The first in-depth review of the Synseal Warmcore Door

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Nick Dardalis

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In mid–2015, Synseal Extrusions launched the Synseal Warmcore folding door as a bifolding product.

The Warmcore range of bifolding doors, residential doors and window come via a network of manufacturers and installers all over the UK.   This review of the Synseal Warmcore Door examines this hybrid aluminium product in a competitive bifolding door sector.  We have seen several variations of the Warmcore folding door in showrooms and residential installations and it’s an attractive product with some good features.

synseal warmcore door
Warmcore is a latest generation aluminium system with a PVCu thermal core with excellent thermal performance.

Who’s behind the Synseal Warmcore door?

Synseal is a long established and highly reputable company behind some of the best known products in PVCu. Originally the Warmcore name was teased into the market place whilst Synseal worked behind the scenes on creating a radically different bifolding door.

The result was the launch of the Warmcore bifolding door in aluminium from Synseal, a PVCu focused company.  Synseal is definitely marketing the product as an aluminium bifold.

Update January 2019.

This article was written in 2016 and in that time the product is widely available from many installers and manufacturers.  There are also negative Synseal reviews which we give an explanation of,  also connected with the Warmcore product. Many of these bad reviews are also not the fault of Warmcore or Synseal, but down to incorrect manufacturing and installation.

Moving aluminium thermal efficiency up a gear.

You will see on our website and elsewhere that the Synseal Warmcore door is marketed as the latest generation ‘warm aluminium’. Synseal say in their promotional material that this is the 3rd Generation of thermal break aluminium.

  • The first generation being a pour and cut thermal break.
  • Second generation is the current polyamide thermal break.

As well as good design and an overall attractive appearance, the thermal performance of Warmcore is what is heavily marketed by Synseal.

Does high thermal efficiency matter to consumers?

In designing any door product systems companies have to strike that fine balance between not only an energy efficient door, but one that is also aesthetically pleasing.

There is little point in designing a highly insulated product if this essentially hidden feature makes for an ugly door.

Consumers are generally guided by aesthetics first and foremost when choosing a bifolding door. If they’re happy with how a product looks they can then move onto other reasons to by such as security and thermal performance.

The vivid orange core found in Warmcore doors.

the substantial non metal core of the new warmcore door.
The substantial non metal core of the new Warmcore door.

Study the product closely as we have and the first thing that is evident is the warm orange core of the product.

On the small samples provided by the company, this orange heart of the extrusion is very evident. It is worth noting though that this will normally be invisible on a closed door and when the door sashes are in place.

So it is this vivid orange core that is behind the impressive thermal performance of the Warmcore door. On many bifolding door systems, a U-Value of 1.8Wm2K is typical. Warmcore doors improve on this further with a low U-Value of 1.4Wm2K when using 28mm units.

Glass specifications for the Warmcore Door.

It is Celsius Glass that Synseal recommend is used on the Warmcore door. Celsius comes designed for vertical glazing applications. Consequently, this is just like any other high specification quality glass unit. It uses a Low-E and Solar control coating as well as Argon gas fill between the panes of glass. Celsius also contains Easy Clean technology as well.

When used with triple glazing the product achieves a typical U-Value of 1.0 Wm2K.  Therefore if you’re looking for a highly thermally efficient door Warmcore presently is one of the best in the market with standard double glazed units.

Design Options on the Synseal Warmcore Door.

As expected from a modern-day bifold, options include a large number of opening and folding configurations.  Furthermore, doors open in or out and come with up 7 door panels as a 6-metre width bifold.

For taller doors, the Warmcore product can be manufactured up to 2400mm high and a maximum sash width of 1000mm high. This surpasses the typical 900mm width found in a PVCu door but still falls well below the 1200mm maximum width you can enjoy with a Schuco door as one example.

It is normal that many modern extensions also feature other types of doors. Therefore you can add single doors or French doors to the mix that are also available as a Warmcore door.

