Drawbacks and Problems with Skylights

Do not neglect possible drawbacks when selecting skylights. Skylights aren’t only a source of light or natural ventilation and views. They may also be an unwanted source of heat losses or solar gains, infiltration and moisture.
 

Condensation

In cold weather conditions, many skylights are prone to water vapor condensing on their glazing, which may then drip into rooms.

But this problem can be avoided today. Well installed and efficient skylights are virtually immune to condensation problems. Better skylights may have interior channels to collect the condensation water, which can be evaporated later.

You just have to buy good energy-efficient skylights and have them properly installed.


Heat Loss Problems

Traditional skylights are susceptible to greater heat losses during cold weather than windows. To avoid this eventual problem, skylights should incorporate modern energy efficiency options, namely low-E glasses panes, filled with argon or other gas. 

Skylights made with plastics, and skylights with a dome and ridge design are typically energy inefficient, and cannot incorporate energy-efficient technologies. Avoid cheap skylights, and pay attention to their rating (via Energy Star or other equivalent labeling) to avoid heat loss problems.

Modern manufacturers use various technologies to reduce the heat loss and the inopportune solar heating associated with traditional skylights. These technologies include special glasses (double glazing and triple glassing and low-emissivity coatings) and heat-absorbing tints (see: Solar films).

 

Inopportune solar heating and UV ray damage

Skylights are typically highly exposed to hot sun, which may result in a high solar heat transmission at inopportune times.

Traditional skylights also transmit direct sunlight, with the potential UV ray damage to carpets or furniture.

A careful location of the skylight and a strategy involving trees and their shading, may help to alleviate this problem, in some cases. But there are many situations where the problem should be handled differently: selecting tubular skylights or selecting small traditional skylights (skylights have not to be large to driven large amounts of daylight) with low-E/spectrally selective glasses and low U-factor (low solar heat gain coefficients).

See:
The skylight size and installing
Skylights and selection



Infiltration

Natural ventilation is a major goal associated with traditional roof skylights. These skylights can be opened during warm periods, allowing the home’s warm air to rise toward them and escape, with the resulting cooling.

But the inverse may also happen. Traditional rectangular skylight surfaces can cool the air that rises to them, making rooms uncomfortable in cold climates and seasons.

Besides, improperly installed skylights are especially prone to air infiltration through spaces between their glazing and frames.  

The only way to avoid these possible drawbacks is once more high quality skylights, and a careful installation.

See:
The skylight size and installing
Skylights and selection




 




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