The methods of installing pipes to heating devices in a radiator heating system can be quite different: low, high, diagonal, side, with internal circulation. The most common and preferred is the low type where the advantages of metal-polymer (metal-plastic and reinforced polypropelene) pipelines can be realized, and in this type the pipes are hidden under the floor or behind the molding.
In recent times, when choosing a scheme of heating system for a suburban house, preference is given to having a «collector» setting on each floor, and also combining this with one-piped and two-piped system. The pipes are hidden under the floor and collectors are installed in the centre of the house in a niche in the wall, or placed in a box (see Figure 23). The pipes go from the collectors to each radiator. In practice, it is necessary to create a forced circulation in the system and this is achieved by installing one or several circulating pumps. This allows the difference in temperatures in the input and output of the net of the system to be decreased, and therefore to increase the effectiveness and regulation of the heat and also to avoid additional waste of materials, to simplify the system, and to make it more compact. Each output of the collector can be equipped with a ball valve which allows, in some schemes, any radiator of the system to be turned off while not disturbing the work of the other heating devices. Moreover each heating contour which is situated after a collector is in essence an independent system, which can be equipped with its own circulational pump, valves, and automatic devices.
Collector heating schemes most often are used in two-piped and one-piped horizontal settings and nowadays they have almost replaced T-shaped horizontal settings.
Supply and return collectors are placed on the main vertical pipeline of each floor. From the collectors, supply and return pipelines go under the floor or inside the wall to each radiator on the floor. One should try to make each ring have approximately the same length. If this is not possible, then each warmth ring can be equipped with its own pump and its own automatic regulator of warmth carrier temperature, and therefore the regulation of temperature of one warmth ring would not affect the others. Since the heated pipes are located under the floor, it is necessary to install air valves on each radiator (see Figure 24) or an automatic air remover can be placed on the collector or air removers can be installed both on the radiators and on the collector.
A disadvantage of this system is that the pipelines have long lengths.
If the calculations for the heating system are well done, then it is possible to do without radiators and in this case the closed warmth rings are hidden under the floor (see Figure 25). This heating system is called Radiant Floor Heating. Most often this is an extra system, but with good calculations it can fully replace the radiator heating system.
A radiant heating system provides comfortable conditions. The flow of warmth is spread over all the area of the floors and temperature decreases evenly with the height of the room. With radiator heating, the air temperature, conversely, increases with the height of the room, and this causes a strong convection of air which takes dust from the surface of the floor and raises it up. In a radiant floor heating system, the natural motion of air is limited and there will be less dust in the house.
