Before installing the heating system, it is necessary to: install windows and window sills; put plaster on the walls in the places where the radiators will be, under each window; prepare the boiler room, i. e. plaster the walls or put ceramic tiles on them or other materials; prepare the floors, but do not make finished floors or final decorations — that’s done later.
Installing the heating system in the rooms starts with the installation of the radiators on the walls. For this, the radiators are leaned against the wall and we mark the places where they will be installed, checking that they are horizontal, and we install the brackets for attaching the heating devices. Then hang the radiators on to the brackets. The original packaging from the manufacturer should not be removed from the radiators while they are being installed — install the radiators still covered with it. The packaging can be taken off after all wet and dirty work has been finished. This will protect the radiators from scratches and dirt.
It should be noted that in the instructions for installing radiators, it is always recommended to install them absolutely horizontally. However if you install them with an almost unnoticeable slope from the supply pipes, then it will not hurt the appearance, but it will contribute to the remove of air locks from the radiators into the pipeline. However this applies only to heating systems with low operating pressure, in which the «continuous flow» or counter-flow removal of air is possible, or in pumped heating systems in which air and warmth carrier move in the same direction. In systems with pumped circulation and counter motion of air and warmth carrier, an air lock can not move to join the warmth carrier and will be pushed back to the radiator. In this case, the radiators should be installed absolutely horizontally and they should be provided with automatic air purgers or Mayevsky valves.
Pipelines for connecting radiators are mounted in several ways (see Figures 85–87). For three-way systems with vertical pipelines, the pipes should be installed outside the walls, as a rule, putting them along the walls, around the perimeter of the house, but it is possible to use a hidden setting by hiding the pipes in grooves made in the walls. For one-piped collector settings, the method of hiding the pipes around the perimeter of the house or under the floors is more often used. Connecting to the radiators is done by lifting the pipes from the floor, or else the pipes from the floor are put into grooves in the walls and then from the walls they go out to join the radiators. Two-piped collector settings are made either by the beam method, attaching each radiator to the collectors, or the pipes are put along the perimeter of the walls and the radiators are attached to them in series. The pipes in the floor later have concrete poured onto them; if the floor is constructed of wood on top of beams, then the pipes go in the gaps between the beams and through them under the floor boards. In all cases of hidden installation of pipes, they are put inside a protective insulated pipe. The pipes mounted this way will be protected from damage and they will have room for thermal expansion.
Installation of collector heating systems should begin after the piping of the boiler and installation of floor collectors that are mounted in a box on brackets. The collectors should be easily accessible for maintenance and inspection. It is recommended that not more than ten radiators should be connected to one collector. In accordance with basic requirements for installation of heating systems, the supply collector should be mounted above the return collector. The installation of the pipes starts from the supply collector. If the heating pipes are in a screed of the floor, you need to install an air remover on each radiator. To prevent airing in the collector itself, it is necessary to install an air remover on it as well. Installation of a vertical pipe heating system begins with mounting and fixing the vertical lines of supply and return with T-shaped connectors or elbows already installed on them for connecting outlets to the radiators.
The ends of the pipes which are not yet connected to the system, in order to avoid clogging with dirt, must be closed with plugs or wrapped in rags. The supply and return pipelines and also the outlets to the radiators must be marked with tags, stickers, or colored ribbons. This will prevent the mixing of supply and return pipelines and greatly facilitate the installation and testing of the system.
Installation of collector heating systems with metal-plastic pipes is done only by using one-piece crimp connections on press fittings and fittings with a slip-sleeve as only these connections can be hidden inside walls and in the floor screed. Pipe settings of polypropylene and copper pipes must be connected by soldering or welding. After the system has been installed, and subjected to hydraulic tests, it is recommended that before putting concrete on the floor, all the fittings and connections be protected from the concrete. For this purpose, the connections need to be wrapped in film, foil, etc. , which will protect the fittings from surface damage.
Connections of radiators to the pipes is as diverse as the laying of the pipelines. Radiators can be simply connected to the pipes on elbows and straight «Americans» (see Figure 88). An «American» is a detachable fitting; it can be unscrewed and one of its halfs can be screwed on the short pipe thread and the other half is screwed to the plumbing fixture. Then both of the halfs are screwed together by a union nut which is put on the fitting. Thus the radiator can be removed if necessary without disassembling the pipeline.
Ball valves are installed before the «American» connectors so that the radiators can be removed without having to drain the warmth carrier from the heating system, for example, for cleaning them (set Figure 89).
If you want to install a heating system with room air regulation, then while connecting the radiators to the pipes, thermostatic valves with manual management or thermostatic heads with bellows or servodrives are usually installed (see Figure 90 and Figure 34). As a rule, the installation of valves with thermostats on radiators is sufficient to make the heating system regulated without using three-way or four-way mixers on the heating contours. However, in this case, installation of relief valves is necessary (see Figure 86); these release pressure from the heating contour if suddenly all thermostatic valves close the motion of the warmth carrier in the radiators.
Thermostatic valves, depending on the air temperature in the room, close the hole through which the warmth carrier passes, thereby regulating its supply; but they do not operate simultaneously. When the air temperature in the room reaches the preset value on the thermostat, the bellows starts to work and closes the saddle of the valve, and this stops the motion of the warmth carrier. The thermostats of some companies are activated instantly; others do it more gradually. Besides, radiators which are closer to the generator of the warmth are hotter and the further radiators are less hot. There is an imbalance in the heating system (see Figure 91). Therefore, a connection to valves with thermostats is a necessary condition for regulating heating systems, but it is not enough. On the return pipeline from the radiators, balancing valves must be installed, which are in general the usual saddle valve with a tapered rod (see Figure 92). Opening this valve by one, two, or several revolutions regulates the supply of the warmth carrier through the radiators. Regulation is done, with the thermostatic valve fully opened, according to the special charts provided by the manufacturers of the balancing valves, or valves with a hole for a portable meter are used. Shut-off valves are not installed on radiators in this case. The radiator can be removed by closing the balancing and thermostatic valves.
However, it should be noted that while thermostatic valves and balancing valves of this type do not work badly in individual heating systems, they are practically useless in central heating. Our very long and worn out heating mains are mostly made from steel pipes; rust comes off inside them and instantly fills completely the saddles of regulative valves. If you decide to install thermostatic valves in your apartment, then it is necessary to install mud filters before them and you must clean them periodically.
In heating systems with vertical one-piped setting, radiator connections are done through three-way valves with thermostatic head or through a conventional valve with a thermostat and shut-off valve (see Figure 93).