Vaillant refrigerant pipe 3/8" (9.52 mm) - 25 m, insulated

Product detailed description

Vaillant refrigerant pipe 3/8" - 25 m, insulated

This 25-metre variant of insulated copper refrigerant pipe with a diameter of 3/8" (9.52 mm) is designed for installations of Vaillant climaVAIR air conditioning systems where the distance between the outdoor and indoor unit is greater than in a typical apartment installation - typically in larger family houses, when the outdoor unit is placed on the roof or on the opposite side of the building, or when the route runs through several floors. Depending on the specific pair of units and power class, the 3/8" diameter is used either as the gas or as the liquid branch of the refrigerant circuit - check the exact assignment in the installation manual of the given combination of units.

Thanks to the 25-metre length in a single package, you avoid the need to join several shorter pieces of pipe on most longer runs, which reduces the number of potentially risky points (joints) along the route and simplifies installation. The pipe is factory-fitted with thermal insulation along its entire length, which prevents heat loss and condensation of air moisture on the pipe surface.

Technical parameters

When to choose the 25-metre package instead of the 10-metre one

For standard apartment installations with a short run between units (up to approx. 8-10 m), the shorter 10-metre package of this diameter, also part of our range, is sufficient. For family houses where the outdoor unit is placed on a façade further away from the indoor unit, where the route runs through several floors, or where obstacles need to be routed around (building corners, utility rooms), it is worth choosing the 25-metre package straight away - this saves both cost and time associated with joining shorter pieces and reduces the number of joints, which are the most common source of leaks in the refrigerant circuit.

We recommend measuring the actual route before ordering, including allowances for bends, passage through the building envelope, and a slight surplus in case the route needs adjusting during installation - it is better to have a few extra metres to cut off than to join the route from two shorter packages.

Installation principles when working with refrigerant pipe

Cutting the copper pipe to the required length must be done exclusively with a copper pipe cutter, not a saw, so that the edge remains perpendicular and free of burrs that could damage the seal of the flare joint. After deburring, a flare cone is formed and the connection is made with a flare nut on the unit's service valve, tightened with a torque wrench to exactly the prescribed torque. Before charging with refrigerant, the circuit is purged with nitrogen, followed by a pressure test and finally evacuation to the prescribed vacuum level - these operations, as well as the actual refrigerant charging, may only be carried out by a company authorised to work with F-gases.

For longer runs, for which this 25-metre package is typically intended, pay increased attention to continuous fastening of the pipe along its entire length (at regular intervals depending on the weight and diameter of the pipe), so that the long run does not vibrate during compressor operation and does not stress the flare joints at either end. It is equally important to ensure smooth bends without kinks along the entire length of the route and watertight, insect-proof grommets at every passage through the building envelope.

Frequently asked questions

Is 25 m enough even for a larger family house?

For most family houses, yes; for exceptionally long runs (for example, an outdoor unit on a distant outbuilding), the route needs to be measured in advance and, if necessary, two packages joined together.

Is the 3/8" diameter the gas or the liquid branch?

It depends on the specific model and power class - check the installation manual of the given pair of units.

What if 25 m is more than I need for a 15 m run - can the rest be used elsewhere?

Yes, the surplus part can be cut off and used for another smaller installation or kept as a reserve for a possible future system extension.

Is the pipe already insulated?

Yes, factory-applied insulation along the entire length.

Storage and handling before installation

Until installation, keep both ends of the pipe sealed as delivered by the manufacturer, so that no moisture or dirt gets inside. Due to the greater length and therefore larger coil size of the 25-metre package, expect greater space requirements during transport and storage than with the shorter 10-metre variant of the same diameter.

Why choose genuine Vaillant pipe

Complying with the manufacturer's prescribed diameter, wall thickness and insulation quality is a prerequisite for maintaining the warranty on the air conditioning system and achieving the unit's declared output. For longer runs, for which this package is intended, correct pipe sizing has an even greater impact on overall system performance than on short runs, since pressure losses and heat losses increase proportionally with the length of the run.

Joining and shortening the route

If even 25 m were not enough for an exceptionally long run, packages are joined using copper connecting material while purging the inside of the pipe with nitrogen at the same time, to prevent scale forming on the inner surface of the pipe. Conversely, for a shorter run, the surplus part is simply cut off with a copper pipe cutter - with the 25-metre package, this situation is more common than the need for joining, since it is the standard longest available variant of this diameter.

Leak testing and safety

After installation, all flare joints are checked for leaks using a foam-forming detection spray or an electronic refrigerant leak detector. For longer runs, we recommend paying particularly thorough attention to leak testing at every passage through a wall or ceiling, as these points tend to be more prone to mechanical stress on the pipe during construction work around the grommet.

Warranty and compatibility

The pipe is supplementary installation material for Vaillant climaVAIR systems, covered by a standard 2-year warranty period. Using pipe that meets the manufacturer's specification is a prerequisite for maintaining the warranty on the air conditioning unit as a whole.

Extended FAQ

Can this pipe also be used with other air conditioning brands?

Yes, it is standard ACR copper pipe with a common 3/8" diameter, also compatible with other brands using the same diameter for the given branch - always check the prescribed diameter in the installation manual of the specific unit.

