Chris Stammers of BEAMA’s Underfloor Heating Group explains how hydronic underfloor heating creates thermal comfort through even heat distribution and efficient heat transfer.
Creating a sense of thermal comfort in a building is essential for the wellbeing of occupants. However, to achieve optimal comfort, it’s key to maintain indoor environments that minimise the body’s need to regulate its temperature actively, thereby ensuring people occupying the space feel neither too hot nor too cold. Many factors influence whether someone experiences thermal comfort. While it’s highly subjective and varies from person to person based on several factors, creating a comfortably warm indoor environment is universally beneficial.
Even heat distribution
Ensuring an even distribution of heat throughout a space is imperative. The only heating system which can heat all surfaces in the room evenly is radiant heating, specifically hydronic (water-based) underfloor heating. The series of continuous loops fitted under the floor – either within the screed or within specialist panels – creates a large radiant surface that heats a room from the floor upwards. The radiant heat travels upward from the floor to warm the objects and people in the room to create an immediate feeling of comfort rather than only heating the surrounding air.
When there are parts of a room which are much cooler than others, condensation may gather when the warm, moist air comes into contact with cooler surfaces, such as walls or windows. This moisture then provides an ideal environment for mould growth and, therefore, poor air quality due to the mould spores. Pollutants such as dust and allergens can also get ‘trapped’ in poorly heated areas of a property. While ventilation plays an essential part in good indoor air quality, from energy conservation and security aspects, having windows open during the cooler months isn’t always an option.
As the floor becomes a large heat emitter, it’s evenly distributed across the surface, which helps maintain a comfortable ambient temperature throughout the space, and eliminates hot and cold spots in a room. The nature of underfloor heating also means the heat felt by the occupants is gentle and comfortable rather than overwhelming.
In addition, thanks to the stable and consistent temperatures created by underfloor heating, it maintains and balances humidity levels, further improving indoor air quality and delivering comfortable living environments.
Reduced air movement
Radiant heat delivered by underfloor systems directly heats objects and surfaces rather than the air, so it doesn’t create convection currents to create thermal comfort. Instead, radiant heat warms the very fabric of a room. Minimising air movement is important to support a sense of wellbeing within the indoor environment, particularly for those who suffer from respiratory problems.
Many aspects of a property and individual rooms can improve or deteriorate indoor air quality. One main culprit is the movement of problematic particles, such as dust and allergens. These particles can’t be avoided easily, but when they become airborne, they cause more issues, especially for those with respiratory problems. Underfloor heating prevents these particles from circulating, thus improving indoor air quality.
Plus, because underfloor systems are entirely hidden within the floor, there aren’t any hard-to-reach components, such as coils or panels, where particles can gather and be dispensed into the space when the system is active. Regarding aesthetics, they are completely hidden within the floor, allowing for complete interior layout freedom while seamlessly integrating with almost every flooring material, contributing to a comfortable living space overall. So, in the case of underfloor heating, the term efficiency applies to both system performance and space efficiency.
Flexible zoning options
Underfloor heating systems must now have zoning capabilities to comply with the Part L low-temperature update to the Building Regulations. Standard thermostats meet the regulations but commonly only offer a single temperature setting for a whole property, missing out on the energy-saving benefits of zoning, which many smart thermostats are designed to work with.
Zoning allows the end user to create distinct temperatures for each space, each with personalised settings that can be altered and monitored from the thermostat or smartphone. This allows the end user to create the right level of comfort in each space—for example, warmer in the living area and cooler in the kitchen, where heat is already produced from cooking activities. It also ensures that vacant zones aren’t heated unnecessarily, helping to save significant energy, especially for larger properties.
Adaptive Start functionality is another smart feature in more advanced devices. It can work with the local weather forecast to activate the heating at just the right time based on external weather conditions. This is another excellent example of how thermal comfort can be delivered by specifying some of the innovative energy-saving features of smart thermostats.
Chris Stammers is portfolio manager for BEAMA’s Underfloor Heating Group, the UK’s national trade association for underfloor heating