In a world where energy efficiency and comfort are increasingly important, scientists are constantly on the lookout for better ways to heat our homes. A team of researchers, including Hongli Sun, Yifan Wu, and Borong Lin, recently led a study that introduced a new type of heating system that could transform our understanding of indoor comfort. Their findings focus on a novel heating method that combines radiation and convection, and it could save energy while keeping indoor environments more comfortable.
Published in Engineering in 2024, the research delves into the potential benefits of this new system for individuals residing in homes and small buildings, particularly in regions with less severe heating requirements.
The problem with traditional heating
If you’ve ever experienced the slow, uneven warmth of a radiant floor heater or the quick but sometimes drafty warmth from a fan coil system, you know that neither is perfect. Radiant floor heating works by gently warming surfaces, like the floor, and then transferring that warmth to the air. This provides a comfortable, even heat over time, but it can take a while to warm up a room. On the other hand, fan coil systems use forced air to quickly heat a room, but they can create uncomfortable drafts and often don’t distribute heat as evenly as we’d like.
The research team claims that these traditional systems are not suitable for “intermittent heating,” an energy-saving technique that only heats a space when necessary.
“Conventional radiant heating and convective systems each have their strengths, but neither can provide fast, comfortable heating during intermittent use,” said Hongli Sun, the leading researcher of the study. In today’s world, where energy conservation is key, finding a system that can work quickly and efficiently is more important than ever.
A new hybrid solution
So, what’s the solution? The team has come up with a hybrid system that combines the best features of both radiant and convective heating. The idea is to use convection (forced air) to quickly heat up a room and then switch to radiation (like a heated floor or panel) to maintain that warmth comfortably.
Here’s how it works in simple terms: Imagine walking into a chilly room and turning on this new hybrid system. The convection kicks in first, using a fan to push warm air into the space. This gets the room up to a comfortable temperature in just 20 to 40 minutes, which is a big improvement over the hours it might take with traditional radiant heat. Then, once the room is warm, the system switches to radiation. Instead of continuing to blow air, which can be noisy and drafty, it uses radiant panels or floors to maintain a steady, comfortable warmth.
As Borong Lin explained, “We wanted to create a system that could quickly bring a room to a comfortable temperature but also maintain that comfort without the drafts and temperature fluctuations that come with forced-air systems.”
Why this matters?
You might be wondering: Why is this such a big deal? For one, it’s about comfort. Nobody wants to wait hours for a room to warm up, and nobody enjoys sitting in the path of a hot, dry air current from a traditional fan coil system. This new system solves both of those problems by blending rapid heating with the gentle, even warmth of radiant systems.
But it’s not just about comfort. Energy efficiency is a major concern, too. Homes and buildings account for nearly 30% of global energy consumption, and heating is one of the biggest contributors. Intermittent heating, where you only heat a room when needed, is an important strategy for saving energy, especially in homes that don’t need constant heat.
This new system, which combines radiant and convective heat, can deliver quick warmth without wasting energy by overheating spaces. Once the room is warm, the radiation mode takes over, using less energy to maintain a comfortable temperature. According to the study, the system can stabilize indoor temperatures between 18°C and 22°C, considered perfect for most homes. “The goal was to maximize comfort while minimizing energy use, especially in regions with low heating demand,” the researchers noted.
Real-World Impact
This system has huge potential for homes, offices, and even larger buildings. One of the biggest advantages is its ability to adjust heating based on different needs. For example, if you’re having guests over and need to heat your living room quickly, the system can kick into high gear with convective heating. But if you’re just sitting and relaxing, the radiant mode can keep you comfortable without any sudden drafts or temperature spikes.
As the researchers pointed out in the study, “The flexibility of the system allows it to adapt to varying indoor conditions, making it an ideal choice for homes in climates that experience moderate to cold winters.” It’s also a perfect fit for offices and other spaces where intermittent heating could lead to substantial energy savings.
While this new system has already shown outstanding promise, the research team is looking for ways to improve it even further. Future studies will focus on making the system even more efficient by improving the materials used in the radiant panels and enhancing the heat exchange process. For instance, they are exploring ways to reduce internal thermal resistance, which would allow for even faster heating.
The potential for this hybrid system to revolutionize indoor heating is clear. With homes and buildings facing increasing pressure to become more energy-efficient, a heating system that combines comfort, speed, and efficiency could be just what we need.
As Hongli Sun puts it, “Our work shows that it’s possible to create systems that provide both comfort and energy efficiency, making it a win-win for homeowners and the environment.”
For more, refer to the citation: Sun, H., Wu, Y., Lin, B., Duan, M., Yang, Z., Zhao, H., Wei, Z., Yu, S., Li, S., & Song, J. (2024). Indoor Thermal Environment Improvement Based on Switchable Radiation/Convection-Combined Intermittent Heating: Comparison between Conventional Terminals and Integrated Novel Terminal. Engineering. https://doi.org/10.1016/j.eng.2024.08.020