Better still and unlike many other bifolding doors, there is also a midrail option. We can’t see the value of a midrail in residential installs but there is certainly scope for doors with midrails in commercial applications.

Colour options with the Synseal Warmcore bifold.

Synseal have cleverly considered their other products with the Warmcore. The standard white and cream finishes available are designed to match the Synseal PVCu and orangery systems. Also on offer is RAL 9005 black and Grey RAL7016. Both of these are very popular colours with homeowners.

Special colours are available as are dual colours. Both of these options will be on special order.

Why we recommend Synseal Warmcore for external styling.

Many best selling bifolding door products are only available with either one or two profile choices. Synseal have considered the diversity of the homeowner market and this is where their PVCu experience is evident.

With the Warmcore door there are four different external features, specifically Pencil Round, Chamfered, Square as well as Decorative.

Having seen the Warmcore door this is a great move on behalf of Synseal. Our view is that many bifolding door and window providers forget the complete home solution. This is being able to offer a product to meet most customer requirements.

The Origin bifolding door, for instance, is an excellent product but is only offered with one frame and sash option. Their new Twin flush window is also excellent amongst aluminium windows. However it only offers a slimline slimline option when fitted to new openings. Where it’s used for replacement windows an add-on needs to be provided.

The point here is that bifolding door providers must remember that bifolds (and windows) don’t only go into new extensions and new openings. More often than not a bifolding door is fitted as a replacement to old French doors and sliding doors. A homeowner should have choice in what frame types are possible and this should be no different for bifolding doors.

Therefore if you’re looking to offer a bifolding door with up to four different frame designs, Warmcore will meet your needs.  Moreover, Warmcore offers you three different bead types as well. You can choose form Square all round, Chamfered or beads for triple glazing.

Finally, you’ll find a low threshold option. Interestingly this doesn’t feature a warm core but chooses to retain the polyamide thermal break instead.

Other features of the Warmcore bifolding door.

We won’t delve to deeply into the security and construction elements of the door. Suffice to say the door has been tested to Secured by Design/PAS 24 standards, offers great weathering and the hardware we can tell you is of exceptional quality on the finished product.

The installer benefits as well. The gaskets feature a great corner moulding helping sash to sash and sash to frame situations giving a really neat and tidy appearance. This does away with the overlap often found on gaskets glazed on site.

Some bifolding door providers fit hinges to their doors, others don’t. Warmcore doors come with clip fit hinges making site fitting a breeze. The double pivot rollers, bearings and other hardware on the doors have a really good solid and quality feel to them.

In operation we have found the doors easy to open and close. The main door handles and intermediate leaf handles look great, have a real quality finish to them and the operation of the doors is superb.

french doors in aluminium.

Do we recommend the Warmcore door?

We have had experience of virtually every bifolding door on the market from some of the best known names. We regard the Warmcore door as a real contender at the quality end of the market but at lower prices.

Whether the Warmcore door is an aluminium clad PVCu door or a true aluminium door is not really the issue. It is true other aluminium systems offer far more metal in their construction. However, thermal breaks are getting larger and aluminium profiles getting less as both windows and doors strive for greater thermal efficiency.  This does not mean that the Warmcore door is a lesser product. Synseal have chosen to market the energy efficiency of the product as one of it’s key features and there is no better insulator than a thick core separating the inner and outer aluminium profiles. You’ll arguably find the Warmcore door warmer to the touch as well perhaps.

The cladding of PVCu with aluminium is not new. WERU do it, Smart Systems for years had a really great Duotherm range which was similar. But above that, the Warmcore door looks really good, performs great and backed by one of the leading Systems Companies. Therefore if you’re looking to add another bifolding door product to your range, we recommend it.  Warmcore Windows also provide a thermally enhanced flush casement window to the product range.

If you’re a homeowner or an installer and would like further information on the product and where to buy it, please contact us.

(Images courtesy of Synseal Systems).

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