You would be correct if your fan was guaranteed to always push a specific volume of air. But that's not how it actually works. Your fan is able to push air up to a certain pressure. That pressure is immediately after the fan, from there the air wants to equalize to lower pressure areas which is ideally the rest of the house. But what we're seeing here is that restrictions cause those high pressure bubbles inside the ducting which means the air doesn't navigate to low pressures as quickly. The ultimate result is reduced air flow out of the vents.
Think of it like a garden hose. If you put your hand on the hose, then you'll be getting less total water out. It'll spray farther because it's still high pressure as it exits the hose, but you get a much lower total volume of water. Your finger is that flow restriction, and the hose isn't able to produce any more flow than the pressure provided by the city.
So allegedly the thicker 12-month filter is more energy efficient than the thinner 1-month filter. More available surface area for air to move through. Unless Gemini is lying to me again…
18
u/round-earth-theory 2h ago
You would be correct if your fan was guaranteed to always push a specific volume of air. But that's not how it actually works. Your fan is able to push air up to a certain pressure. That pressure is immediately after the fan, from there the air wants to equalize to lower pressure areas which is ideally the rest of the house. But what we're seeing here is that restrictions cause those high pressure bubbles inside the ducting which means the air doesn't navigate to low pressures as quickly. The ultimate result is reduced air flow out of the vents.
Think of it like a garden hose. If you put your hand on the hose, then you'll be getting less total water out. It'll spray farther because it's still high pressure as it exits the hose, but you get a much lower total volume of water. Your finger is that flow restriction, and the hose isn't able to produce any more flow than the pressure provided by the city.