Is it worth buying the 25 m package straight away, even for a shorter run, just to be safe?

If you are unsure about the exact route length, it is a sensible choice - surplus pipe can easily be cut off and stored as a reserve, whereas additionally buying and joining a second package after underestimating the length means an extra joint on the route.

Does the pipe need any preparation before installation?

No, it is delivered ready for installation - degreased on the inside, with sealed ends. It just needs to be cut to the required length, flare cones formed, and connected to the units.

Material and temper of the copper pipe

This is high-purity ACR copper, degreased on the inside straight from the factory, supplied in soft (annealed) copper form, which can be manually shaped into gentle bends. For tighter bends on a longer run, it is recommended to use a pipe bender to avoid flattening the cross-section at any point along the long run - even a local narrowing of the cross-section affects the pressure drop over the entire length of the pipe.

Effect of pipe diameter and length on system performance

For longer runs (25 m and more), correct sizing of the pipe diameter becomes increasingly important, since the pressure drop and heat losses are proportional to the length of the run. For this reason, for some combinations of power class and route length exceeding a certain threshold, the manufacturer also prescribes an adjustment to the amount of additional refrigerant charge compared to the base amount stated for a standard (shorter) run - this assessment is part of the installation manual and should be carried out by a company authorised to work with F-gases before the system is charged.

Which pipe diameter and length do I need

In this category you will find Vaillant refrigerant pipe in diameters of 1/4", 3/8", 1/2" and 5/8", in lengths of 10 m and 25 m. This product - 3/8" in a 25-metre package - is designed for longer runs at lower and medium power classes. Don't forget to also order the corresponding second branch of the refrigerant circuit (opposite diameter according to the installation manual of your specific pair of units), ideally in the same 25-metre length, so that both branches run alongside each other without the need to additionally join one of them.

Comparison with the 10-metre package of the same diameter

Delivery and packaging

The pipe is delivered wound onto a coil sized appropriately for the longer package length, packed in protective packaging that protects the insulation from abrasion during transport. Given the larger size of the 25-metre coil compared to the 10-metre package, we recommend allowing for delivery by courier directly to the address rather than a pick-up box when ordering, in case the package size exceeds the chosen carrier's limits.

Recyclability and the environment

Copper is a fully recyclable material - take offcuts from shortening this longer coil to the required length to a recycling centre or scrap metal buyer instead of disposing of them in regular waste. With the 25-metre package, where surplus length is cut off more often than with the shorter 10-metre variant, it is worth collecting offcuts continuously and handing them in together once the entire installation is finished.

Route planning for multi-storey and larger installations

For routes running through several floors (for example, an outdoor unit on the roof and an indoor unit on the ground floor), it is important to consider not only the horizontal but also the vertical distance between the units - the manufacturer's installation documentation states the maximum permitted total height difference for the given combination of power class and route length. When designing the route, it is recommended to choose the most direct path possible with minimal unnecessary detours, since every additional metre of route increases the pressure drop and slightly reduces the efficiency of cooling or heating output transfer between the units.

When the pipe passes through several rooms or floors, remember to provide continuous mechanical protection of the pipe (for example, with a plastic or metal channel) at points where it could be exposed to mechanical damage - especially when routed through technical shafts together with other utilities or through communal areas of an apartment building.

Common mistakes when installing longer runs

Longer runs are more prone than short installations to insufficient continuous fastening of the pipe - on a long run without enough clips, the pipe can vibrate during compressor operation, which places long-term stress on the flare joints at both ends of the run. Another common mistake is underestimating the length allowance when ordering, which leads to emergency joining of a piece from another package instead of the planned use of a single continuous length of pipe. We therefore recommend actually measuring the route before ordering, including all bends and passages, with an allowance of approximately 1-2 extra metres.

Summary - who this product is for

The 3/8" refrigerant pipe in a 25-metre package is intended primarily for installation companies and technicians carrying out climaVAIR unit installations for longer runs - typically in family houses where the distance between the outdoor and indoor unit is greater, or for routes running through several floors. Don't forget to also order the corresponding second branch of the refrigerant circuit in this pipe, in the opposite diameter according to the installation manual of your specific pair of units - this category also includes diameters of 1/4", 1/2" and 5/8", in the same 25-metre length as well as in the shorter 10-metre package.

If you are unsure about the exact combination of diameters for your specific set of units, or need advice estimating the route length, contact our customer service - just state the specific outdoor and indoor unit models and the approximate distance between them, including any height difference, in your enquiry.

Effect of temperature fluctuations on long pipe runs

Copper pipe expands and contracts slightly with temperature changes, which is more pronounced for longer runs (25 m and more) than for short sections. When the pipe is routed through outdoor areas exposed to direct sunlight or large seasonal temperature swings, it is therefore advisable to leave gentle bends in the route instead of a completely straight run - these partially compensate for the linear expansion of the copper and reduce stress on the fastening elements as well as on the flare joints themselves at the ends of the run throughout the service life of the installation, which, with a well-executed installation, generally exceeds the typical service life of the air conditioning unit itself, including any later replacements.