| CRITERIA |
ALUMINUM |
PVC |
REMARKS |
| HEAT INSULATION |
The Thermal Conductivity of Aluminum is 175 Kcal/m2-hr-*C. This means that aluminum has the capability to admit heat at a rate of 175 Kcal/hr.
Thermal break system is an alternative for Aluminum to improve its heat insulation property. However, the profile section of the windows will be less rigid due to PVC inserts and the profile are coming into 2 sections. The structural integrity of the aluminum profile is compromised because the thermal break element is not as structurally sound as the aluminum it is replacing sectionally. Also, this process results into extra cost. |
The Thermal Conductivity of uPVC is 0.14 Kcal/m2-hr-*C. This means that is can absorb heat at a rate 0.14 Kcal/ hr only. uPVC window system is coming into one full section having its materials as an inherent heat insulator. |
The lower the Thermal Conductivity signifies lower ability to absorb and transfer heat. uPVC Windows is better by 1250 times than aluminum.
The profile section of uPVC is coming into one piece only and not two compared with thermally break aluminum. |
| SOUND INSULATION |
The Aluminum material is a good transmitter of sound due to its material natural property. There is less chambers in the profiles section due to its complexity in extrusion for thin members. The sound insulation values of Aluminum windows with 6mm single glass is 13-16 decibels while with a double glass can achieved 22-24 decibels. |
The uPVC window system is a good sound insulator due to the inherent property of PVC plastic material. There are 3-6 chambers section in uPVC windows which makes it a better sound insulator, allowing more space for sound to travel. The sound insulation value of uPVC windows with 6mm single glass is 22-25 decibels while with a double glass can achieved more than 30 decibels. |
Sound travel through a medium. The more void space, the better will be the sound insulation. uPVC has the flexibility of extruding with thin walls , thus allowing more chambers or void areas in the system. This makes the uPVC Window system a better sound insulator. There is a better advantage in terms of sound insulation for complete windows with uPVC system. |
CORROSION
RESISTANCE |
Aluminum in its natural state is highly reactive to corrosion cause by water, humidity, acids , alkalis and other industrial and commercial chemicals. However, aluminum manufacturers have improved the aluminum corrosion resistance by anodizing or powder coating. This does not guarantee that it will not corrode. Due to continuous exposure to environmental factors and also because of its inherent high thermal conduction property, aluminum can cause condensation build-up in the interior of the home which may cause condensation and damages the window surface, interior fabrics, wall papers and wood surfaces. |
uPVC material is by itself has an excellent resistance against water, humidity, acids, alkalis and other industrial and commercial chemicals. This is the reason why such material is being used as containers for many hygienic and aggressive chemicals like acids. Condensation is very minimal and before it affect the interior it usually evaporates. |
uPVC has its inherent physical property to be resistant against corrosion and there is no need for coating application to protect itself. The powder coating or anodizing of aluminum when remove due to exposure to external factors will result in corrosion of the peeled off areas. Nicking and feeling off of coating is not applicable with uPVC as compared with aluminum which is artificially coated. |
CORNER JOINTS
INSULATION
AND STRENGTH |
Fabrication of Aluminum windows are done by using mechanical fastening of the corner joints making it to the least hair line gap between two aluminum profile section. |
uPVC window system uses the Butt fusion welding system which makes the jointing to be of one piece. Thus, there is no gap between the two profile sections of the windows. The results is a watertight system. |
The joint between two profiles section of the windows is one area where sound, dust and foreign material could enter into the system. Although aluminum have improved to make the gap almost to a hair line but to its big contraction and expansion as attributed to its thermal conductivity, the joints will move after sometime making the gap bigger than a hairline. This will then allow the sound, dust, rain, water and other foreign material to come. Unlike with uPVC having a one welded piece , the system does not allow the enrty of sound, dust, rain, water , etc. Butt fusion jointing is stronger compared to mechanically screwed joints. |
| IMPACT RESISTANCE |
Aluminum has a good impact resistance but its resistance is basically dependent on the profile thickness. |
uPVC windows has an impact resistance of 30 KJoule/m2. Profile section is tested by dropping a 1 kilo tap from a one meter height at a temperature of -10 degrees centigrade and no breakage or damage should be observed. uPVC Window being a polymer material has a natural tendency to let bounce any materials drop into it. It has the natural resiliency property which makes it a good material against impact. |
uPVC can attain the Impact resistance required as per its used as Windows. |
| ENERGY SAVING |
Aluminum being a good conductor of heat can contribute into the quick heating the house or room interior. |
uPVC being a naturally heat insulator material does not contribute into the heating of the house interior neither cooling during cold season. If used with a compatible high performance glass as panel filling, the uPVC window can result into a savings of 30% energy . |
uPVC Window system is an energy saving window system. |
ARCHITECTURAL
FLEXIBILITY |
Aluminum can be formed and shaped to different designs but it has certain limitations. As an example, arched windows need to be smooth and no flaws during bending. However, due to certain bending stress, arched windows have to be cut into sections on some areas of the profiles to achieve the desired degree of bends. |
uPVC profiles can easily be shaped and bended by heating making it more flexible. Thus can cater mostly required degree of bends. |
uPVC has more flexibility in architectural designing. |
| SAFETY FEATURES |
Aluminum starts to burn at a high temperature. During the burning, it produces toxic combustibles which is detrimental to human lives. The source of toxins were contributed mainly on the processing of aluminum like chromate for cleansing, acrylic and polyester enamels used to paint the aluminum and nickel aluminum to produce an anodized coating. All these are said to be toxic. |
uPVC burns at a rate 10% slower than the common materials inside the house like carpets, wall papers, drapes, silk and wool, wood, etc. Combustion gases are also toxic. uPVC is a self extinguishing material and does not support combustion or continuous burning. |
Both aluminium and uPVC when burning produce toxic gases during combustion. However, the rate of burning of both material is slower compared to wood and other interior components like carpets, silk, wool, fabric, wall papers, etc. Therefore uPVC and aluminum are considered to be a safe and acceptable construction materials for windows and doors products. |
ELECTRICAL
CONDUCTANCE
AND INSULATION |
Aluminum is one of the best electrical conductor. |
uPVC is non electrical conductor such that it is being used as wire and cables coating. |
The uPVC system is safer to use as windows, doors, skylights in terms of electrical conductance. |
| PRICE/COST |
Aluminum needs to be thermally break system for it to have a good insulation against heat. It has to be powder coated or anodized in order for it ot be corrosion resistant. Fixation on the corners needs to utilize proper fasteners like stainless screws in order for it to last longer. All the above means an added cost. |
uPVC has its natural heat resistance capability. uPVC has its natural surface to be corrosion resistant. The joint are butt fussion welded and does not required added fasteners which are costly. |
uPVC is said to be pricewise better or competitive compared with aluminum (with thermal break) having the same or equivalent performance with uPVC. |
