Table of contents:

Laying heating pipes: you have to pay attention to this
Laying heating pipes: you have to pay attention to this

Video: Laying heating pipes: you have to pay attention to this

Отличия серверных жестких дисков от десктопных
Video: How to lag your pipes 2023, February

Planning and laying the heating pipes is a task with a lot of responsibility. After all, who wants to sit and freeze in their own home in winter? As a handyman, however, you cannot and may not do every work step yourself. However, with care and patience, you can reduce the installer's invoice total somewhat and help the heating expert. Here you can read what you have to consider when laying heating pipes.

Table of contents Table of contents for heating pipes: planning, material tips and laying

  • Where do the radiators go?
  • Differences between the laying systems
  • Material for the heating pipes
  • The right pipe diameter
  • Calculate the length of the heating pipes
  • Material for laying the heating pipes
  • How do you lay heating pipes?
  • Insulate heating pipes
  • Costs for laying heating pipes

Table of contents Table of contents for heating pipes: planning, material tips and laying

  • Where do the radiators go?
  • Differences between the laying systems
  • Material for the heating pipes
  • The right pipe diameter
  • Calculate the length of the heating pipes
  • Material for laying the heating pipes
  • How do you lay heating pipes?
  • Insulate heating pipes
  • Costs for laying heating pipes

Where do the radiators go?

Before you install the heating pipes, you need to know in which room and where a radiator is to be installed - the planning of the piping system is based on this. After all, the plump heat from the heater should be transported to the last radiator. Planning is usually carried out by the architect or the installation company - they also know how the radiators must be dimensioned and where the central control system must be installed so that each room can be heated well and inexpensively.

A basic distinction is made between a star-shaped and a ring-shaped arrangement of the heating pipes. In a bungalow house or apartment, experts prefer the star-shaped arrangement. In a multi-storey house, the pipes are usually arranged in a ring. So that the upper floors can also be heated well, you must use so-called risers. These are heating pipes that are installed vertically on or in the walls. In an apartment building, there is usually a combination of both systems.

Differences between the laying systems

But what is the difference between a star and a ring arrangement of the heating pipes? As the name suggests, all heating pipes run in a star or sun shape from the distributor directly to the radiators. The distributor is the starting point here and each radiator is supplied with hot water directly.

With the ring-shaped arrangement of the heating pipes, the radiators are connected to a circumferential pipe system. At the level of each radiator there is a connecting line between the ring-shaped supply line - the so-called flow - and the radiator thermostatic valve. At the outlet of the radiator, the now cooler water flows into the return installed parallel to the flow and is pumped back into the heating system, where it is then reheated. The main difference between the two laying systems is that with heating pipes arranged in a star shape, each radiator has its own flow and return. With the ring-shaped installation, all radiators use a common flow and return - these must then be dimensioned accordingly larger.

In practice, there are often mixed systems. For example, if a single radiator is relatively far away from the others, it is usually advisable to connect it to the ring system with its own flow and return, because this reduces the installation effort.

The right material for the heating pipes

There are three materials that heating pipes can be made of: steel, copper and plastic.

Steel pipes: Steel heating pipes can withstand very high temperatures and pressures. But: They are susceptible to external corrosion and therefore not suitable for wet rooms and areas with high humidity. In addition, such heating pipes must be vented regularly. If air gets into the pipes, internal corrosion can otherwise occur.

Copper pipes: The copper heating pipes are easy to lay using so-called press connections, but are more suitable for small heating systems. They can handle temperatures up to 100 degrees Celsius, but can be modified to withstand 250 degrees Celsius. Copper pipes expand when the temperature changes, which in turn is their disadvantage. In addition, the material copper is relatively expensive. Copper pipes should be well insulated between the radiators because the material has a high thermal conductivity. Another advantage of the material: it is corrosion-free. Copper pipes occasionally form some verdigris on the surface in a damp environment, but this does not penetrate the material and therefore does not impair its function.

