In the previous pages of the website, mainly heating systems based on hydrocollectors «HydroLogo» from the company Hydromontage were discussed, giving the most complete picture reflecting the conception of primary-secondary rings. However in the Russian construction market, there are other manufacturers of boiler modules of quick installation; the most interesting developments are presented by the German company «Meibes» and the Italian company «Lovato». Both companies offer their groups of hydrocollectors and prefabricated pump-mixing groups.
Hydrocollectors of these companies are somewhat different from those of HydroLogo and therefore we will discuss them separately.
The HydroLogo hydrocollectors are classical heating system «combs», fully reflecting the idea of a primary-secondary scheme, and almost exactly following it, but hydrocollectors from «Meibes» and «Lovato» are made somewhat differently. In the classical «HydroLogo» hydrocollectors, the hot water in the supply and the cooled water in the return are mixed together and can be divided only using a waved or flat non-hermetic internal wall (see Figure 52), but in the «Meibes» and «Lovato» hydrocollectors, the heating of the return water is done by transferring warmth through a thin hermetic internal wall. Moreover in the hydrocollectors of these companies, but mostly Lovato, a double usage of collectors is possible (see Figure 69). A hole is made in the internal wall which is closed by a threaded rod by the twisting or untwisting of which the hydrocollector can be converted into a «comb», similar to the HydroLogo hydrocollectors, or into a usual coaxial collector. By incomplete tightening of the rod, it is possible to regulate the mixing of supply and return. It is for this reason we put these warmth schemes in this chapter because the assembled heating systems based on «Meibes» and «Lovato» hydrocollectors can work both on classical primary-secondary and combined heating schemes, where the consumers of warmth «sit» on the usual parallel collectors.
After the boiler piping all the hydrocollectors must be heat insulated. The hydrocollectors which are available come with insulated cases made of polystyrene foam.
Together with hydrocollectors, company manufacturers of boiler equipment sell pump-mixing groups. These modules are ready-made units which consist of three-way mixers, circulational pumps, bypasses with integrated bypass valves, thermometers and so on (see Figure 70). When installing the boiler pipes, there is no need to purchase each of the mechanisms separately; it is enough to buy a ready-made pump-mixing module and attach it to the hydrocollector. Each heating contour has its own module, in which there are selected mixers, valves and circulational pumps. The modules originally are made for manual regulation of the warmth carrier temperature, but can be easily converted to an automatic regime mode by installation of sensors, servodrives and thermostatic heads. However also manual regulation is not too difficult. The modules are equipped with thermometers and just by turning the handles of the three-way mixers and two-way valves, you can set the desired temperature.
The setting of a heating system on hydrocollectors and pump-mixing groups will look very simple (see Figure 71). The following modules are attached to the hydrocollector: for low temperature heating systems with three- and four-way mixers; for high temperature, with two-way (ball) valves. We already know from the previous chapters how all this works. Two modules whose schemes we have not yet discussed, as they are somewhat different, are: a separation unit and a return water heating unit.
The separation module is equipped with a miniature heat exchanger which fully separates the heating contour and the boiler contour. The warmth carrier from the boiler flows into the heat exchanger and heats the plates or a coil of the heating contour in it; i.e. the warmth carrier from the boiler contour misses the consumer contour and only gives off heat. Such separation of the heating system into two independent contours is done if there are high demands on the warmth carrier in the heating contours. It remains clean and circulates only in its own contour. Usually such systems are provided for contours of «warm floors» or for air (convector) heating in which small-diameter pipes are used and any accumulation of salts in them is unacceptable. The separation modules are equipped with outlets for attaching their own small expansion tank and replenishment of warmth carrier.
The module of heating return water regulates the temperature of the return, not allowing it to cool to condensation temperature in the boiler, thus benefitting the work of the boiler. The module is equipped with a thermostat and a mixer which tell the boiler to start when the temperature of the return falls below an acceptable level. The module can be connected to a separate boiler or to a collector.
For wall-mounted boilers, Meibis has its own module, «Thermix», which also can quite easily be attached to the boiler outlets (see Figure 72).
Installation schemes of boiler piping with hydrocollectors from the Lovato company are practically the same as the piping from Meibes, with one difference, that the Lovato hydrocollector can be used both as a mixer (hydraulic «arrow») and as the usual paired collector. For example, a hydrobalancer and hydrocollector can be included in a boiler piping scheme (see Figure 73). In low power boiler rooms, it is possible not to install a hydrobalancer, but just unscrew the rod in the hydrocollector and convert it into a hydrocollector working on the primary-secondary ring scheme.
For clarity, we recall that when connecting a wall-mounted boiler with a usual T-manner with an integrated circulational pump and expansion tank, the setting itself from the boiler is simplified, but difficulties with balancing of the heating rings appear.