Not all windows are the same...

Transcription

1 Buyers guide

2 Not all windows are the same... This guide has been compiled to help you make an informed decision when selecting and purchasing your new windows and doors. Everybody will tell you that their product is the best. We feel the information contained in this guide can help you understand the differences between windows and help you choose what is right for you. If you do not find the answers you need in this guide or if we can help you any further, contact us on LoCall: , or visit

3 What does U-Value, Solar Gain, A-Rated mean? U-Value Essentially a U-Value is a measure of a windows ability to keep heat inside your home and cold out. The lower the U- Value the more heat you will keep in your home. A low U-Value means less waste of the heat you pay for and less carbon emissions. Solar Gain/Solar Factor Solar Gain is a measure of a windows ability to transmit free heat from the sun into your home. A higher Solar Gain value is better, but this means nothing if you have a high U-Value, the free heat gained will go straight back out your window. A high Solar Gain can also lead to over heating in summer when you don t want any heat. A-Rated Windows can be rated against an energy efficiency scheme (WEP in Ireland, BFRC in the UK). These schemes are a consumer aid but they are flawed, you can have a good A-Rated window and a bad A-Rated window. Manufactures can achieve A-Ratings in different ways You can have a high U-Value, compensate with a really high Solar Gain and still achieve an A-Rated window. Glass is the most efficient part of a window, you can use lighter frame profiles to get more glass in and achieve an A- Rated window. This is not good for durability or longevity. Steel is a must for the structural integrity of a window, yet by taken it out or replacing it with PVC you can achieve a better energy rating. If a Rating is not independently certified, it doesn t mean anything!

4 What should I look for in a window? Low U-Value -better energy efficiency Insulated frames -better energy efficiency 100% Steel Reinforced frames -a must for durability and longevity without steel a window has no structural integrity, also handles, hinges and locks are screwed only to PVC and will loosen over time. Low-Emissivity soft coated glass -better energy efficiency Warm Edge spacer bars -better energy efficiency Argon gas filled glazing units -better energy efficiency Double sealed glazing units -durability and longevity Zero air leakage -better energy efficiency Internally glazed -better security Welded joints -durability and longevity Heavy duty hinges for triple glazed -durability and longevity Shoot bolt locking systems -better security Stainless steel hinges and hardware -durability and longevity Independently certified & tested -peace of mind - energy performance - certified for BER assessment ( Building Energy Rating ) - security, durability, weather resistance

5 What should I avoid in a window? High U-Value -increased heat loss No Insulation -increased heat loss No Reinforcement or PVC Reinforcement -structurally weak Hard coated glass -increased heat loss Aluminium spacer bars, Foam spacer bars Air filled glazing units -increased heat loss -increased heat loss Hot melt glazing units -structurally weak Co-Extruded profiles, Glazed or Frame vents -increased heat loss through draughts Externally glazed -less secure Mechanical joints -structurally weak Not independently certified & tested - energy performance - not certified for -no peace of mind BER assessment ( Building Energy Rating ) - security, durability, weather resistance

6 Are all glazing units the same? No - all glazing units are not the same, all double are not the same and all triple are not the same. How good a glazing unit is will not only depend on what materials it is made with, but also how it is made. Hermetically Sealed Insulating Glass Units This is the technical term for a double or triple glazing unit. The two key terms here are hermetically sealed and insulating. Hermetically Sealed There are two types of seals Cold Fusion and Hot Melt, in our opinion a Cold Fusion seal is better because it offers two seals to the glazing unit and can only be manufactured using a ridged spacer bar which again is better. Hot Melt units are cheaper to manufacture, have only one seal and use a foam spacer bar. If a unit is not sealed perfectly and built to last it will not perform efficiently and ultimately will fog up. Insulating Convection is the transfer of heat through the movement of gas, different types of gas are used to fill glazing units and prevent convection. Argon and Krypton are the two main gases used, Krypton is a lot more expensive than Argon and only performs better in a narrower cavity. The chart below shows the cavity widths where the different gases perform best.

7 The U-Value of a glazing unit will depend on many things type of glass used......low-e soft coat, low-e hard coat, low iron, etc. type of spacer bar used......warm-edge spacer, aluminium spacer, solid or desiccant filled type of gas used to fill the internal cavities......argon, krypton or air width of the internal cavities , 16, 20, etc. number of internal cavities double, 2 triple, etc. type of sealant used to seal the unit......polysulphide, polyurethane As with windows, the lower the U-Value the better the glazing unit will perform. Glazing units with a 0.6 U-Value for triple or 1.1 U-Value for double will give you the best overall window performance, but only when combined with a good quality insulated frame. We recommend 0.6 triple or 1.1 double glazed with... low-e soft coat glass argon filled warm-edge spacer cold fusion - double sealed

8 What type of windows should I buy? The following is a list of different type of windows and how they compare against each other when glazed with 0.6 U-Value triple glass units. (PVC Sliding Sash U-Value double glass units, triple not available). As you can see from below the frame type is very important and upvc not only performs the best but it is also the most cost effective. upvc Casement U-Value ( with 0.6 U-Value Glazing ) air leakage =0 cost 250 ( approx.900w x1400h ) annual energy cost maintenance cost - none life span - 30 years+ upvc Sliding Sash U-Value ( at best with 1.1 U-Value Glazing ) air leakage >0 cost 530 ( approx. for double glazed 900w x1400h ) annual energy cost maintenance cost - none life span - 20 years Timber U-Value ( at best with 0.6 U-Value Glazing ) air leakage >0 cost 410 ( approx.900w x1400h ) annual energy cost maintenance cost - high life span years Alu-Timber Clad U-Value ( at best with 0.6 U-Value Glazing ) air leakage >0 cost 480 ( approx.900w x1400h ) annual energy cost maintenance cost - moderate life span - 20 years Aluminium U-Value ( at best with 0.6 U-Value Glazing ) air leakage >0 cost 550 ( approx.900w x1400h ) annual energy cost maintenance cost - none life span - 30 years+

9 What are the savings? Not buying the right windows will ultimately cost you money. Inferior windows will need to be replaced sooner and less energy efficient windows will cost you money every day, below is a chart of annual saving based on today s fuel prices that can be achieved by selecting the right windows. We believe that the following specification is the way forward for energy efficiency, comfort and real savings for years to come. Walls Windows Ventilation U-Value U-Value - Heat recovery system (min 3 air changes per hour) The above will give you negligible or zero heat bills. Remember the lower the U-Value the more heat you will keep inside your home. An A-Rating is useless when a window has a high U-Value. Annual Energy Cost is based on the difference between installing 20m² of 0.8 U-Value PVC casement windows versus installing 20m² of the other options at current energy rates, does not include factors for air leakage or any provisions for carbon taxes.

10 What does Grady Joinery recommend? Elegance ZE 0.8 U-Value triple glazed upvc windows Independently certified by NSAI ( N ational Standards Authority of Ireland ) More economical today, tomorrow and for the next 30+ years Less than a 5 year payback

11 Why choose Grady Joinery? Lowest window U-Values Industry leading products Affordable 30+ years experience Nationwide sales and installation Independently certified Independently tested Comprehensive backup service and warranty Low lead times Directly employed Installers Directly employed Service Engineers Irish owned Family owned Irish Jobs Environmentally conscious Reputable Customer focused

12 Locall tel: +353 (0) fax: +353 (0) Unit 7G, Science & Technology Park, Mooneycooley, Maynooth, Co. Kildare, Ireland. GPS Co-Ordinates: , Charlestown, Co. Mayo, Ireland. GPS Co-Ordinates: , [email protected] [email protected]