Internal weather

    1. Wind sucks
    2. Cross ventilation
    3. Stratification
    4. Convection
    5. Moisture
    6. Latches and locks
    7. Vents and voids
    8. Tackling the large
    9. Exposing the small
    10. Being universal



Wind sucks

  • It’s sucked from high to low pressure, pulled not pushed to fill a void.
  • Invisible pathways through the home and the limitation of the air pressure test.

It’s not blown.



Cross ventilation

It can’t get in.

  • Closing internal door. Opening opposing windows.
  • External weather rurally has a consistent and persistent direction, hunting for draught on a windy day and when there’s a change of direction.

If it can’t get out.




Warm air rises.

  • Having a little more energy requires needing more room to dance about, warm air is more buoyant and floats to the top of the room or top of the house.
  • If it escapes out from the top it pulls cooler fresh air in at the bottom to replace it.

As it cools, it becomes heavier and falls




Interacting with thermal mass and cold spots.

  • As the air is cooled by the building fabric, density increase and it begins to fall.
  • This pulls the warmest air to the coldest spot.

Conveying moisture from the source to the symptom.




Warm air carries more moisture.

  • Cold surfaces reduce air temperature.
  • If they are slow to respond condensation will occur.
  • Quick to respond and the energy is captured.

Responsive surfaces capture energy from moisture.



Latches and Locks

Do what you can.

  • Operating windows and doors.
  • Operable latches and locks.

Where you are with what you got.



Vents and voids

Pushing air out against the prevailing wind.

  • Pushing marshmallows up a chimney.
  • Extractors, air bricks and the 5mm continuous gap.



Tackling the large

Air being pulled through a building.

  • Start with the large.
  • Cardboard box foamed into the chimney.
  • Gaps in the floor boards add up to a large hole likewise the invisible hairline cracks.

Taking the path of least resistance.



Exposing the small

With the larger holes filled.

  • A well draught-proofed house causes the wind to whistle through the keyhole.
  • Or up the loo.

Air is now pulled through and exposing the remaining small gaps.



Being Universal

Fitting products in isolation is unlikely to reduce air change significantly.

  • Enough to bring down your bills although and re-route and annoying draught.
  • Being universal requires tackling the large, exposing the small and addressing the invisible.
  • Adding friction certainly helps slow things down.
  • Keep internal doors closed will slow the passage of air through the window

When it’s cold outside it’s generally still, likewise, when it’s windy it’s usually warm. Turning down the heat will reduce the pressure pushing air out of the house.