If insulation applied is faulty or insufficient, the exposed surfaces in a room will stay significantly colder in winter or hotter in summer than the room temperature. Although the heater pumps hot air into a room, or the air-conditioning blows cool air, the thermal radiation will affect the equilibrium. The Mean Radiant Temperature is affected negatively and the occupants won’t feel comfortable.
- The ceiling isn’t insulated or the insulation is penetrated for example because of the installation of down light. As warm air is always moving upwards, heat is lost to the cooler air in the roof space.
- Air leakage around doors, windows, down lights, pipes, and other wall penetrations are exceeding the acceptable Relative Air Velocity.
- Wrong application of thermal mass can influence the Mean Radiant Temperature and can therefore increase the need of mechanic heating and cooling.
- Under- performing windows and doors (when air is able to leak in/out of poor fitting doors and windows) are also influencing the Mean Radiant Temperature and the Relative Air Velocity.
When it comes to comfort, the perception of temperature is more important than the temperature itself.
For a person to feel comfortable, the difference of temperature between the head and the feet should not exceed 2.5 degrees. This demonstrates the importance of floor insulation and this explains why we usually feel more comfortable standing barefoot on carpet than on tiles.
Unfortunately the energy rating system in Australia doesn’t really take thermal comfort into consideration. The Passive House standard on the other hand looks at thermal comfort closely and makes sure that you will always feel comfortable inside your house, no matter how cold or hot it is outside.
Want to know more about passive house? Please feel free to get in touch.
Do you want to know more about the basics of Thermal Comfort, please have a read through our article What is Thermal Comfort?