Macau lies in the subtropical climatic zone as indicated in figure 12. As a result is characterized by hot summers and mild winters. The passive strategies used by these vernacular designers for this particular area was focused on the hot season. The Watson&Lab in figure 1 illustrate the strategies adopted by the local builders to guarantee the comfort zone in the dwellings.
CONDUCTION
The conduction heat transfer basically is a based on the temperature gradient of the area, the cross of the material, the length of the travel path and the physical material properties.
Reduce heat gain
Since Macau has a tropical climate the walls were constructed of mud which had a high thermal capacity to store heat during the day and give it out to the internal environment during the night. Also they adopted the use of brightly coloured plaster to offset the solar intensity.
Increase Heat loss
The Tulou and the Huizhou were characterized by higher ceilings and roof opening that allow the heat gain whether internally generated or stored by the internal mass from external gains to loose their intensities to the external environment . The postulate of thermodynamic states that heat flows from a higher kinetic energy zone to a lower kinetic energy zone. With this analogy the heat in these primitive dwellings were dispensed off to the surrounding soil by lowering the floor of these ancient structures .
VENTILATION
Ventilation is the introduction of ambient air into a space either naturally or artificially. For primitive design where artificial ventilation was unknown, the ambient air affected to a higher extent character of air that circulates.
Reduce heat gain
To reduce hot air circulation enclosed construction types were adopted in the Siheyuan, Tulou and the Huizhou dwellings. Also these structures were constructed close to water bodies, had central pools which were able to cool down the ambient air as it moved towards the dwellings. For example the Huizhou Moon pool, and the Tianjing.
Increase Heat loss
These structures incorporated wind towers to extract hot used air and replace with fresh cold air through the buoyancy effect.
RADIATION
Radiation is when the electromagnetic waves that travels through space transfer heat into an object on impact. This parameters is very significant in any building that strives for energy efficiency
Reduce heat gain
The overhangs and the deep verandas were used to prevent most of the direct incident radiation from entering the occupant spaces. Lighter coating such as plaster mud were also adopted to offset a higher percentage of these solar gains
Increase Heat loss
The opening spaces such as the court yards served as a sink for energy gains .The surrounding soil, larger windows and the central pools helped to increase the heat loss of these primitive structures.