THE BEST WINDOW FILMS FOR YOUR CONSERVATORY ROOF & CONSERVATORY WINDOWS

Does conservatory window film work? Read the reviews, choose the right conservatory roof film and you will soon be enjoying your conservatory in comfort.

 

 

 

 Solar Reflective Roof Film Reviews

Invest in a solar reflective conservatory roof film. However, it is important to identify exactly what you are trying to achieve.

For example, if you struggle with visual comfort, watch TV in your conservatory or use the space as an office then reducing light levels is important. Typically, you will need to reduce natural light by over 90 percent or risk being disappointed. We recommend Low Reflect Extreme as it effectively puts sunglasses on your conservatory whilst offering incredible heat rejection.

If the sun's radiant heat is the overriding factor, then the best conservatory roof film to tackle the sun's radiant heat is 3M All Seasons 35. It transmits 70 percent more natural light than Silver 20 whilst rejecting more of the sun's radiant heat. 3M added the window film to their All-Seasons series of solar window films because it takes the edge off winter heat loss too.

Many untrue and misleading claims are made about Reflective Silver 20 across the UK internet. For example, the real solar heat gain reduction is closer to half of the 82% claimed below. Over 40% is still a good performance.

Another company lists amazing performance figures alongside a caveat that the type of glass matters. This is very true. Performance figures tend to be based on single glazing whereas your conservatory roof is likely to be modern double glazing. This well-established company states the performance on different glazing systems will vary slightly,

The truth is that performance is halved. However, anything over 40 percent is good.

The Sun's Radiant Heat Can Be 10-20 Degrees Hotter Than The Air Temperature

Natural light will turn to heat but leads to a more gentle rise in air temperature. In our considerable experience, this can usually be handled by opening doors or windows.

The real problem is the sun's radiant heat (near-infrared) which can be 10 to 20 degrees greater than the air temperature.

A good example to illustrate this is to think of when you are in your car on a bright day. The air conditioning ensures the air temperature is fine, but the sun's sweltering radiant heat makes you feel like you are baking. Another example is when you compare being in the shade compared within the sun. The air temperature is the same, but the radiant temperature is incomparable.

Here are the performance figures for heat-reflective conservatory roof films. Note that most performance figures are published for single-pane glazing, this is the TSER (Total Solar Energy Rejected) column. Note that the real reductions are modelled on 4mm modern Low-E double glazing with a 10% air / 90% argon-filled 16mm cavity. The performance will vary according to the glazing system.

Does Conservatory Window Film Work?

You need to focus on reducing the sun's radiant heat first and foremost. This is the key driver of thermal comfort in the summer. Air temperature is a secondary factor that can be mitigated by opening a door or windows.

As long as you choose a reflective conservatory roof film then you will enjoy a significantly cooler conservatory. Better still is to choose a conservatory roof film like 3M All Seasons 35 which reflects significantly more of the sun's radiant heat than other films.

If glare is a big issue then you need to go for a conservatory roof film with over 90% glare reduction to comfortably watch TV or use computers.

Silver 20 is an effective budget film, but neutral conservatory roof films do not offer sufficient solar heat rejection.

Conservatory Window Film Reviews | The Side Glazing

About 40 percent of the sun's heat on a south-facing conservatory is through the side glazing. In the height of the summer, there is more heat through the east and west-facing windows compared with the south-facing windows.

Surprisingly, there is heat gain through north-facing glazing, especially in June at the equinox. This is because the sun rises in the northeast and sets in the northwest.

The conservatory offers the opportunity to connect with the outside. The ideal film for most clients would reject the sun's radiant heat and transmit lots of natural light.

3M Prestige 70 External Window Film

This is the pinnacle of conservatory window films for the side glazing. It is virtually undetectable. The 3M Prestige External Series of solar window films reject more of the sun's uncomfortable radiant heat, near-infrared, than any other conservatory window films.

It is applied to the exterior of the window and virtually eliminates the sun's radiant heat. So, if lots of natural light is important, and you value the living space your conservatory offers then this is your film.

Expect a reduction of solar heat gain on modern double glazing of between 40 to 44 percent. The gentle increase in air temperature caused by natural light can usually be handled by opening windows or a door.

Solargard SX50 and Other External Silver 50 Solar Window Films

3M Prestige 70 External rejects more radiant heat, transmits more natural light and lasts longer. However, this extraordinary package of benefits requires a bigger investment. External Silver 50 offers great value and performance. Expect a solar heat reduction of 45 to 50 percent. It achieves this by knocking out a chunk of natural light that would have turned to heat.

Darker External Solar Films

3M Neutral 35 External, 3M Prestige 40, Solargard Sentinel Stainless Steel and DX Ranges and Llumar's External Neutral films all boast decent performance. They are darker than the Silver 50 External and 3M Prestige 70 External.

The pick of the bunch is 3M Prestige 40 External which rejects about 55 to 60 percent of the solar heat gain and has excellent longevity.

