What does Argon do for a window ?

Argon Gas increases the window’s ability to insulate. Because Argon Gas does not conduct heat readily as air, it helps keep heat in during the winter and out in the summer.

What does this gas look like ? Will I see it in my windows ?

No, Argon Gas is clear, colourless and odourless. Even if installed side by side you cannot see the difference between a window filled with gas and one not filled with gas just by looking at them.

How long will the gas stay in the window ?

Numerous studies show that gas typically leaks out less than 1% per year. Over twenty years the window still has 80% of the gas still trapped inside it.

Is Argon gas dangerous ?

An emphatic No ! - Argon Gas exists naturally in the air you breathe. It is both non toxic and inert.

Will my house plants grow ?

Argon does not block any portion of the suns light. Your house plants will not be affected.

Is it only for energy savings ?

Whilst energy savings are important, the real “comfort” benefit of gas filling is the increase in the inner glazing temperature. Raising the inner glass temperature climinates or substantially reduces condensation on the glass. A “warmer” surface is also more comfortable to be near.

Do all windows have Argon gas ?

Unfortunately not, gas filled windows are manufactured using specialised equipment and not all manufacturers have these facilities, so when buying new windows, make sure your window supplier can offer you the benefits of Argon Gas for that extra insulation.

Condensation - what causes it and how can it be prevented

Internal Condensation

Condensation on windows and in conservatories, and the damage it does to paintwork, curtains, wall coverings and window fittings are problems sometimes encountered in all types of buildings.

Modern aids to home comfort have created rooms which are warmer but which often have less ventilation and fewer air changes. The result is that the water vapour produced by normal living activities is no longer able to escape up the chimney or through door jambs, window joints and other outlets.

In certain circumstances, all these aids to comfort combine to create ideal conditions for the formation of condensation, which could form on the coldest surface within the room. This may not necessarily be on the glazing.

The question is how to reduce condensation without sacrificing the benefit of increased comfort.

External Condensation

Due to recent innovations in the efficiency of double and triple glazing, along with updated requirements of building regulations and the lowering of carbon emissions, certain weather conditions may allow the formation of external condensation on energy efficient windows and doors. This is a natural phenomenon and a clear indication that the window or door is preventing heat loss from your house.

Technical Definition

Condensation is defined as the physical process by which a gas or vapour changes into a liquid. If the temperature of an object (eg grass, metal, glass) falls below what is known as the ‘Dew Point’ temperature for a given relative humidity of the surrounding air, water vapour from the atmosphere condenses into water droplets on it’s surface.

This ‘Dew Point’ varies according to the amount of water in the atmosphere and air temperature (known as relative humidity). In humid conditions condensation occurs at higher temperatures.

In cold conditions condensation occurs despite relatively low humidity.

With regard to windows and doors, it is the difference in temperature between the internal and external environment and the glass, that causes condensation to form.

The Issue, what this means to the householder

The air surrounding us in our homes always contains water vapour, which is invisible. A typical example is the steam cloud from a kettle, which rapidly becomes invisible it has in fact been absorbed into the atmosphere.

The warmer the air, the more water vapour it can hold - but there is a limit to the amount itcan hold for a given temperature. When that limit is reached, the air is said to be ‘saturated’.

When saturated air comes into contact with a surface which is at a lower temperature thanitself, the air is chilled at the point of contact and sheds its surplus water vapour on that surface - initially in the form of a mist and, if excessive, eventually in the form of droplets of moisture.

An example of this is when a person breathes onto a mirror: condensation occurs because the exhaled air is saturated and its temperature is higher than that of the mirror (which is at room temperature).

What is Condensation

Breathing: Two sleeping adults produce approximately 1 litre of moisture in 8 hours, which is absorbed as water vapour into the atmosphere.

Cooking: Steam clouds can be seen near saucepans and kettles, and then seem to disappear. The clouds have been absorbed into the atmosphere. The heat source itself may be a source of water vapour, eg. an average gas cooker could produce approximately 1 litre of moisture per hour.

