Human comfort and low energy systems in buildings are not necessarily a contradiction in terms, in fact it is a paradox that low energy systems more often than not provide better comfort. It is also a paradox that in buildings in cities throughout the world, even in temperate climates, that vapour compression equipment is providing cooling throughout the year even though the external temperature for the vast majority of time is lower than the internal building ambient temperature.

via Alternative Cooling and Low Energy Systems – Ambthair Feature.

The quote above is from a very useful document discussing the practical methods of reducing heat gains in building with an eye on energy saving and occupant comfort.

Another useful source of information is the WBDG (Whole Building Design Guide)