Performance of a pvc window in terms of heat and sound is based on the glass unit used by 70% as 70%-80% part of the pvc windows is formed of glass. Thus, it is considerably significant to pay special attention to the glass type in terms of the performance of the window while choosing pvc windows to be used in the residence or work places.
Criteria to which special attention should be paid while choosing glass can be listed as follows:
1. Glass Dimension
Glass units used today are classified as double-glazing or triple glazing. Double-glazing units are formed by assembling two panes of glass to each other with selected interstitial space dimension. Triple glazing systems are the systems with which higher insulation values are obtained through two different spaces left among 3 panes of glass.
Double Grazing Unit
Triple Grazing Unit
Glass dimensions are given as 1st glass thickness + interstitial space + 2nd glass thickness. For instance; with regard to a glass of 4 + 12 + 4 mm, 1st glass thickness means 4 mm, interstitial space between two glasses 12 mm and 2nd glass thickness 4 mm. Interstitial spaces are commonly 12 mm or 16 mm. The more the interstitial space, the more the insulation value of the glass. In addition, air or argon gas can be used as a filling between two glasses. When argon gas is used, higher insulation values are obtained.
2. Glass Unit Types
Glasses used in PVC window systems vary with regard to the purpose of use. Thus, using the favorable glass in the right place will prevent increasing investment costs while purchasing pvc joinery and also ensure to obtain higher performance from the pvc window in the future.
Glass unit types are generally classified as follows in terms of the purpose of use.
2.1. Heat Controlled Glasses (double glazing synergy)
Heat controlled glasses are the glasses of which insulation values are increased through Low-E coated ones. They keep the heat inside and prevent heat losses in the winter months. When compared to the standard double glazing glasses, they provide 50% higher insulation. Even as heat controlled glasses ensure to benefit from the solar heat to a maximum extent, they do not compromise on sunlight and transparency. These glasses are required to be preferred in the regions where winter months are severe. If this type of glass is preferred in the regions where winters are not severe, but summers are pretty hot, it will lead to the high insulation cost unnecessarily. Double glazing comfort is the glass which prevents hot weather from transmitting to the external environment in case of heat control. These are not the glasses which prevent the effect of the heat from sunlight.
2.2. Heat and Sun Controlled Glasses (double glazing comfort)
There is Solar Low-E coating on these glasses. Thus, cold weather entering inside in the winter is prevented by 50% and solar heat in the summer is prevented from entering internal environment by 40% and heating of the internal environment is avoided. These glasses are required to be preferred in the regions where summer months are pretty hot. If this type of glass is preferred in the region where summer months are not rather hot, but winter months are severe, it will prevent heating effect of the sunlight both in summer months and also winter months.
2.3 Laminated Glasses
Laminated glasses are manufactured by integration of double or more panes of glass under heat and pressure through private connector polyvinyl butyral (PVB). They minimize the risks due to the glass breakages by retaining the parts in position during breakage. Laminated glasses which are more durable against external impacts prevent or retard entries based on the thickness of the coating and the glass in case of theft and attack attempts by instruments such as rock and stick. Laminated glasses are also used in acoustic insulation. It is the glass group which has high sound insulation. As it has a feature to prevent UV rays from entering into internal environment by 97%, it also prevents furniture and fabrics from fading with the effect of sunlight.
Consequently, points to be taken into consideration in reference to the glass type when choosing pvc window can be listed as follows:
- 1. Thickness of the glass unit (double glazing or triple glazing)
- 2. Interstitial space distance between two glasses (the more interstitial space, the better the insulation)
- 3. Filling type to be used in the interstitial space (Air filled or Argon gas filled, insulation of the argon gas is higher) Cost-benefit criteria are required to be evaluated.
- 4. Double glazing synergy products should be preferred if the winter months are severe and summer months are mild and double glazing comfort products should be preferred if summer months are extremely hot and winter months are mild.
- 5. Laminated glasses should be preferred at places where security for theft and attack is high and glass and coating thickness should be determined with regard to security level while choosing these glasses.
- 6. Laminated glasses should be preferred if sound insulation is demanded to be high, but products with a favorable coating method for sound insulation should be preferred.
- It is required to consider that criteria such as glass feature, accessory, pvc profile series, pvc profile prices, thickness of the reinforcement sheet to be used also affect the PVC joinery prices.