PH Envelope T/F

What factors affect the perception of thermal comfort by humans in building interiors?

Air Velocity

True

Humans are very sensitive to drafts

Exterior air temperature and relative humidity

True

In winter, in cold climates, the external air can be cold and very dry, despite it having a high ‘relative’ humidity. If you over-ventilate in such conditions, you can end up drying the internal air in a Passive House (unless you have a humidifier). In such climates, an ‘ERV’ is better than an ‘MVHR’  because the former can allow some moisture migration from the moist internal air to the dry external air. 

Thermal equilibrium of the human body

True

 If the body is not in thermal equilibrium it will likely experience discomfort

Degree of natural day lighting

False

Whilst we appreciate and benefit from natural daylight, it does not affect thermal comfort.

Color of Clothing

False

This has no influence on our thermal comfort

Air Pressure

False

This has no influence on our thermal comfort

Levels of Carbon Dioxide

False

This has no influence on our thermal comfort, although it is an excellent indicator of indoor air quality

Type of filter used for supply air

False

Filter type can have an influence on indoor air quality (concentration of particles for example) but does not influence thermal comfort

U-value of Glass

True

This can have a strong influence on human comfort, especially with glass of poor performance which will radiate cold into the interior space when the exterior temperature is low

Thermal bridges

True

Thermal bridges typically result in lowering the surface temperature at poorly insulated junctions which in turn adversely affects comfort levels