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Comfort with commercial radiant heating products

Aug. 6, 2014
We need to design these systems around the occupants of the building, and not the building’s needs. Simply having a thermostat set for the typical 68°F to 72°F comfort zone is not enough to guarantee a good comfort experience. 

The use of alternative radiant heat-emitting surfaces for commercial buildings has been an industry norm for many years. Radiant ceilings are the most common application of these devices. In a properly designed and installed system, a radiant heating ceiling system can make all of the difference in the world as it pertains to occupant comfort. Many times, these retrofit heating panels are placed to counter poor system designs and/or controls.

For a typical given scenario, where the thermostat is usually located in the core of the building and doesn’t see the heat losses occurring in an exterior room – causing major discomfort in the outlying rooms, especially where there is a significant amount of glazing, which is typical of commercial office buildings – these panels can be the difference between an acceptable level of comfort or an unacceptable one.

They come in hydronic versions as well as electric versions. They are typically the same size as drop-in ceiling tiles, 2-ft. x 4-ft., and come in various colors and textures.

When properly designed and installed, they can mean a significant decrease in the volume of air required for maintaining a healthy working environment. This comes from the fact that the air movement required at that point is only the air movement necessary to comply with air changes per hour based on use and occupancy.

This significant reduction in fan power can justify the expenditures and may result in energy reductions of between 30% and 50%, depending upon the application. And as previously noted, we will now be affecting the mean radiant temperature (MRT) within a given space, and as we all know by now, a well-controlled MRT is the primary factor in determining a high degree of human comfort.

As my good friend Robert Bean, and his very knowledgeable ASHRAE associates, have been saying, we need to design these systems around the occupants of the building, and not the building’s needs. Simply having a thermostat set for the typical 68°F to 72°F comfort zone is not enough to guarantee a good comfort experience.

How many times have we, as technicians, received complaints from building operators that the people are not comfortable, even though the thermostats say the building is satisfied? And we as technicians keep doing the same thing, and getting the same results. We walk in, check the thermostat, and confirm its accuracy and the fact that the air temperature is at set point. There is really not a lot more that we as technicians can do at that point.

It is on and it is working to our expectations. But the people within this space are not comfortable, even at 70°F to 72°F air temperatures. Old habits are extremely hard to break. However, if we, as energy and comfort technicians, were to look at more than just the thermostat and air temperature through an infrared imaging set of eyes, we would see that the occupants are being exposed to lower than acceptable mean radiant temperatures, and this usually results in the “Cold 70” nuisance call that I previously described.

We, as an industry, have long recognized the benefits of hydronic and electric radiant heating. But when it comes to service calls and trouble shooting, we forget everything we know and address it from our conventional air temperature sensing methodology, which doesn’t always correctly address the human occupant needs. We need to continue working on that part of the equation. Not just as designers and installers of comfort systems, but also from the educational standpoint.

We need to educate the building owners, architects, energy modelers and even our own employees. Radiant heating and radiant cooling systems are the most comfortable, most efficient systems made. They are perfectly compatible with every water heating and or cooling methodology known to mankind.

Awhile back, the RPA announced the formation of a new committee dedicated to maintaining its current market share of hydronics. This is a serious group of dedicated hydronic and electric equipment manufacturers. They have launched an advertising campaign focused on the people who make the decisions about how all of these commercial buildings are going to be maintained comfort wise.

If you have not yet had the opportunity to check out their efforts, please do so in the near future, and please consider becoming involved with this group. Check out the progress of their newly dedicated website at If you are a manufacturer and are interested in joining this very well organized group, please contact me at [email protected]. I will make sure your company receives an invitation to join, along with all of the information this group of manufacturers has put together.

If you have not joined or re-joined the RPA, by all means please do so by visiting the RPA website at and click on the Join button. Membership comes with many benefits, the most important being support of our industrywide efforts to increase the awareness and use of hydronic- and electric-based radiant comfort delivery systems. Thank you for your continuing support.

Tune in next month as we continue our efforts to educate and enlighten people about these wonderful, efficient comfort systems.

All Mark Eatherton material on this website is protected by Copyright 2014. Any reuse of this material (print or electronic) must first have the expressed written permission of Mark Eatherton and CONTRACTOR Magazine. Please contact via email at: [email protected].

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