PVC-U windows are used in 80% of the world, and for at least 50 years. PVC-U is much more energy efficient than aluminium. At 25°C aluminum thermal conductivity is 205 w/mk while PVC thermal conductivity is only 0.19 w/mk.
In a letter to BUILD magazine published in 2006, Ken Miller – a former President of the UK Federation of Master Builders wrote: ” After all, the Europeans have been building far longer than us and it’s about time we took a leaf out of their book. … Otherwise New Zealand will continue to build shoddy, leaking, damp and inefficient homes for years to come.” To download a full copy of his letter, click < Look to other countries to build wisely>.
Homerit PVC-U windows and doors are fitted with double glazing units from Metro Glass (www.metroglass.co.nz) . In addition to standard double glazing there are three types of Low E double glazing – Plus Low E, Max Low E and Xcel Low E. Low E is a coating on glass which can improve thermal insulation. 75% of our customers choose Low E double glazing.
WEERS is the official Window Energy Efficiency Rating System for comparing the performance of windows and doors. It uses a simple 6-star system to tell you how various window frame and glass options will perform. WEERS shows that PVC/Timber frame is the best while aluminium frame is the worst. 6 energy star rating requires thermal insulation R value 0.55 or higher.
R value of Homerit PVC-U windows and doors varies from 0.38 to 0.71 depending on the type of Low E glass and the window designs. Homerit PVC-U standard double glazed windows are rated 4 energy stars out of 6 under WEERS. Homerit PVC-U windows with Plus Low E double glazing are rated 5 and half energy stars out of 6. Homerit PVC-U windows with Max or Xcel Low E double glazing are rated the maximum 6 energy stars.
In each building, windows and doors play a decisive role for thermal insulation. With well-targeted measures you can exploit great energy saving potentials. Owing to the characteristics of PVC-U, Homerit PVC-U windows & doors have excellent thermal insulation properties. The material itself has lower conductivity compared with metal frames. Plus the multi-chamber system gives Homerit PVC-U windows & doors further insulation ability.