Washing Up: The vapour clouds given off by the hot water are rapidly absorbed into the atmosphere.

Bathing, laundry and wet outer clothing: These are often the major sources of water vapour in the home.

Heaters: A flueless gas heater can produce up to 350cc of moisture per hour. Paraffin heaters produce 4 litres of moisture for every 3.5 litres of fuel burned.

Indoor Plants: A frequently unrecognised but nevertheless significant source of water vapour.

New Property: The bricks, timber, concrete and other materials in an average three bedroom house absorb about 7000 litres of water during construction. Much of this is dissipated into the indoor atmosphere during the drying out period.

The factors governing condensation

1- Water vapour content of the air - This is produced by normal living activities such as washing, cooking, bathing, etc and can be controlled by the use of extractor fans, cowlings and ventilation at appropriate places.

2 - Inside room temperature - This can be controlled to some extent by replacing single glazing with double glazing, thereby maintaining a higher surface temperature of the glass on the room side, and by increasing the air temperature to enable it to hold more water vapour without condensing.

3 - Outside temperature - This cannot be controlled, but its effect on the inside room temperature can be countered by the installation of double or triple glazing.

4 - Internal and external temperature variation - This cannot be controlled as the mainvariant is the outside temperature. However, this variation may also be affected by building orientation, localised atmospheric conditions, shelter from nearby trees or buildings, air currents, wind speeds and nearby vegetation.

NOTE: It is often the case that external condensation will appear on some windows but not on others due to variable micro-climates in differing locations.

When attempting to reduce the degree of condensation it is important to note on which surface of the glass it forms; its location indicates the cause, and so points to the solution.

Internally - Condensation on the room side surface of the inner glass means that the temperature of the glass surface is too low given the water vapour content of the atmosphere in the room. This is most likely to occur on the surface of single glazed windows but can happen on double or triple glazed windows if the room isn’t heated.

Within the Cavity - Condensation within the cavity of an hermetically sealed double glazed unit or Insulating Glass Unit (IGU) denotes a failure of the seal.

Where the double glazing is achieved by the installation of secondary glazing, condensation on the cavity surface of the outer glass generally (but not invariably) indicates leakage of moist air from the room into the cavity. However the reader should note that it is not possible to hermetically seal secondary windows, therefore some migration of air from the room into the cavity is to be expected. Condensation can occur occasionally on the cavity surface of the inner glass when the sun in shining on the window. This means that something in the air space itself, such as an unsealed wooden separator or desiccant contains moisture. It should be noted however that this source can also be responsible for condensation on the cavity surface of the outer glass.

Externally - Condensation forms on the outside surface of glass when its temperature drops below the outdoor dew point temperature.

Windows manufactured with a double or triple glazed unit containing energy efficient low-emissivity glass have enhanced thermal insulation properties thanks to a high performance transparent coating that reflects heat from radiators or fires back into the room.

As a result the outer pane of glass does not get warmed by heat escaping from inside the building though the glass and remains cooler in comparison to less thermally efficient windows.

External condensation only occurs in certain climatic conditions - a variable combination of high relative humidity and clear cold conditions normally experienced in spring and autumn.

The new generation of thermally efficient double and triple glazed windows allow little or no heat through to warm up the outer pane. This creates the condition which allows condensation to form on the outside surface of the outer pane under certain weather conditions. This is strong evidence that heat is not escaping through the window.

The location of Condensation in the glass

It is important to remove excess moisture by ventilating rooms.A room can be ventilated without making draughts or causing it to become cold. One way to do this is to open the window slightly or use a trickle vent if fitted. By opening windows or ventilating your home it may appear that you are losing some heat, but what you are actually doing is allowing warm moisture laden air to escape and permitting cool dry air to enter your home. Dry cool air is actually cheaper to heat than warm moist air.

When formed on the room side surface of the inner glass:

1 - Provide natural ventilation through an opening section of the window, through a proprietaryventilating unit, or through an airbrick.

