Ventilation Louvres

What factors determine the amount of natural ventilation available in a room?

Public Comments

1. In the HVAC industry, the amount of natural ventilation is typically expressed in terms of area, e.g., square feet. Many factors can be looked at to determine the amount of natural ventilation. Mechanical codes can be used to establish a minimum amount, e.g. 1 square foot for every 1000 square feet of floor space (just an example, not the correct numbers). For more critical applications, people go to the extent of using computational fluid dynamic modeling software to determine the amount of natural ventilation. Here's a grocery list for basic natural ventilation concepts: 1. What are you trying to ventilate? A home, a utility room, etc. Kicker here is, is the ventilation for people, animals or stuff? People and animals need fresh outside air, stuff doesn't. Fresh air is outside air obtained from a uncontaminated source. Bringing in fresh outside air from a source near a stinky dumpster or parking lot full of stinky cars for example is not a good idea. 2. How tall is the room? Taller rooms have better potential for natural convection. Warm air rises. If you can vent the top and bottom of the room, this will enhance natural convection. 3. What direction are the prevailing winds? Orienting windows, wind scoops. etc. in the direction of prevailing winds will take advantage of the wind. 4. How much wall space is available for ventilation openings? Are there any architectural concerns? Do you want it look nice? 5. What's your budget? Hope that helps.