The advantages of effectively insulating a home are pretty clear — not only does it help to create a warmer, cosier environment, it can also make a big difference to heating costs. However, if you’re working with a particularly tight plot, or an area of your home where there really isn’t much room to lose internal wall space, installing high levels of insulation can pose a problem.

That’s where vacuum insulated panels (VIPs) come in — providing a radically different insulation approach which can significantly cut down build-up thicknesses.

What Exactly is a VIP?

When looking at a VIP, it’s immediately obvious that they are a little different to traditional insulation. Unlike the foam or fibre of traditional insulation materials, VIPs comprise a microporous core from which the air is removed, before it is encased and sealed within a gas-tight multi-layer foil envelope.

As anyone who’s ever used a vacuum flask on a windy hill side will know, this vacuum approach is a highly effective way of keeping heat in. In fact, with a typical aged thermal conductivity of 0.007kW/m, VIPs provide an insulating performance that is up to five times better than other common materials.

As the vacuum must be maintained in order for VIPs to function effectively, the panels must not be cut. To combat this, they’re typically supplied in systems with high or premium performance infill strips of the same thickness. These strips can be cut to the shape of any unusual areas or to allow for penetrations through the insulated surface (such as pipework).

The Quick Read

  • Vacuum insulation panels (VIPs) can match the thermal performance of other insulation materials at a fraction of the thickness
  • They can provide a useful solution in areas of the home where lack of space has previously made it difficult to insulate
  • They’re suitable for walls, roofs and floors, where thickness is a particular issue

Where Should They be Used?

VIPs are highly adaptable and, when installed with due care and attention, can be used in most areas of the building envelope. They are also particularly suited for floors, flat roofs (and roof terraces), dormer windows and in wall applications.

In many cases, VIPs are used to solve a particular problem area within a property. Take, for instance, an insulation refurbishment on a solid floored property. In order to accommodate the required thickness of traditional insulation, it is often necessary to manually dig out and remove a large volume of material, leading to increases in project times and cost.

For example, the minimum U value (thermal performance) target for refurbished floors under the Building Regulations in England is 0.25. To achieve this in a typical Victorian terrace with a 36m2 (perimeter/area ratio of 0.3) floor area, where the existing floor is being replaced, 60mm of expanded polystyrene insulation is needed. This requires 2.16m3 of ground material to be excavated by hand and removed from the site, greatly extending the construction programme.

concrete deck cover with VIP for insulation diagram

Kingspan’s vacuum insulation panels used in a floor build-up. Thicknesses would be between 40-60mm to achieve U values in the region of 0.15-0.2

In contrast, a VIP system including 15 per cent infill strips can achieve the required thermal performance with a thickness of just 26mm, meaning less than one cubic metre of soil needs to be removed. This speeds up the installation time and helps to minimise disruption for the homeowners while reducing construction costs. A further thickness of rigid thermoset infills should also be installed vertically around the floor edge to help limit thermal bridging.

The alternative for refurbishment projects is to raise the existing floor level. However, this will reduce the floor to ceiling height within the room and requires fixtures and services such as plug sockets, door lintels and radiators to be raised in line with the floor level, creating yet more remedial work and again increasing the time and cost involved. VIPs provide a slim-line solution, helping to keep projects on track without compromising head height.

man carrying Kingspan VIP insulation

Because vacuum insulated panels rely on the vacuum for their performance, they cannot be cut in the way that insulation usually can. They instead rely on additional infill strips to provide flexibility

Installation

While VIPs have only recently started to gain in popularity in the UK, they’ve been used successfully for many years on the Continent, particularly in Scandinavia, Germany and Switzerland.

Manufacturers will typically provide installers with clear instructions on how the product should be handled and installed to maximise its lifespan. In addition, to ensure the target thermal performance is met with the thinnest possible system thickness, free technical design services are offered by some manufacturers. The designers draw up VIP system layouts for each specific application, ensuring the best possible ratio of VIPs to infill strips.


adrianAdrian Pargeter

Adrian is Head of Marketing and Product Development at Kingspan Insulation and is one of the UK’s leading experts on insulation

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