Designing Air seems a strange term – yet that is exactly what I am trying to do. The ideal air is constantly the right temperature, the right humidity and free from contaminants. A comfortable air for a home requires a co-ordingated balance between:
- Thermal Mass
- Heating and Cooling
- Ventilation and Condensation Control
Thermal mass is the ability of your homes construction materials, exposed to the sun, to warm and release warmth. Concrete is the best thermal mass, wood the worst. Using concrete walls or floors exposed to sunlight means your house will both overheat less in summer and keep warm during winter, Wood heats up quickly and loses heat quickly – consider it a bit like your Glycemic Index for food. You don’t want the equivalent of sugars that give you a quick energy hit then drain you later. You want high glycemic index foods that are slow to release their energy and release it longer and in a more constant rate. Your house thermal mass works in a similar way.
Heating and Cooling
Heating systems vary significantly between countries. In Northern Hemispheres a central boiler system is most prevalent for heating; whereas these are not used in the Southern Hemisphere, relying more on wood burners, flued gas fires, heat pumps and electric heating.
Cooling systems are either heat pumps or fully ducted air conditioning systems that provide ventilation, condensation control, heating and cooling.
Ventilation And Condensation Control
The popular ceiling cavity ventilation systems rely on having sufficient cavity space to trap air heated by the sun during the day to be cycled through the home at night. Personally, I don’t like the idea of air full of insulation fibres, dust and mold coming in to my home – regardless how good they maintain their filters are. In saying this, filters vary greatly by product and there are some that now offer hospital equivalent filtering.
The building standards generally give the absolute minimum required for floor, wall and ceiling insulation. Studies have shown that increasing the specification to the next product level will signifiantly decrease the amount of energy needed to heat and cool the home – since the installation fee is the same, the savings are far more than the additional product cost.
Over the next week I will be investigating each of these more closely for my project home.