are known for our communication, respectfulness, and a commitment to our customers and our community. Contact us to speak with one of our designers about your home improvement project.