I think I’m missing the most important part of this debate. How does the second hose help? The air outside is hot; with one hose, hot air enters the house because of the vacuum effect; with two hoses, the second hose explicitly sucks in air from the outside… which is still hot. Where is the difference?
From the wirecutter test conditions above it sounds like these are also meant to dehumidify:
we measured the temperature and humidity in the room every 15 minutes for three hours to see how well each unit dispersed the coolness and dehumidification process across the space.
With one hose, you presumbly get that for free if the air inside is more humid than the air that replaces it. With two hoses, since you’re not mixing air, do you still dehumidify? (If anything I’d expect the opposite, since the same amount of water vapor is apparently higher humidity in a cool room than a hot room.)
Wouldn’t the AC unit have to intake cool air from the room (since it’s expelling cold air into the room), and mix the cool air with the warm outside air? (Maybe the numbers work out differently in this condition but I’m not convinced yet, would have to see a calculation)
A two hose AC does take in both indoor and outdoor air, but they never mix. (The two hoses both carry outdoor air; indoor air is pumped through two vents in the AC.) The AC just pumps heat from the indoor air to the outdoor air. Similar to a fridge.
I think I’m missing the most important part of this debate. How does the second hose help? The air outside is hot; with one hose, hot air enters the house because of the vacuum effect; with two hoses, the second hose explicitly sucks in air from the outside… which is still hot. Where is the difference?
With two hoses, the air sucked in never mixes with the cool air in the room; it’s kept completely separate. Only heat is exchanged by the AC, not air.
From the wirecutter test conditions above it sounds like these are also meant to dehumidify:
With one hose, you presumbly get that for free if the air inside is more humid than the air that replaces it. With two hoses, since you’re not mixing air, do you still dehumidify? (If anything I’d expect the opposite, since the same amount of water vapor is apparently higher humidity in a cool room than a hot room.)
Wouldn’t the AC unit have to intake cool air from the room (since it’s expelling cold air into the room), and mix the cool air with the warm outside air? (Maybe the numbers work out differently in this condition but I’m not convinced yet, would have to see a calculation)
A two hose AC does take in both indoor and outdoor air, but they never mix. (The two hoses both carry outdoor air; indoor air is pumped through two vents in the AC.) The AC just pumps heat from the indoor air to the outdoor air. Similar to a fridge.