DESIGN EXPERIENCE
With the slope-less and floor systems, where a deviation from the flatness of the foundation may occur, it is recommended to overrate the pump output (in terms of both flow and pressure) by 50 up to 100% in comparison to the calculation. In case of REVEL-PEX system projects it is entirely useless to draw vertical connection of individual bodies, since a scheme of distributor connection and ground-plan layout of distributions suffices. Similarly to this, isometrics of consumption points does not have to be drawn for water distributions. This spares work on the drawing documentation. Distribution system designs may be exactly based on experience (maintain the speeds in the range from 0.5 up to 1 m/s), or can be worked out using the XproCAD REVEL program (update version, including supportive CAD and brief download instructions on
www.revel-pex.com/software). The system can be used in different connections. However we recommend the alternative with distributors located in the centre of the space and connection of individual heating circuits, while each of them includes several bodies in “Tichelman” connection type, as the most economical, safest in operation and best in terms of thermal comfort. Distribution pipes are led on the perimeter of outer walls to the maximum extent possible and, unlike internal distributions, without insulating or protective covers. Possible indicative output of this two-pipe line is 50W/m. In case of family houses and buildings of up to 300 m2 floor area of each individual floor connection without distributors proved well, where branch line of 23 dimension is led from the ascending pipe and using a T-piece it is divided into two circuits in the floor, which connect individual bodies using Tichelman connection type. Here, however, the diameter change is expected. The above mentioned boiler connectors in case of multi-level systems are used similarly. For surface distributions metal-plastic pipe placed in conduit clamps is used. Due to the lower roughness of pipe walls the REVEL pipes show about one-grade better transmission properties than steel.
Recommended maximum transmitted output in individual pipe dimensions and temperature gradient of 20 °C is as follows: dimension 16–7 kW, dimension 20–12 kW, dimension 23–25 kW, dimension 32–40 kW and dimension 50–200 kW. When designing the connections and distributors of the floor heating it is necessary to take increased through-flows into account with respect to lower temperature gradient. On the contrary, the connection in case of mixing distributors may be subtle due to high temperature gradient. The above mentioned information is only indicative, since everything always depends on particular conditions. The graph for the mean temperature of 70 °C illustrates the relationship between pressure losses and flow rate in individual pipe dimensions. Shaped pieces and distributors may be indicatively assumed in gross to cause 15% of total pressure losses in a piping section. Parameters of thermo-valves and valves on distributors can be obtained from the appropriate graph. The project does not have to contain a detailed list of material since it is no problem for an experienced plumber. It can also be obtained immediately as a free of charge service at the REVEL Company.
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