Do The Portable Room A/c Units Work?
Looking for reports of suitability from people who've used one of the common (Home Depot / Lowes ) portable air conditioner units. Need to know how good a job they'll do cooling a room. Judging by what I know of thermal principles, the can't work. Where does the heat go? We know that to cool/chill air, you remove heat from it. In other systems, the heat is "pumped" outside. With the self contained unit in the room, seems like it could never get ahead because it's not isolating the heat anywhere. Additionally, most of your air chillers have dehumidifcation as a by-product. So where's the water going in these units? Maybe they've got a concealed bucket you have to go dump periodically. Anyway, I'd like to get a couple for use during power outages when we're running on our gensets, but need to know first that they really work. Otherwise, I'll use window units.
Answer:
They do work. I have one and the air coming out is very cold. The only problem with them is that they suck air in from outside to replace the air the blow out the vent through the window. Very inefficient. The condensation either goes to a bucket, out a tube, or is evaporated out the exhaust depending on type of unit you have. These things are good if you can't use a normal window unit due to no window or you dont want it sticking out the side of your house. Both ways now. Some draw air from the ( 1 ) room for the evap and cond coils, many newer ones ( 2 ) draw outside air in one hose and blow the cond air back outside with a second hose. These units "barly" operate cooling a room when compared to a window unit, but they will cool. I bought a DeLonghi unit 4-5 years ago (approx $800 at the time!) and am pretty disappointed by it. It is wimpy, doesn't cool as well as a much cheaper (and lower BTU) window unit. Cycles constantly. Thermostat has a hair-trigger response, either "always on" or "not on enough". Noise level higher than a window unit even though it is advertised as "whisper quiet". Fit and finish poor (front door rattles, compressor vibration noise) Would not want to sleep in a room next to this thing. The thing is obviously going to be less efficient than a system that keeps inside air inside, but: If a quantity of air Q1 comes into the room and is separated into to other quantities, a hot, wet Q2, and a cold, dry Q3, and Q2 is exhausted outside, then the air inside Q4) will obviously be cooler and dryer than Q1. (but warmer and wetter than Q3). If you assume the worst-case, that Q1 mixes thoroughly with Q4 before being sucked into the unit, then you should *eventually* reach equilibrium at q4=(q1+q3)/2. If you get the best case, where ALL Q1 goes through the unit before mixing, then you reach equilibrium at q3.