One of the key importance's when choosing new Double-Glazing is making sure your new windows and doors are energy efficient.
Each windows energy efficiency is usually measured in two ways with either with WER or U-value. 'WER' (Window Energy Rating) is broken down into A, B and C.
A Rated Windows Explained
Quite simply, A Rated windows are the best performing from a thermal performance and energy saving point of view. Investing in A-rated windows is highly recommended if you're planning on spending many years in your property.
Definition installs A-rated windows as standard, which also come with a full 10 year extended warranty for extra peace of mind. There are a few factors which make up a windows A-rating - but the main feature is the type of glazing.
All of our glazing is Argon-filled. What does this mean, and why does Argon play such an important role in the make-up of your new windows?
Put simply, if your new double glazed unit was not injected with Argon it would simply contain dehydrated air. Argon has 34% lower thermal conductivity than air as its density is greater. It helps to minimise the movement of warm air as a result reduce heat conductance between panes. This is great for double glazing because in the winter more heat is kept in and in the summer when it is warm outside Argon does not allow too much heat to pass through the unit making rooms unbearably hot. Argon is a brilliant addition to a high performing unit as it can improve double glazing’s U value or energy rating by over 30%, which is why we offer this as our standard choice of glazing.
All of our windows are available in Aluminium, uPVC or Timber - so speak to us for more details on the ranges we offer for our highest performance rating.
B Rated Windows Explained
Whilst still generating most of the energy-saving benefits A Rated windows have to offer, B Rated windows offer slightly less in terms of an overall return on investment - but are still an excellent choice for those looking to upgrade their double-glazing. The only real difference is that they are not quite as high performing as an A-rated window, but this being said, they are still highly energy efficient.
We recommend home-owners who are looking to invest in their properties and want the best long-term benefits opt for A-rated windows, whereas B-rated act as a great alternative for those who are simply renovating a property to sell on, for landlords who want a cost-effective option, or for those who have a slightly smaller budget for their double-glazing.
In summary - A Rated or B Rated windows both exceed energy standards for new double glazing, but the long term decision to consider is how much impact those windows will have in reducing energy bills, promoting heat retention and boosting sustainability and energy efficiency throughout the house. If you're going to be living in your house for quite some time, or it's a forever family-home - A-rated is the way to go.
U-Value Rating Explained
Another common measurement for Window Energy Efficiency is U-value. Thermal transmittance, also known as U-value, is the rate of transfer of heat through a structure (which can be a single material or a composite), divided by the difference in temperature across that structure. The units of measurement are W/m²K. The better-insulated a structure is, the lower the U-value will be. Workmanship and installation standards strongly affect the thermal transmittance, which is why we only ever install to an impeccably high standard - allowing for maximum energy efficiency to be achieved. If insulation is fitted poorly, with gaps and cold bridges, then the thermal transmittance can be considerably higher than desired - which is why it's important to ensure that all new windows and doors are correctly insulated, measured to precision, and fitted with accuracy.
An A-rated, double-glazed window should achieve an average U-value of 1.2W/m²K. Ask us for more details on U-values for our products if you wish to find out more.