2 - Where there is no open fire, or where existing flues have been blocked off (and cannot be unblocked), ensure that wall vents are fitted and kept clear.

3 - Open at least one window in each room for some part of the day to permit a change of air.

4 - Ensure ventilation of all rooms where gas or oil heaters are used.

NOTE: This is a statutory requirement which will be monitored by the heating engineer.

5 -Fix hoods over cookers and other equipment producing steam and ventilate them to the outside air.

6 - Ensure that bathrooms and kitchens are ventilated in accordance with the National Standards.

7 - Draught proof internal doors and keep them closed to prevent transfer of air with high water vapour content from the main moisture producing rooms - kitchens, bathrooms and drying rooms. It should be borne in mind that water vapour does not remain in the room where it is first generated, but tends to migrate all over the house because:

a - The air pressure in the original room may be higher than elsewhere, and so the moist air will beforced out into rooms with a lower pressure, and

b - Air movement will carry it through the house.

8 - Increase slightly the air temperature within the house.

9 - In cold weather, keep some form of heating on permanently in the house.

10 - Wherever practicable, fix radiators under windows to maintain the temperature of the inner glass at a reasonable level.

11 - Condensation can be caused by isolating the inner glass from the warm room air with heavycurtains when drawn. To allow free passage of warm air to the glass, position curtains 15cm to 20cm from the window and ensure there are sufficient gaps at the top and bottom to permit continuous circulation.

When formed on the outer surface :

As this is caused by external atmospheric conditions, little can be done to prevent this condition atcertain times of the year. In many cases the condensation is not present for long periods and the sun often warms the outer glass enough to evaporate the moisture. If you require its removal sooner than would naturally occur, the use of a squeegee is recommended.

NOTE: The presence of external condensation is an indication that the glazing is thermally efficient andshould not be considered detrimental. The more thermally efficient the glazing, the higher the likelihood of condensation.

When formed on the frame

There are circumstances which will allow condensation to form on the inner surface of the windowframe. This is more common on steel or aluminium frames. There are aluminium frames which can combat this by having a thermal break however; this is only effective if the window is fitted correctly into the opening.

How to reduce condensation

Internal Condensation

This is usually a ventilation problem and cannot be caused purely by the installation of double or triple glazing. By acting as a heat barrier and providing an inner pane which is considerably warmer than the outer pane, condensation may be reduced.

Modern buildings are designed to eliminate draughts and do not have the natural ventilation thatsome older houses have with their chimneys and ill-fitting windows and doors. Houses which have been completely sealed by the installation of cavity wall insulation, loft insulation, double or triple glazing, and draught proofing throughout are likely to become moisture traps. In such cases, condensation is a ventilation problem. Provided the rooms are heated normally, the solution will probably be found by providing controlled ventilation.

When a lack of ventilation is suspected, the householder should consult a heating and ventilation engineer.

In the case of the older, ‘unsealed’ buildings, the dominant factor is likely to be the indoor temperature, and additional heat, or the introduction of localised heat near the windows will probably provide the answer.

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Natural oxidation of leaded windows

Like any natural lead product exposed to the environment, lead profile will undergo certain ‘atmospheric’ transformation. This is perfectly natural and it will eventually settle down to take on the traditional ‘weathered lead’ appearance that is so admired in old churches and the leaded windows of stately houses. During this process however, especially in the early stages, some people may become concerned at the changes they see occurring.

Why do changes occur ?

Lead profiles from our supplier RegaLead are made from refined, almost pure lead and, although this has been alloyed to improve performance, when it is exposed to the atmosphere for the first time it becomes subject to a process called oxidation.

Chemists define the process of oxidation on lead as: “a chemical reaction instigated by the exposure of lead to the atmosphere in which insoluble lead compounds such as lead sulphate (PbSO), lead sulphide (PbS) or lead oxides are formed on the surface. These major reaction products naturally form a compact, non-porous adherent film on the lead’s surface which stilifies further reaction between the metal and the atmosphere”

Put in more simple terms it means that when lead profile first comes into contact with the atmosphere, the surface gradually oxidises to form a natural protective film called a patina, and it is this which eventually produces the familiar grey colour.

