# Thermal transmittance of windows

Factor penetrations warm windows defines degree penetrations warm via whole fitting windows. Im less value of this parameter, including better insulation partitions insulation. Discussed here coefficient carries name Uw i is calculated on based on design mathematical.

Latest standard penetrations warm defines Revised Directive European 2010/31/EU, which establishes standard WT 2021, which for ordinary windows  not should cross Uw=0.9 W/m²K, a then Uw=1.1 W/m²K. for roof windows. Above requirements results z necessity building systems consuming very little energies. Information these are very important for persons planning construction or refurbishment buildings i should include new standards w prepared projects.

## How to calculate the Uw coefficient of a window?

The Uw coefficient for windows is calculated from the formula:

Uw=((Ag*Ug)+(Af*Uf)+(Ig*ψg))/A

for which:

Ug - heat transfer coefficient of the glazing

Ag - area of the glass pane

Uf - frame thermal transmittance

Af - area of the frame

Ψg - linear heat transfer coefficient due to the combination of the glass, spacer and frame

lg - length of the linear thermal bridge between the glass and the frame

A - total window area

The coefficient value is given in the unit W/m²K.

## Which windows to choose, taking into account their thermal transmittance?

Im lower coefficient penetrations warm windows, including better are its properties Protective. Issue this is relevant primarily all Therefore, that savings can be obtain mounting windows, which provide high insulation thermal.

What coefficient penetrations warm windows select Im lower temperature on Outside, including larger losses Heat. Therefore windows please choose w dependencies from conditions Environment, on which we can be exposed via whole year. In winter temperatures on our widths geographic may drop To About -30°C. Therefore worth invest w windows o coefficient penetrations warm 0,6-0,8 W/m²K.

What specifically window select Z our experiments results, that best solution are windows wooden or windows wood and aluminium. Use of sustainable, natural materials it's great option, which will keep its properties via many years. Z second pages, additional strengthening aluminium is justified, if target is increase Security windows.

As specialist w its field z pleasure will fly latest solutions z our offers product. Windows passiveo windows o lowest coefficients penetrations Heat. We call this model passive, because coefficient Uw is 0,68 W/m²K. Confirms it's top standard certificate insulation. If looking for specific solutions, necessarily see get z our offers. We believe, that models windows available on this website meet needs even most advanced projects architectural.

## What affects heat loss in windows?

Main cause losses warm w windows are leaking windows. What is cause After First, use of materials low quality i unstable. If material has high coefficient expansion thermal, its dimensions may amend get at impact temperatures. Window displayed in summer on sun expands get, a in winter shrinks. Even 1 mm deflection edges maybe cause escape Heat. Another reason is inappropriate installation i insulation woodwork windows. Even most expensive i best window not will meet its tasks, if not will be properly mounted.

Warm installation windows is not only compatible z standards, but primarily all very economic. Thanks to such as solution significantly reduces get penetration warm via windows, what runs To savings economic i significantly increases comfort stays w premises.

## Heat transfer coefficient - why is it important?

Factor penetrations warm windows is parameter strictly linked z applicable standards technical. Modern architecture obliges owners To use of energy efficient solutions, a producers To manufacturing such products. But w these regulations not has nothing bad. W longer perspective money remain w home cash registers. Windows o low coefficient penetrations warm are not only friendly for environments, but also economic. Worth consider it's as investment, which fast get returns i maybe save a lot money w string several years. Looking for energy efficient windows To its home? Do you have other questions? Contact get z us. We can help Ci select best solution.