Making a portable air conditioner more efficient
Posted: Sat Aug 14, 2010 2:21 am
Most portable air conditioners only have one hose for the condenser heat exhaust. Where do you think the air to cool the condenser comes from? In the house. Where is it going? Outside.
This same air has been cooled by the evaporator side and is now being thrown outside. See where I am getting at? You are basically producing cold air, but getting rid of a large portion of it. This is not all, if air is being put outside, then air has to replace it. Where do you think it comes from? Outside, through various cracks that may exist in your house. Maybe the hot water heater flue, an opened window etc. In fact to get an idea of how bad this is, turn your unit on, and open a window just a crack. You'll have hot outside air blowing in your face!
There is a solution to this however. It really depends on your unit though, but I would assume that most units have two intakes. It may look like there's just one but if you inspect your unit well enough you'll probably see that there is a separation or something. There is one intake for the condenser, which is needed to cool down the compressor and get rid of it's heat. There is another intake for the evaporator, which is where the real work gets done. The air passes through, is cooled down, then shot back into the room.
Once you locate the condenser intake, what you want to do is build some kind of air box that sits up against it, with a tube the same size or bigger then the exhaust, and goes outside. Try to separate them as much as possible, or at least, make sure the exhaust is higher then the intake as you don't want exhausted air to go back in the intake. This intake will avoid wasting some of the cooled room air only to exhaust it outside, and also prevent hot air from being sucked into your house from various cracks and possible entry points, making those rooms hotter.
My setup is attached.
Also note the insulation on the exhaust, that alone helps a lot too. It's more bulky to move this setup around though, but eventually what I plan to do is find a way to set it up in the basement in a more permanent fashion. I'm thinking of maybe hooking it up directly to the duct that goes to my office and use a booster fan. There would be a A/B damper setup to choose between the furnace, or the unit, so I just basically bypass the rest of the hvac and just shoot air directly into the duct to the office. This setup would also be much more quiet. I could setup a thermostat in the office that opens a relay to turn the unit on/off as needed. Maybe that will be a project for next year.
Archived topic from Iceteks, old topic ID:5170, old post ID:39440
This same air has been cooled by the evaporator side and is now being thrown outside. See where I am getting at? You are basically producing cold air, but getting rid of a large portion of it. This is not all, if air is being put outside, then air has to replace it. Where do you think it comes from? Outside, through various cracks that may exist in your house. Maybe the hot water heater flue, an opened window etc. In fact to get an idea of how bad this is, turn your unit on, and open a window just a crack. You'll have hot outside air blowing in your face!
There is a solution to this however. It really depends on your unit though, but I would assume that most units have two intakes. It may look like there's just one but if you inspect your unit well enough you'll probably see that there is a separation or something. There is one intake for the condenser, which is needed to cool down the compressor and get rid of it's heat. There is another intake for the evaporator, which is where the real work gets done. The air passes through, is cooled down, then shot back into the room.
Once you locate the condenser intake, what you want to do is build some kind of air box that sits up against it, with a tube the same size or bigger then the exhaust, and goes outside. Try to separate them as much as possible, or at least, make sure the exhaust is higher then the intake as you don't want exhausted air to go back in the intake. This intake will avoid wasting some of the cooled room air only to exhaust it outside, and also prevent hot air from being sucked into your house from various cracks and possible entry points, making those rooms hotter.
My setup is attached.
Also note the insulation on the exhaust, that alone helps a lot too. It's more bulky to move this setup around though, but eventually what I plan to do is find a way to set it up in the basement in a more permanent fashion. I'm thinking of maybe hooking it up directly to the duct that goes to my office and use a booster fan. There would be a A/B damper setup to choose between the furnace, or the unit, so I just basically bypass the rest of the hvac and just shoot air directly into the duct to the office. This setup would also be much more quiet. I could setup a thermostat in the office that opens a relay to turn the unit on/off as needed. Maybe that will be a project for next year.
Archived topic from Iceteks, old topic ID:5170, old post ID:39440