What changes are seen ?

During the initial stages of patination the lead can appear to take on various colours such as blue, bronze, gold and green. This effect is purely optical and is usually due to the angle of light. The effect is similar to the colours seen when oil is spilled onto a wet road surface. Gradually, however, these colours will fade away to eventually leave the final protective grey patina.

There is another side-effect of oxidation which can occasionally give rise to concern. When lead first comes into contact with moisture (rainwater or condensation) it may result in temporary discolouration, spotting and even the appearance of white powdery deposits (basic lead carbonate) which in wet weather can run onto the glass. Again this is perfectly natural and the temporary blemishes will eventually disappear as the patination process continues.

The powder can safely be wiped off from time to time until the natural patination process if fully eveloped.

Treatment

There is no need to treat the lead profile as the patination process will occur naturally.

The process can be controlled however, by applying Patination Oil which will encourage the formation of the grey patination finish. It is important that this is applied as soon as the lead profile is installed, as once natural patination process has started and spotting occurs it is too late.

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Recycling post consumer uPVC

SETRADE are committed to recycling

Recycling uPVC is not only ethically and environmentally rewarding, it also makes good financial sense. It eliminates the substantial cost of landfill whilst helping to attract customers with a green conscience. As environmental concerns become more and more prominent in the global media, homeowners increasingly seek out companies with enviable environmental credentials.

Considering that every uPVC window can be recycled around ten times, there is absolutely no reason why this valuable resource should be added to our already overstretched landfill. If windows have an average lifespan of around 35 years, we have potentially 350 years-worth of good PVC material to use. Recycling uPVC drastically cuts down depletion of the world’s valuable resources and subsequently, the eco-friendly recycled windows we sell demonstrate a positive environmental commitment.

Our aim is to help prevent recyclable material being lost to landfill. We have a dedicated area, where the old uPVC frames are deglazed and prepared for processing. As part of our service at SETRADE we will accept our customers waste uPVC frames free of charge.

For more information, please contact us at SETRADE (01323) 847234

Pilkingtons launch 2 new textured obscure glass patterns

New textured designs from Pilkingtons

New products, Pilkington Cassini and Pilkington Tribal, add to the manufacturer’s existing texture glass range, which helps homeowners maintain privacy and security while adding style to windows and doors, partitions, dividers, splash-backs and cupboards.

Pilkington Cassini features fine line detail that offers a multi-layered effect, resulting in a modern design influenced by the mosaics of Barcelona. It’s achieved by engraving the roller, which marks the pattern onto the glass during the manufacturing process, using cutting-edge technology. 

In contrast, Pilkington Tribal has a hand-drawn finish inspired by Aztec patterns. To achieve this look, Pilkington used traditional hand-engraving methods when creating the roller to produce a modern patterned glass that’s steeped in history.

These patterns are readily available now, at standard leadtimes. Samples of all the Pilington obscure patterns are displayed in our showroom at SETRADE Unit 6, Burfield Park Industrial Estate, Hailsham. Pop by and have a look

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Slimline Heritage units increase in demand

Timber window refurbishment on the increase

During the past 6 months we have noticed an increase in demand for 12mm slimline double glazed glass unit. (4mm glass / 4mm spacer bar / 4mm glass). The combination of the heritage aesthetics and improved thermal performance the slimline unit a great option for timber refurbishment and joiners alike.

The thermal and acoustic performance of the glass can improve any Conservation area project, making it a great choice. The units glass edge sight lines are narrow, so can be accommodated by most timber window rebates, the product carries a 5 year guarantee

Call us at SETRADE 01323 847234 for more information

www.setrade.co.uk

www.vertislide.co.uk

Pane in the glass...what goes into making sheet glass

Glass, do we take it for granted ?

