FUNCTIONAL PRINCIPLES AND FEATURES OF SURFACE HEATING AND COOLING SYSTEMS WITH CLINA CAPILLARY TUBE MATS
Clina Capillary Tube Mats are installed directly under the surface of one or several room enclosing surfaces – these can be the ceiling, the walls or the floor.
For heating or cooling spaces, warm or cold water flows through the very thin capillary tubes having outer diameters of 3.4 or 4.3 mm. The surfaces equipped with Clina mats are maintained at an even surface temperature. They ensure a quick dissipation of the cooling load or a quick supply of the heat requirement, mainly through radiation and partly through convection.
Due to the large exchange surfaces, considerable amounts of energy can be transferred draught-free and silent even at minor temperature differences between the active room surfaces and the room air.
PRINCIPLE OF THERMAL RADIATION
COOL SPACES WITH CLINA CAPILLARY TUBE MATS
For COOLING purposes, Clina Capillary Tube Mats are preferentially installed either in or on the ceiling; in this case the surface temperature of the ceiling is, depending on the supply temperature, approx. 19 °C at only 2 to 3 K spreading between supply and return (supply temperature = usually 16 °C; return temperature = 18 °C or 19 °C). Depending on the type of ceiling or the way the capillary tube mats are installed, cooling capacities of up to 100 W/m² (Δ=10 K) can be achieved for closed radiant cooling ceilings.
Surface cooling systems bear the risk of dew point exceedance and of condensation on the cold surface. This risk can be safely ruled out! Therefore each control zone is equipped with one or several dew point sensors. To avoid condensation on the cooling surface, in case of a dew point risk the flow through the capillary tube mats is stopped by closing the control valve. Switching off the individual zones can be counteracted by using an enthalpy-based supply temperature control.
In large and intensively used office buildings cooling ceilings are often combined with a supporting ventilation system, so that dew point exceedance happens very rarely. This is necessary as a rule in order to provide all users with the required fresh air as well as to remove the bad air. The relative humidity is controlled by ventilation and maintained at a comfortable and dew point non-critical range for the users of approx. 50% relative humidity.
Due to the fact that the dissipation of the cooling loads, with this type of system combination, is performed by the cooling ceiling, the air change rate can be reduced to the hygienic minimum necessary (approx. two to three air changes per hour) and the size of the ventilation system can be considerably reduced.
WARM SPACES WITH CLINA CAPILLARY TUBE MATS
For HEATING purposes, warm water with a temperature between 28 °C and 35 °C flows through the Clina capillary tube system. In this case, the surface temperature of the ceilings is at approx. 27-30 °C. That way, even during the heating phase, the radiant energy from the user is transferred to the ceiling.
Studies have shown that, when the entire ceiling surface is activated, up to an output of approx. 60-70 W/m², depending on the symmetry in radiation, no losses of comfort are expected when heating by the ceiling.
Higher outputs can be achieved via the floor surface (100 W/m² according to DIN) and the wall surface (130 W/m²), with full comfort.
Due to their considerably larger surface, Clina capillary tube mats are much more efficient than conventional systems. This is evident from the fact that they require substantially lower supply temperatures to obtain the same heating capacity. Therefore, Clina capillary tube technology is the ideal heat transfer system for heat pumps, whose coefficient of performance increases accordingly. Furthermore, Clina capillary tube mats allow the realization of extraordinary low installation heights. For floors e.g. it is possible to apply the Clina capillary tube mats not only in the screed, but also in the thin-layer process directly under the floor covering.
In general, Clina Heating and Cooling Systems are considerably more responsive than conventional systems due to the position and geometry of the capillary tubes.
Ceiling | Cooling ceiling & ceiling heating
A significant area of application for Clina capillary tube mats are thermally activated ceilings, which are often used in large office and administration buildings.
Capillary tube systems have become established throughout Europe, particularly in the segment of cooling ceilings, since the first projects at the end of the 1980s, compared with conventional air conditioning systems. The reasons for this are manifold:
- no negative effects on the health of the users (draughtfree and noiseless) with considerably higher comfort
(radiant cooling system)
- significantly lower energy consumption = lower operating costs
- no maintenance required, nevertheless longer system life
- "invisible technology" with drastically reduced space requirements for installation
- environmentally friendly in production, operation and disposal (recyclable PP)
Compared to cooling elements made of copper pipes pressed into heat conducting profiles, plastic capillary tube mats differ mainly insofar that a suspended ceiling construction made of metal or gypsum board is not necessarily required. Due to the small outer diameter of the capillary tubes and their flexibility, capillary tube mats can also be plastered directly onto the bare concrete ceiling - even on curved surfaces!
If the ceiling is also used for heating, a conventional heating system is replaced. This means that the Clina ceiling system can not only be used for cooling, but also for very convenient and energy-efficient heating. Due to low supply temperatures, the ceiling heating system ensures an extraordinary sense of well-being, similar to the principle of solar radiation on the earth's surface (radiant heating system).
GYPSUM BOARD CEILINGS
Wall | Wall heating & Wall cooling
Clina capillary tube mats can be integrated into walls of various designs and used as wall heating and wall cooling. The mats are very flexible and can be adapted to all spatial conditions, e.g. slopes or vaults. Thanks to its flexibility and very low installation height, this Clina system solution is ideal for building renovation.
The radiant heat of Clina wall heating is particularly comfortable for the user, as it is reminding one of the pleasantly warm rays of the sun. A further plus point is the possibility of using Clina wall cooling in summer to provide highly convenient cooling, draught-free and silent cooling. This means that, if required, space cooling can also be switched on at night without any problems. In many cases, the necessary cooling energy can be obtained from the environment almost free of charge using alternative systems - for example via capillary tube mat ground collectors in the ground.
The capillary tubes, which are completely enclosed by the plaster, result in heat conduction over a large area. This, and the position of the capillary tube mats close to the surface, results in a high heat output or cooling output at low system temperatures. The low system temperatures and the short heating and cooling times save energy costs and preserve the environment.
Floor | Underfloor heating
Underfloor heating systems with Clina capillary tube mats can be used for temperature control in all buildings. The water-carrying capillary tube mats are either integrated into an existing screed or laid directly on an existing floor as a thin-layer underfloor heating system and enable gentle temperature control of floor surfaces.
Due to the homogeneous heat distribution, a low system temperature can be used. This has a positive effect on the feeling of well-being and reduces heating energy consumption, which in turn saves money and protects the environment. The perceived temperature is about 2-3 °C higher than the actual room temperature.
Thanks to the small spacing of the capillary tubes of 20 mm, the floor is heated homogeneously. This, and the position of the capillary tube mats close to the surface, results in a high heat output at low system temperatures. This leads to extremely short heating-up times. Already a few minutes after switching on the heating, the heat is perceptible on the entire floor. Even with the classic installation of underfloor heating in the screed, the capillary tube system only requires approx. ¼ of the heating-up times compared to conventional underfloor heating systems.
Room elements | Heating, cooling & dehumidifying
The GRAVIMAT is a convector for heating, cooling and dehumidifying. Especially in the warmer countries of the world it is highly appreciated for its simple construction and convincing function. Even at highest temperatures with high humidity, the GRAVIMAT cools down the room air reliably to pleasant temperatures and this energy-efficiently and without restrictions. The consequences of climate change lead to an increased demand even in more temperate climate zones.