What is Vacuum Insulated Glass and why does it need a Getter?
Vacuum Insulated Glass – also known as VIG – has a getter. What does this mean? In this post we’ll tell you all about Vacuum Insulated Glass and answer the question “Why does Vacuum Insulated Glass have a Getter?”.
What is Vacuum Insulated Glass?
Vacuum Insulated Glass is a type of double glazing that is built to be more efficient and better looking than standard double glazing.
You may be aware that double glazed windows are made from 2 panes of glass with a gap on the inside of the window between them. The idea is that the extra glass and the cavity between them improve the insulating and noise-reducing properties of the window.
Often the gap is filled with air. Improvements can be made by filling the cavity with a Noble gas such as Argon. This makes it harder for heat to travel through the gap. As a result, rooms are warmer and generally more comfortable.
Vacuum Insulated Glass takes the concept a step further by removing all of the air from the cavity. Unlike the Starship Enterprise, heat and sound cannot cross a vacuum thus making the windows even more efficient. Please note: it is extremely unlikely that you will find Captain Kirk in the gap in your double glazing, even if you do have vacuum insulation.
Benefits of Vacuum Glass
Vacuum Insulated Glass makes your house warmer. The windows are more efficient at keeping the heat in, and the cold out. The opposite effect happens in summer – homes with VIG are cooler than those without.
VIG is better looking than standard double glazed windows. Because heat and sound cannot cross a vacuum, and you can’t have more of nothing, then a tiny little gap with a vacuum is just as efficient as the vastness of space. The gap between the panes of glass in vacuum glazing is very small. The width of the cavity is typically just 0.3mm. Compare this to a gap of anything between 16 – 26mm in standard glazing, then you have none of the unsightly inner cavity linings on show.
Why does Vacuum Insulated Glass have a Getter?
The Getter is there to keep the vacuum pure. Not just a feature in windows, any environments that have a vacuum will probably have a getter. The getter is a substance that absorbs any gasses that might be contaminating the vacuum. The more pure the vacuum, the more efficient the windows are.
There are 2 types of getters for vacuums – a vapourised getter and a non-evaporable getter.
A vapourised getter is usually a tube, wire or sheet of volatile metal such as Tantalum, Colombium or Zirconium. The metal instantly reacts with any gas it comes in contact with, cooling and condensing it into a thin film.
Non-evaporable getters are much cleaner as they absorb the gas – the getter turns the gas into itself – and continues to operate. It’s these non-evaporable getters that are used in Vacuum insulated glazing as they don’t create condensation.
There are also temperature-controlled getters that only work within certain temperatures. Low-temperature getters work at room temperature and are used in vacuum glass. High-temperature getters have an optimal working temperature of around 400ºC, and even unsupervised teenagers struggle to turn the heating up enough to get rooms quite that hot.
How much does Vacuum Insulated Glass increase energy efficiency?
VIG has been found to make a significant contribution to increasing the energy efficiency of homes. Vacuum glass can be used to achieve passive house standards (super-efficient houses – you can read more about them here: https://www.gowercroft.co.uk/news/why-vacuum-double-glazing-is-best-for-a-passive-house-window/). Houses that meet passive house standards are up to 75% more efficient than other buildings. While it may not be possible to convert older houses to meet passive house requirements, improvements to insulation, including adding vacuum insulated windows makes a huge difference to gas and electricity bills for the owners.
Is Vacuum Insulated Glass worth the investment?
Yes. Homes are cheaper to heat, so the cost of installing more efficient windows is offset by the significant savings homeowners can benefit from, especially in mid-2022 where prices are rising dramatically.
VIG also makes home much better looking. Without that ugly cavity between the two panes the windows look more like single glazing. This combination of increased form and function makes them ideal for any home, and particularly suited to restoration projects and Listed buildings. These types of windows need special designs, known as Heritage Windows.
In summary – your home can be made prettier and cheaper to run by installing Vacuum Insulated Glass.