Subtle Dual Reflective Internal Films

Solargard TrueView, 3M Night Vision and Llumar Dual Reflective ranges are all internal films that have a less reflective interior face with a more reflective external face. Their longevity will be good. The downside is that the performance of internal films is less effective than external films. Expect about a 20 to 35 percent reduction in solar heat gain on modern glazing.

Neutral Internal Films 

Avoid these. They simply do not perform on modern double glazing

Conclusion About Conservatory Window Films For The Side Glazing

WindowTreat recommends choosing an external conservatory window film to benefit from superior solar heat rejection, lots of natural light and a subtle non-reflective appearance.

How Much Solar Heat is Entering My Conservatory Roof?

Even a dripping tap will fill a bucket. The same is true for the sun's heat. Some ventilation is required to prevent the trapped heat from steadily increasing. Ideally, this is a vent or window in the roof, but it could be as simple as opening a couple of windows or the doors.

What follows is an analysis of the solar heat gain for a south-facing 15m2 Edwardian Conservatory in London with 6m2 of glass facing East, South and West. Not many people realise that there is solar gain through North-facing windows because the sun rises in the North-East and sets in the South-West.

July is the month with the highest solar heat gain. The key takeaway is that some solar heat gain is being reduced by the conservatory roof. In this case, the old double glazing reduces the solar gain by 25 percent and the modern Active Blue conservatory glazing reduces the solar heat gain by over 60 percent.

However, even with an equivalent of an Active Blue Conservatory roof clients still complain that they are too hot. This is in part because about half the solar heat gain is transmitted through the side glazing, which has not been treated.

How Much Heat Is Entering Through The Side Glazing?

Surprisingly, it is the East and West facing windows that have the most solar gain during the Summer months. This is because the sun is higher in the sky during summer in the South. Therefore, it is the East and West that contribute most to the peak solar heat gain and not the South as one might expect.

If this conservatory did have North-facing windows then it would have some solar heat gain in the peak of summer. This is because the sun rises in the North-East and sets in the North-West in summer.

Ovens, Electric Heaters and Toasters

The summer solar heat gain through the conservatory roof peaks between 2.5 Mega Watt Hours and 3.8 Mega Watt Hours in July. This is equivalent of three to four ovens or electric heaters running ten hours a day every day inside your conservatory. Or 7 to 10 toasters busy toasting for 10 hours every day.

For Active Blue and BioClean Conservatory Roofs

Choose a highly reflective conservatory window film. There is a section on the different choices of reflective conservatory window film later.

The roof is already doing a good job at preventing solar heat gain, but it will not necessarily cope with the demands of a very hot summer. If you do not want night-time reflections then consider 3M Night Vision 15 on the roof glazing. Lighter films than 3M Night Vision 15 will be a compromise on performance. Consider filming the side glazing with 3M Prestige 40 or 3M Prestige 70.

 

The Older Generation of Conservatory Roof Glazing Systems

The older generation of double glazing has no Low-E coatings or Argon filled cavities. They lend themselves brilliantly to any of the Reflective Conservatory Window Films.

We would recommend 3M All Seasons Amber, our most popular film for conservatories, to tackle more of the sun's uncomfortable radiant heat compared with Silver 20, Low Reflect or 3M Night Vision 15. The latter films are ideal for tackling glare.

 

The Conservatory Roof with Energy Efficient Glazing

These conservatories tend to have similar glazing on the side windows and the roof glazing. This means lots of natural light is transmitted through the glazing and often there is a glaring problem as well as a solar heat gain issue.

3M Night Vision 15 and Low Reflect 15 are both good films to tackle glare. However, if glare is not an issue for you then we recommend 3M All Seasons Amber.

 

Modern Side Glazing

The surprise here is that 3M Prestige 40 on the side glazing rejects more solar heat than filming the Active Blue / BioClean conservatory roofs and almost as much as filming the Energy Efficient Conservatory Roof. 3M Prestige 70 also impresses and is virtually undetectable. 3M Prestige 40 has a tint that most clients are happy with.

The other advantage is that furnishings and floors will stay looking newer for three times longer as the fading and damage caused by Ultra Violet radiation and the intensity of the sun's radiant heat are rejected by 99% and 97% respectively. 

 

Closing Thoughts

Ignore Product Specification Sheets as they show performance on single pane glazing and sometimes old types of double glazing. They do not quote performance for glazing in conservatories built after 2005.

Conservatory window film is a cost-effective investment in order that you can comfortably enjoy your conservatory for significantly more hours a day and weeks per year. Clients are delighted with the results. However, it is important to set expectations that a glass room cannot cope with the worst days during a heatwave even with the film.

If this is your expectation then we, at WindowTreat, are confident that you too will be happy with an investment in conservatory window film. Just get the right advice and support so that you end up making the right choice.

Our highly trained advisers are here to offer you the facts so that you can make the right choice for yourself.

01256 345580 or info@windowtreat.co.uk