Plastic pipes: If you want to run your heating system as a low-temperature system at 80 degrees Celsius or less, plastic heating pipes could be the solution for you. With such a system, so-called surface heating systems such as wall heating systems or floor heating systems are operated. Plastic pipes are rust-resistant and energy-saving, but can expand if the temperature is too high. In addition, they are more flammable than metal pipes and do not withstand excessive mechanical loads.

Plastic-coated aluminum composite pipes: This hybrid of plastic and metal pipes is flexible and particularly easy to lay in difficult corners. Depending on the manufacturer, the tube can withstand up to 95 degrees Celsius and a pressure of 10 bar.

Heizungsrohre verlegen: Planung
Heizungsrohre verlegen: Planung

During the planning phase, you should make sure that the heating pipes in the house are laid economically so that no heat is lost.

Photo: iStock / frankoppermann

The right pipe diameter

The main pipes and the risers of the heating pipes should have a diameter of 26 millimeters. Heating pipes that are connected to radiators with a heating output of up to seven kilowatts need a diameter of 20 millimeters. Heating pipes for heating systems up to 3.5 kilowatts manage with a pipe diameter of 16 millimeters.

If you want to lay the heating pipes in a visually appealing way, you should opt for a so-called flush installation. It is best to have an expert mark the wall slots, because a certain standard (DIN-1053) must be observed, otherwise there could be static problems in the masonry. With a slot cutter set to the correct depth, you can then mill the slots yourself and save some money with this own contribution when building a house. In the basement and in the utility room, you should lay the heating pipes on the plaster - this is cheaper and they do not interfere optically here.

Heating pipes can also be laid in the occupied rooms without milling - in the baseboards. There are special deep skirting boards that cover the pipes invisibly. Remember that heating pipes must be insulated later, at least in a non-heated area. In this case, you have to leave more space in the wall and on the floor, so allow for a larger cross-section.

How many meters of heating pipe do you need?

Before you go shopping, you should clarify a question with the heating installer: How many meters do I need from which heating pipe? For this purpose, the distance from each radiator to the distributor or the heater is measured and doubled. After all, you need one pipe for the lead and one for the drain. Then the heating water flow is calculated. This is the part where, as a layperson, you can do a lot wrong - because if the heating water flow is calculated incorrectly, you will either hear the water in the pipes or the radiator can remain cold.

The different types of pipes, but also heating pipes of the same size, are plugged together with fittings. These are suitable for every pipe material and they must either be soldered (copper pipes) or screwed (steel, plastic). There are also corner and T-pieces as well as adapters to connect the heating pipes to existing heating systems. These important connecting parts are also on your shopping list. Of course, you only know exactly how many adapters, connectors, corner pieces and T-pieces you need once you have planned the exact course of the heating pipes.

Material for laying the heating pipes

You also need to install the heating pipes:

  • Soldering iron or welding machine
  • Solder paste
  • Pipe cutter
  • Thread cutter
  • Pipe wrench
  • Crimping pliers
  • screwdriver
  • Brackets for the heating pipes
  • Hemp for sealing
  • Pipe insulation
  • Hammer drill
  • Dowels

You can borrow the devices from the hardware store or maybe even from your heating installer. Which additional devices you need also depends on the type of heating pipe. It is best to speak to your sanitary installer - this will save you unnecessary rental costs.

How do you lay heating pipes?

Now it starts, the heating pipes are laid. Cut all pipes to the millimeter according to the installation plan and grind the cut edges before inserting the heating pipes into the fittings. In the case of screw connections, which are common for steel pipes, you have to cut an external thread into the pipes after cutting. Attention: For this it is extremely important that the heating pipes are cut exactly straight. Therefore, use a special pipe cutter or a hacksaw with a guide.

So you work your way piece by piece, lay the heating pipes meter by meter and connect the pipes with the fittings. Be careful not to mix up the feed and return. Helpful tip: Mark the future flow direction of the water with a red or blue felt-tip pen as an arrow on each pipe of the flow and return.

