Ancient, Efficient, Practical, and Cozy
** Updated July 6th, 2022. Originally posted March 9th, 2022.
John Webb has been a highly reputable new home builder in Eugene Oregon for 20 years. The John Webb Construction & Design team are well known for building new energy efficient homes. The literal foundation of his reputation starts with Radiant Heat floors. Learn about the history and design principles of radiant heating and cooling.
What exactly is Radiant Heating and Cooling? Or, if you happen to know what it is and find that there really is no better way to heat and cool your home, your question is likely: Why isn’t it more common?
A heating and cooling system is considered radiant if it’s heat exchange is over 50% radiation. Baseboard heaters for instance, radiate a lot of heat, require a ton of energy, and are so inefficient that the gradual convective action (90%) has to fill the room from the top down to provide comfort. Radiant Heating and Cooling uses efficiently placed, larger radiators of varying types (Electric, Infrared, and Hydronic) to create and utilize a larger thermal mass for the heating and cooling of a space. There are a surprising number of fascinating design options for Radiant Heating & Cooling for indoor & outdoor commercial and residential applications. For this post we will focus on hydronic residential underfloor systems and give a quick overview of the history of this technology.
Residential Underfloor Radiant Heat systems often use Hydronic technology. Hydronic Radiant Systems use temperature-controlled water that is pumped through hundreds of feet of pipes and tubing. Hydronic Systems tend to be of two types:
More precise temperature control is the most obvious benefit of a well designed radiant heating and cooling system. Your standard forced-air system rely’s on a thermostat that is mounted chest-level on an interior wall. This means that the air at 4 feet is at 70 degrees while the air below the thermostat is cooler. A Hydronic system controls the temperature of the water inside the floor itself, making micro-adjustments to the boiler output, distributing that water out through several pumps to the different zones within the system, ensuring that the entire home is warmed (or cooled) from the floor on up. This allows you to set your temperatures lower to achieve your standard of comfort.
The history Radiant Heating is actually quite surprising. Accomplished Modernist Architects and Developers like William Levitt, Joseph Eichler and of course Frank Lloyd Wright, helped to popularize Radiant Heating and Cooling systems in the West. When they were integrating these rather practical ideas into their residential designs it was believed that Radiant Heating & Cooling in architecture was possibly 1000 -1500 years old. It turns out you have to travel as far back as 10,000 BCE, to China and the Korean Peninsula, to understand it’s origins.
Originally, a rudimentary version of these systems, called Ondol, included flukes running through a home’s foundation, heating the home. Written evidence refers to these designs as far back as 10,000 BCE. There is archeological evidence of a handful of dwellings that contained a version of these designs between 5000 and 1000 BCE in China, the Korean Peninsula, and as far out as the Aleutian Islands in Alaska.
For most of the 20th Century, before the technology was there, when residential development was less concerned with the health and safety of residents, a number of mistakes were made in designing and installing these systems. In the late 70’s poorly designed Radiant Heat systems that used coal and flue gas in apartment buildings in Korea, resulted in death and sickness. Such tragedies inevitably led to higher regard for safety and the need for technological advancements and reconsiderations. Over the course of the 1980’s it was established that Hydronic Systems were the safest and most efficient option for Radiant Heating & Cooling.
John Webb’s standards when building his signature energy efficient homes starts with a Radiant Heated, polished concrete slab. When exactly did this become John’s foundation of efficiency?
In the late 70’s, while John was gaining Architecture & Design experience in Terra Linda, California, he lived in an Eichler Home. Joseph Eichler, a renowned modernist developer, designed quite a few homes in the San Rafael area with walls of glass, open-beam ceilings, and radiant heat floors. Living in such a unique home at the beginning of his career, John was able to see the stylistic and practical appeal of those design choices, and picked up on the clear differences between forced air and radiant heated homes.
The Architecture & Design Firm John worked for built homes in Lake Tahoe and Park City, Utah, all with Radiant Heating. Seeing how well these residential heating systems performed in such cold environments really sold John on the technology. You really can’t argue with warm feet on a bare floor, a significantly lower heating bill, a silent heating system, and not having to deal with the dust that forced air systems draw in and kick around your home. Once John was designing & building homes for clients, he knew radiant heat systems would be the right choice for nearly all of his clients.
Radiant Heat systems help to create a far healthier home environment in several ways.
Radiant Heating & Cooling systems have become quite advanced over the last 40 years. Considering that these systems are installed for reasons of energy efficiency, health, and comfort, they often work in conjunction with air filtration, dehumidification, and central air systems. For hydronic systems, in the warmer months, to run cooler water through your foundation will drastically cut down on the output needs of your AC system. There are of course limitations to any technology. Depending on the average relative humidity and overall climate of where you live, your heating and cooling needs will vary. The nearer you are to the equator the greater your reliance on your hydronic system’s cooling. Due to the resulting condensation from more extreme system settings, you will need a more robust dehumidification system.
“Gosh I think it must have been back in the late Seventies, I had lived in Terra Linda California, in an Eichler Home which is all walls of glass and open beam ceilings – very simply built – and they all had radiant heat floors. That was really my first experience living in it and having that in the winter time. I really loved the way that the heat was all even and silent with no dust in the whole thing.
That is something that I really had to design into my own buildings when I went out on my own. When I was working in the Architecture and Planning Firm we used Radiant Heat designs when we built homes up in Lake Tahoe and Park City Utah. They were all Radiant Heat since they were in a much colder climate. Almost all the homes I’ve built have that option in them.
You know, they’re really very healthy homes. They don’t have all of the dust blowing around that more conventionally heated homes have. It’s nice for dogs running in and out in the wintertime, the floors dry, and you just dust it, or sweep it up. Whether they come in with muddy feat it doesn’t matter, it dries quickly and you just use a dust mop or vacuum and clean it right up. It’s wise.
It’s just a different kind of heat. All your forced air thermostats are at about 4 feet high, so if it’s set for 70, everything above it is 70 degrees and everything below it is cooler. So, the difference is that the heat is coming from under your feet so you can set your thermostat lower and it’s even. You don’t have any cold spots. Say you have walls of glass, it’ll be an even heat throughout the entire place.
And we’ve gotten a bit more sophisticated with it. All our shower floors are radiant heated. In the Summertime the floor is cooler – the cool air created by the concrete slab stays closer to the floor, which seems to me and is proven by your electricity bill, that it’s more energy efficient that way. It’s cooler when you want it in the Summer and it’s really warm and nice and cozy in the Winter.”
Written by Todd Zimmerman
Producer of the John Webbccast