Direct gain solar houses: design guidelines for Wellington

Abstract

With the recent oil shocks and price rises, the sun is being regarded as an alternative form of energy. This energy source has always been present, but for a long time, its benefits were disregarded in favour of the built environment being controlled by man-made systems. Extensive research has been undertaken recently to rediscover the solar heating principles used by earlier cultures, but abandoned by 'Modern Man'. Most of this research has been carried out in 'ideal' conditions, ie on a horizontal site with an unobstructed view towards the equator (the direction from which the sun's rays strike the building). The idea for this report came about through the question I asked myself: How effective is the sun's energy in heating a house if the conditions are not 'ideal', with special regard to Wellington's hilly terrain, where sites are often both sloped, and not always able to face the equator (sometimes even facing the pole)? This report presents the results of simulations (that predict the heating requirements of the house, in order that it remains above a predefined temperature) of a defined standard building that is modelled and then subjected to a year of weather data. Design parameters, such as the direction the building is facing, are varied in order that the effect of these parameters upon the heating requirements of the house (as generated by the computer program SERIRES) can be observed. From these simulations, a set of guidelines for the design of direct gain solar houses in Wellington are developed, and presented in easily accessible form.