Skylights

Skylights can provide daylighting, but can also lose a lot of heat in the winter and bring in a lot of heat load in the summer. A skylight mounted flat allows in three times as much energy in June when the sun is high than it does in December (at least at 40 deg N latitude). This can create excessive cooling loads. You need to install them in a purposeful way so that the benefits of daylighting are more than offsetting the heat losses you mentioned and the extra heat gains in the summer.

Thanks & Adios,
CJD ----

Carol J. Dollard, P.E., LEED AP
Energy Engineer
[email protected]

Hi,

This puts me in mind of celestory windows, which have something in common with skylights but angled vertically so they take advantage of the winter sun. Suitable eaves ensure that the summer sun is excluded. Here at 35 degrees South they can be incorporated into an energy efficient roof design whereby the roof is tilted South (minimising penetration by summer heat) and a row of North-facing celestory windows collect winter sun. Our local university's Innovation campus sports a number of buildings like this, recently constructed, but with all the celestory windows pointing SOUTH. Needless to say, their roofs are angled to absorb heat from the sun in summer, with no winter sun entering those high windows. We can only wonder.

Lorna 

Hi -

We're in tropical northern Australia and skylights are a huge heat sink at almost any time of the year. Solartubes are better in two ways - almost no heat ingress and some flexibility in positioning the internal light source in ways that skylights simply can't do. However, best of all are the optic-fibre sky-light systems which have the flexibility to deliver natural light far deeper into a building than solar-tubes. Check these websites. http://www.skydome.com.au/products_parans_home.htm http://www.dayray.com.au/index.cfm?page=technology

regards
Lisha K.

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