Glass do we take for granted ? Probably, but do you know what goes into making sheet glass. I had the opportunity to visit a glass plant in Belgium a few years ago, I seriously had no idea what went into producing glass for the construction industry. Hopefully this will give you a bit of an insight.

Its understood the Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt. ... In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century. That's the history.

But what is glass made from ? Believe it or not, glass is made from liquid sand. You can make glass by heating ordinary sand (which is mostly made of silicon dioxide) until it melts and turns into a liquid. You won't find that happening on your local beach: sand melts at the incredibly high temperature of 1700°C (3090°F).

So what’s the process of making sheets of glass (float glass) ? The phrase “to float” means “to be buoyant”. And this is basically the principle on which the float glass manufacturing process is based. In the float glass process, molten glass is fed onto a float bath of molten tin. This tin bath is 4-8 meters wide and up to 60 meters long. To prevent the tin surface from oxidizing with the atmospheric oxygen, the tin bath is placed under a protective gas atmosphere. This atmosphere must be carefully controlled since its composition is instrumental for the properties of the contact surface between the glass and the tin which, in turn, influence the thickness of the glass sheet. 4mm and 6mm glass thicknesses are used in standard glazing, with thicknesses of 8mm and 10mm being used for commercial applications.

The glass floats like an endless ribbon on the tin. At the entrance where the glass first makes contact with the tin surface, the temperature of the liquid metal is about 600oC. Tin is the only metal that remains in a liquid state at 600oC.

Immediately after the exit from the float chamber, special rollers take up the glass and feed it into the annealing lehr from which it exits at about 200oC. After cooling to room temperature on an open roller track, it is cut, packed, and stored ready for shipment.

The factory I visited in Belgium had 2 glass plants, with massive furnaces and runout processing beds disappearing off into the distance. Each plant was run for 24 hours a day, 7 days a week, continuously for 7 years (the life of the plant). The refurbishment of the plants are offset, to enable a continuous production glass to be maintained. When the refurbishment time comes, it takes 3 months to clear the plant of material and for the furnace to cool. The furnace is broken down, and totally rebuilt, the line is pretty much replaced. As technology is constantly this can be incorporated into the new plant at the time of the refurbishment (it takes approximately 12 months to rebuild the plant). Once complete the plant is fired up, from this point it takes an additional 3 months before glass of the correct quality and specification comes off the line and into the industry.

The process is detailed as follows :-

1. Batching of raw materials: The main components, namely, soda lime glass, silica sand (73%), calcium oxide (9%), soda (13%) and magnesium (4%), are weighed and mixed into batches to which recycled glass (cullet) is added. The use of ‘cullet’ reduces the consumption of natural gas. The materials are tested and stored for later mixing under computerised control.

2. Melting of raw materials in the furnace: The batched raw materials pass from a mixing silo to a five-chambered furnace where they become molten at a temperature of approximately 1500°C.

3. Drawing the molten glass onto the tin bath: The molten glass is "floated" onto a bath of molten tin at a temperature of about 1000°C. It forms a ribbon with a working width of 3210mm which is normally between 3 and 25mm thick. The glass which is highly viscous and the tin which is very fluid do not mix and the contact surface between these two materials is perfectly flat.

4. Cooling of the molten glass in the annealing lehr: On leaving the bath of molten tin, the glass - now at a temperature of 600°C - has cooled down sufficiently to pass to an annealing chamber called a lehr. The glass is now hard enough to pass over rollers and is annealed, which modifies the internal stresses enabling it to be cut and worked in a predictable way and ensuring flatness of the glass. As both surfaces are fire finished, they need no grinding or polishing.  

5. Quality checks, automatic cutting, and storage: After cooling, the glass undergoes rigorous quality checks and is washed. It is then cut into sheets of sizes of up to 6000mm x 3210mm which are in turn stacked, stored and ready for transport. These massive sheets of glass are know as ‘Jumbos’.

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