What are Double Glazed Doors
Double glazed doors are constructed with two glass panels that are separated by a spacer which is then filled with gas and sealed off. This ensures that the doors are airtight and none of the gas will escape. As there are different types of glass used in double glazed doors, choosing the right one for your house or office is important due to the climate where you reside.
Tinted glass is used as a design feature and also to reduce heat gain. This is useful in warm climates where the purpose is to keep the heat out of the house or office by reflecting solar energy. It is also used to keep out the glare from the sun and is normally placed on the exterior side of the door in order to absorb heat and re-radiate it.
Coated glass is used when you want to retain heat in your homes or office. This is energy efficient as you will spend less on electricity bills to keep the area warm. This is also useful for blocking out external sound especially if you reside in a busy and noisy area. It also keeps heat from entering your house.
Low emissivity glass has a thin metal coat on the glass. This allows heat and sunlight to enter your home but at the same time prevents heat from leaving. As with coated glass, this is also energy efficient. There are different kinds of low emissivity glass. High Solar Gain glass is used in climates that have cool summers and cold winters. It reduces heat loss and lets a moderate amount of heat into the home. Moderate Solar Gain glass is chosen normally for areas with mild summer and winter. This allows for a small amount of heat to enter. Low Solar Gain glass provides the greatest amount of protection from UV rays and is used in hot summer areas but with moderate winter.
You will also need to consider ventilation. Due to Double Glazed Doors being airtight, reduced ventilation will result in condensation. More Info at http://www.french-patiodoors.co.uk/conservatory-doors/
This can be solved with trickle vents incorporated into the door frame to let in a small amount of fresh air.