Radiant Floor Expert

Mon, February 02, 2017

[caption id="attachment_194" align="alignnone" width="675"] radiant flooring[/caption] With the current frenzy over "green" products lately, I thought I would give some well deserved credit to a product that really stands out in the "green" market. That product is nothing more than hydronic radiant floors. That's right, no cutting edge technology, no sexy gimmick, just a well designed and installed hydronic radiant floor. In this article I want to talk about what it means to be a 'green' product, at least in my eyes, and also explain why hydronic radiant is quite possibly one of the greenest products available. When we think of HVAC systems and the "green," eco-friendly options we have to choose from, we quite often think of geothermal systems, solar heating, condensing boilers, VFD controlled pumps and fans and many other highly efficient products. But what is truly important to me is not the device itself, but rather the way you apply it to an actual system. For example, if you run a condensing boiler in a system with a return above 130 F, you will not benefit from the efficiency capabilities. What needs to be looked at when thinking "green," is not just a single device, but the system as a whole. Hydronic radiant floor systems have many aspects that can contribute to the overall system efficiency. These aspects are what allow the so-called 'green' products shine. It is not surprising then, to see why Frank Lloyd Wright, known for his "Organic Architecture," helped to popularize radiant floor heating in the 1940's. A radiant system works by sending hot water through tubing in the floor, which heats the floor surface to 72-85 F. Forced air systems heat air to around 120 - 140 F and circulate it through duct work. The hot air then enters the space and keeps the air temperature around 72 F. A common misconception is that heat rises, which is incorrect because heat goes from hot to cold, in any direction. What is important here is that hot air rises, not just heat. So, when you heat air, like in a forced air system, the hot air will rise to the top of the building, away from the occupants. Radiant floors do not work in this way. Radiant floors transfer heat to the objects and people in the space. This allows for a lower design indoor air temperature, usually 68 F. When compared to a forced air system, a typical residential system will be about 10-30% more efficient, while a commercial hanger or warehouse can see savings up to 60%. The next aspect we need to look at is supply water temperature. A typical in-slab or sandwich style radiant installation will require about 120 F supply water temperature, on a design day. This is worth mentioning because the low water temperature is what allows a condensing boiler to get its high efficiency. Even a non-condensing boiler will produce better overall system efficiencies if properly designed with a mixing control. Geothermal systems that have a limit of 130 F supply water temperature can be utilized 100% of the time on a low temperature system. The key here is that the radiant floor system is what allowed the heat sources to be highly efficient, not the other way around. Another great quality of radiant floors is the ease in which they are zoned, much easier than with forced air systems. Each room in a house or building can easily be separated in a radiant floor system. This allows for different temperature settings and the ability to turn down spaces that are not commonly occupied. When you can more easily control your system and send the heat to where you need it, you can save more on your operating costs.