Glass should normally be cleaned with a clean cloth and a clear non-abrasive cleaner such as clean soapy water or a proprietary window cleaner. For glass with a patterned or sandblasted surface, a stiff bristle or nylon brush can be used to remove dirt from the recesses in the surface.

If the glass does not become clean using the above methods the following can be tried:

Use a mild acid says vinegar or a mild solvent says methylated spirit, taking care not to spill any of these on other surfaces or materials.

If neither treatment works then the glass will need to be abraded and re-polished. This is likely to be expensive and should be left to experts. The process may result in some optical distortion where the glass surface has been removed.

Things to watch:

1. Organic solvent cleaners should be avoided on mirrors since they may attack the backing paint.
    
2. Leaded Glass should only be cleaned with a clear non-abrasive cleaner. The cleaner should be of a type that does not remove the patina (aged surface finish) of the lead.
    
3. Patterned glass and sandblasted glass should only be cleaned with a clear non-abrasive cleaner. Any insolublematerial in the cleaner may deposit in the recesses of the etching or sandblasting and may be very difficult to remove.

Condensation forms when moisture laden air meets a cold surface where the surface temperature is at or below the dew point. At the dew point moisture will condense from the air. Warm air will hold more moisture than cold air. Keeping the air temperature up changes the dew point and keeping the humidity down.

Ventilation helps to keep the humidity down and fitting low e glass raises the internal glass temperature so condensation is less likely to occur. Low e glass also reduces the outer pane temperature which can lead to external condensation on the glass. External condensation is less of a problem for windows and can be seen as evidence that the glass is providing thermal benefit.

Low E, or simply known as low-emissivity, glass was created to minimize the amount of infrared and ultraviolet light that comes through your glass, without minimizing the amount of light that enters your home. Low E glass has a microscopically thin coating that is transparent and reflects heat. The coating is even thinner than human hair. The Low E coatings keep the temperature in your home consistent by reflecting the interior temperatures back inside.

Types of Low E Coatings:

Passive Low E Coatings (Hard-Coat): The passive Low E coatings are manufactured using the pyrolytic process, which creates a pyrolytic coating. The coating is then applied to the glass ribbon while it is being produced on the float line, which causes the coating to “fuse” to the hot glass surface. This fusion creates a strong bond, or “hard-coat,” that is very durable.

Solar Control Low E Coatings (Soft-Coat): Solar control Low-E coatings are manufactured using the Magnetron Sputtering Vapor Deposition (MSVD) process, which means the coating is applied off-line to pre-cut glass in a vacuum chamber at room temperature. This coating, which is also referred to as “soft-coat,” needs to be sealed in an insulated glass (IG) or laminated unit. The soft-coat has lower emissivity and superior solar control performance. This coating offers the highest performing solar control.

Before you decide between hard coat or soft coating low E coating glass, it is important to consider your area’s climate:

If you live in an extremely cold climate, the hard-coat Low E glass may be an option for you, because it allows some of the sun’s short-wave infrared energy to pass through the glass. This helps to heat your home in the winter and allows the glass to reflect the interior long-wave heat energy back inside.

However, if you live in a cold to hot climate, which covers nearly all of the United States, the soft-coat Low E glass is best, since it offers better UV protection and has a better overall U value. The soft-coat Low-E coating also reflects the warm and cool air back into your room instead of allowing it to leak outside.

The U Value is a measure of air to air heat transmission (loss or gain) due to the thermal conductance of the material and difference of indoor and outdoor temperature. It is used to compare the insulation of glass products worldwide and its units are watts per square metre per degree Celsius or Kelvin (K) (W/m2°C). The lower the U Value the better the insulation of the glass or glazing system. The U Value is the reciprocal of the R Value and either can be calculated from the other (i.e. U=1/R or R=1/U).