All connections must be professionally soldered, pressed or screwed with a suitable seal (special sealing cord or hemp fibers with sealing paste). Always wrap the cord and the hemp fibers clockwise over the threads after roughening them with an old saw blade. If in doubt, you should leave the soldering of copper pipes to a specialist, because without experience you can do a lot wrong here and cause unnecessary follow-up costs. A connection technology that is often used today is the pressing of the copper pipes with the appropriate fittings - you need a special electric crimping tool for this. The device can be borrowed from the hardware store.

When connecting the radiators, make sure to always connect the flow at the top and the flow at the bottom. Commercially available flat radiators usually have a connection on both sides at the top and bottom, so that you are flexible during installation - the openings that are not required are closed with a blind screw, on the rest you screw the flow valve with the thermostat and the drain valve, the is connected to the wake.

Important: Before you switch on the heating with the self-routed heating pipes, a plumber must inspect your work and carry out a pressure test. The test run should be carried out before insulating the heating pipes and plastering the wall slots. In an emergency, the professional can replace a heating pipe or repair a leaky connection.

For safety reasons, the heating system itself and all direct connections must be installed by a heating engineer in any case, since the risk of accidents is very high, especially with gas-powered heating systems. You should never install the central electronic control of a smart heating system yourself.

Insulate heating pipes

Your freshly installed heating pipes now run through the whole house. The longer the route of the pipes laid, the greater the risk that the water in the heating pipes will cool down - especially if some of them are in unheated rooms. This unnecessarily consumes the energy you pay for. The solution is very simple: insulate the heating pipes. Pipe insulation has been a legal requirement in all non-heated rooms since 2002 - how much you isolate from the rest is up to you. Also because the well-functioning and easy-to-install insulation systems are quite expensive. But don't forget that the costs will pay for themselves over the years.

So-called pipe shells made of polyethylene foam or rubber are usually used to insulate heating pipes. They are continuously slotted on one side, simply slipped over the pipe and closed on the open side with the pre-assembled adhesive flap or normal adhesive tape. Cut the pieces so that the pipe clamps are covered as much as possible. Rubber pipe shells are flame retardant, but also more expensive than the easily flammable PE pipe shells.

If you lay heating pipes on plaster on the cellar ceiling, in the attic or in other very cool rooms, you should use thicker pipe shells made of rock wool with an aluminum surface for insulation. Although they have a fairly large cross-section, they also isolate best. Also glue these pipe shells carefully so that no heat is unnecessarily lost in the basement.

When purchasing the pipe insulation, you should make sure that the pipe shells are marked with "ENEV100 percent". Buy a little more insulation than you calculated - a bit of shrinkage is normal. And if there is anything left, you can also use the pipe insulation for the water pipes. When cutting out the places where one pipe comes off another, make sure that you cut out the hole for the outgoing heating pipe perfectly. Otherwise heat and energy will escape unnecessarily.

Heizungsrohre isolieren
Heizungsrohre isolieren

If you insulate your heating pipes with insulation hoses from the hardware store, you save valuable energy.

Photo: iStock / undefined undefined

What does it cost to lay heating pipes?

Experts calculate the costs for a modern gas heating system with hot water preparation on average at around 7.5 percent of the total construction costs. The heating system itself, including installation costs, accounts for around 50 percent of this. The piping costs around 25 to 30 percent depending on the effort. The remaining costs relate to the house connection for the natural gas and the radiators. For an average family home, you have to plan around 15, 000 to 18, 000 euros.

Around 60 percent of the total is pure material costs, with 40 percent of the labor costs. In contrast, when installing the heating pipes, the pure installation costs are around 50 percent. So if you estimate this item at 4, 000 euros, you can save up to 2, 000 euros with your own contribution. Incidentally, the assembly of the radiators including material also costs around 4, 000 euros, with the pure labor costs also accounting for around 50 percent. So if you do all the work yourself except for the installation and connection of the heating system and the gas and water connection, you can save up to 4000 euros.

Sabrina Deckert

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