Retrofitting the Comfort of Ceiling Heating in an Old Building on a Room-by-Room Basis

Get the benefits of radiant heating as a retrofit

A ceiling heating system with RTL control makes it possible to utilise radiant heat in older buildings. Radiant heat from the ceiling most closely resembles natural sunlight and significantly reduces the stirring up of air and dust. A pleasant, even temperature and a healthy indoor climate enhance living comfort. An increasing number of hospitals and other medical facilities are also opting to retrofit ceiling heating systems for health reasons.

The thermodynamic principle that ‘warm air rises – cold air sinks’ plays a minor role in ceiling heating. 90 per cent of the heat transfer to the room is achieved via radiant heat. The proportion of radiant heat is significantly higher with ceiling-mounted radiant heating than with wall or underfloor heating. For this reason, it is also referred to as radiant ceiling heating.

In view of ever-higher record temperatures during the summer months, the function of a cooling ceiling is also becoming crucial in homes. Provided there is sufficient cooling water – for example, by operating a reversible heat pump – the ceiling heating system becomes a climate-control ceiling that ensures pleasant room temperatures even in summer.

Very even temperatures, energy efficiency and the option to use it as a heating and cooling ceiling make ceiling heating the all-rounder among surface heating systems. The FLEXIRO kits make retrofitting possible room by room in older buildings. Design flexibility and energy efficiency are also compelling reasons for retrofitting. Here are the benefits of a heating and cooling ceiling in detail:

Benefit Thermal comfort

A water-based ceiling heating system with pipes that are as thin as possible implements the principle of surface heating almost perfectly. That is why FLEXIRO uses 10 mm polyethylene or copper pipes, which allow for close installation spacing and distribute the heat particularly evenly across the ceiling surface into the room. As the ceiling is usually unobstructed, a ceiling heating system can be easily retrofitted, allowing heat to be transferred to the room without being impeded by fixtures or objects. In this way, a remarkable level of thermal comfort can be achieved in older buildings even at low flow temperatures. Due to the high proportion of radiant heat – which is also reflected by the walls and floor – a room temperature of 20 °C generated via the ceiling surface is perceived as being just as warm as 22 °C produced by radiators.

The following diagram shows temperature profiles according to room height for various heating systems, compared with the body’s thermal comfort zones. Ceiling heating comes closest to the ideal form of room heating. It creates a uniform temperature distribution, ensuring a high level of thermal comfort throughout the entire room height.

The graph also shows that, with ceiling heating, the floor temperature is slightly above the room temperature, as the floor is also heated through absorption and reflection. There is no need to worry about cold feet.

Benefit Healthiness

As the surfaces are only slightly warmed and there is an even temperature distribution throughout the room, there is hardly any air turbulence. This means that fewer allergens circulate in the air. People with house dust allergies, in particular, appreciate this benefit of ceiling heating. Mould growth is also actively prevented, as thermal bridges at corners or window reveals and temperature differences within the room – which are the main causes – are prevented from the outset by the even heating of the large ceiling areas.

Benefit Design freedom

Another advantage of water-based ceiling heating is that it is concealed from view. The interior design, window layout and furnishings are not obstructed by permanently installed radiators. Climate ceilings regulate the room temperature discreetly and silently. The space saved can be put to good use. This opens up entirely new possibilities, particularly when it comes to heating sloping ceilings.

Benefit Energy efficiency

Ceiling heating reduces heating costs in older buildings. Low flow temperatures result in significant energy and cost savings. However, installing the heat exchanger pipes close to the surface of the ceiling ensures a rapid response when heating. Heating and cooling ceilings operate particularly efficiently with heat pumps and renewable energy sources such as solar or geothermal energy, which work with small temperature differences. 

Benefit Climate ceiling

The FLEXIRO system can be used for cooling in the summer without the need for any modifications. The only requirement is a sufficient source of cooling water. Against a backdrop of rising peak and average temperatures, climate control is becoming increasingly important in residential settings too. A heating and cooling ceiling ensures pleasant temperatures even during the summer months. Compared to air conditioning, the climate ceiling achieves this using significantly less energy and with a smaller environmental footprint.