Solar Heat Gain Factor table for southern latitudes

[francismann]

TL;DR

SHGF tables provided by ASHRAE only includes north latitudes, the cooling load for the building I am designing for is in the south latitude.

Hello! Despite being a mechanical engineer I'm fairly new to building science. I'm looking to compute for solar heat gains in a building somewhere down south. ASHRAE SHGF tables only lists data for north latitudes and there's no mention of the south latitude. May I ask why there isn't any on the south and if there is, where can I find it? Many thanks!

 

[Filip Larsen]

I am not a building engineer or even a mechanical engineer, but if solar gain alone is about the heat gain from the influx of sun light over a period of time at a given latitude, then I would expect this gain to be equal for same latitude north and south, with the north and south direction swapped in case direction (azimuth) is relevant.

 

[Baluncore]

@francismann
Welcome to PF.

but if solar gain alone is about the heat gain from the influx of sun light over a period of time at a given latitude, then I would expect this gain to be equal for same latitude north and south, with the north and south direction swapped in case direction (azimuth) is relevant.

I would change the sign of the latitude to place it in the Northern Hemisphere, rotate the building aspect by 180°, and change the date to correct the seasons by adding or subtracting six months. The apparent path, followed by the Sun during the day, would be reversed about solar noon, since East is West, and West is East, and never the twain will meet. (Rudyard Kipling, misquoted).
https://en.wikipedia.org/wiki/The_Ballad_of_East_and_West

 

[Tom.G]

For Solar position see post: https://www.physicsforums.com/posts/6959658
From there, you calculate the angle of incidence on the surfaces to determine the insolation energy on each surface.

Depending on your requirements, you may want to account for the additional insolation loss by the longer air path at low Sun angles.

You will also need cloud cover statistics (often available on a regional basis).

Outdoor temperature records were generally available for locations near enough to be useful in calculating conductive heat gain/loss; this was calculated hourly for one day in each month of a year, and multiplied by days in each month for monthly subtotals.

If I recall correctly, the hourly outdoor temperatures had to be estimated/interpolated. The daytime temperature curve roughly resembled a sine wave with the peak around mid afternoon. The nighttime temperature is mostly a straight line drifting down to the daily low shortly before Sunrise.

Cheers,
Tom

(Irrelevant note: This was done to meet the energy efficiency requirements in the California Building Code [Title 24] for residential, commercial, and industrial buildings.)