Unit 1: Condensation Flashcards
When and how does condensation occur?
- Condensation occurs mainly during cold whether
- It forms when warm moist air and steam are produced and the warm air comes into contact with, and condenses in, a cold surface before it can leave the building
- Condensation is caused when water vapour comes into contact with surfaces below dew point.
Where does condensation commonly occur
- In corners, or near windows, behind wardrobes and cupboards
- It often occurs on north facing walls
What are sources of water vapour
- Breathing, cooking, washing, drying
Constructional defects: penetrating damp, rising damp and leaks
What is Dew point and when does it occur
- The dew point is the temperature at which the air is saturated with water vapour
- if a surface cools below the dew point, water condenses on the surface and dew drops are formed.
- Surfaces cool strongly at night
What happens when warm air comes into contact with a surface below dew point ?
It cools down and forms condensation
What are factors that affect surface temperature ?
- Heat input into a home: time of day, affordability
- Heat loss from home draughts, ventilation strategy & thermal insulation
- Locations with home: thermally isolated corners & gaps in insulation
What is interstitial condensation?
interstitial condensation is a type of condensation that may occur within an enclosed wall, roof or floor cavity structure, which can create dampening. When moisture-laden air at dew point temperature penetrates inside a cavity of the structure, it condenses into liquid water on that surface.
what is the purpose of ventilation and how can it be archived
- Ventilator reduces moisture
2. Keeping a window a jar, extractor fans
How can condensation be avoided
VENTALATION
- Close kitchen and bathroom doors when these rooms are in use. This will help prevent moisture reaching other rooms
2, Do no block air vents
Mechanical Ventilation
The process of changing or replacing air in any space to provide high quality indoor air, by removing unpleasant smells and moisture
How can heating and insulation prevent condensation from occurring
Good installation of the building creates warmer wall and ceilings, therefore, inhabits mould growth by preventing condensation from forming on them
What is the equation for resistance
R = d (Thickness in m) / Conductivity (W/M.K)
What is the unit for u values
W/m².k
what is the equation for heat loss through a wall
Q/A = U-value x change in temperature
What is the equation for total resistance
R(total) = Rsi + Rs1 + Rs2 + Rs3 + ect. + Rso
