How to improve efficiency of portable air conditioner AC units to cool rooms faster 

You’re welcome!

Lazy man, just move the unit lool

@@krzywik13you need to work on your comprehension of the English language, the point I made has nothing to do with the unit location. Re-read and comment after you’ve fully understood the context. In which, you’ve obviously hadn’t yet.

That's why you should only buy a dual hose system

​@@robertclark8546 Indeed! _Unless_ you actually want to pull in air from the outside, which _may_ be a goal for some. I'm actually considering just sticking with my single hose portable (instead of dual hose or even a mini-split) since a _second_ issue I have in my room (in fact, in my home which is well sealed and insulated) is that it doesn't get enough fresh air ventilation from outdoors; the bathroom fans only do so much. So in a way, this can work well both for cooling the hottest rooms in a top floor as well as forcing fresh air from outside, which might not necessarily be bad. That said: 1.) This guy's setup needs balanced air *very* badly, since he's in a super hot/humid climate and 2.) I'm in a very well insulated room in a well insulated house in a moderate (but sometimes warm) climate. Coincidentally, I'm in the Pacific Northwest and right now it's relatively comfortable outside and only hot on occasion. I only need a window AC precisely when it's moderate but only slightly warm outside, lol. So, 78-80 degrees for me spells discomfort, since my 140sqft office will ramp up to 82+ while the rest of the house sits at 71 (from the central AC cooling over night). 😅

Nice job!

Is it humid in Madrid as well?

@@Jordan-or8wu Not a chance!! This month its about 25-30%. Madrid is 660m above sea level & 500km from the ocean!

where can i get one the unit just came with the pipe and a plastic bag type window seal

@Paul-hl4cj check my video description 👍

thanks looks like the sleve is not one sise fit all but the silver role can fit any size do you have a comparison heat lost vire sleve and wrap but its still a fab idea will look for some foil wrap at homebase ty

Nice 👍

I noticed the same thing which is what led me to try this. Good luck.

As the RU-vid video says, the duct connectors use brittle and plastic tabs. Trying to tape or connect insulated duct that doesn’t fit the connectors would result in hot exhaust leaking back into the room.

Do you have a video to show how to do it?

Realize, you could put on a thousand mile an hour exhaust fan, and it would suck all the newly made cold air out of the room as soon as it's blown out the unit. There's a balance between the high temperature of heat per volume unit in the exhausted air, and lower heat temperature per volume unit of outside air being sucked through the house crevices to replace it. Ideally, you want hotter air exhaust with a lower air flow than less hot air exhaust with higher air flow. However, since the insulated exhaust pipe is holding the heat better now, it will also be hotter near the unit, and thus by back pressure, inside the unit will feel it, and run at a higher temperature, lowering the life and making the unit stressed and more inefficient. So it seems the extra outside fan on the exhaust rube might be warranted. How to determine the outside fans power needed is an issue. To get that super-heated air away from the unit's heat coils quicker, instead of adding an outside fan to increase flow to remove the heat better from the coils by using a higher volume of expensively room-cooled toom air - a better solution would be to use the smooth walled metal dryer ducting. Corrugated flex tube effectively creates a lower insider diameter, stratifying air near the inner walls due to turbulence trapped it in the grooves, reducing the effective diameter of the pipe. Also, notice the higher heat reading at the bend. Bends reduce flow by 30%. Ideally, the unit could be placed right on the window sill on a purpose-built shelf, with a short run of STRAIGHT smooth pipe through the window, with NO bends. It should go out the window a foot, angled downward slightly,- so rain doesn't enter - and then the heated air won't radiate back through the window pane. This is for a single pipe. A double pipe is much the same.

Ya the FLIR was a fun way to confirm if it did anything and also verify I didn’t have any gaps/leaks in the insulation. This morning it did seem to drop the temperature faster in the garage than before. Shortening the duct was a smart idea you had too. It probably lessens air resistance for the exhaust air as another efficiency gain.

its warm air its not exhaust so it’s perfectly safe

Thanks 👍

OK here's my question.... If that's the case....how the hell do these things work so well? I mean, it sounds like you're saying the AC is sitting there running, pumping the air it just cooled out along with the hot air....creating a vacuum drawing hot outside air back in to replace what air is being exhausted out.... This sounds like a complete losing battle......so again I ask... how do these work so freaking well? I don't get it.

@@One-Day-After-Another Well, it is not a "complete losing battle", just a major inefficiency that can be mitigated as I described. The magnitude of the inefficiency will vary according to your circumstances, such as the outside temperature, and location of the room in your house that you are trying to cool. I installed a portable AC in an upstairs room in my house that I am using as an office. There are also two other bedrooms and a bathroom upstairs that are not being used at all. Each of the the 4 upstairs rooms has recessed light fixtures which are by design not air tight, to keep the light fixture from overheating when incandescent bulbs are used. So they provide an air flow path to the highest/hottest part of the attic. The air in the attic when it is 95F outside, and the sun is shining, can be well over 140F. I closed the doors to the 2 bedrooms to reduce air infiltration to the office, so the portable AC would be trying to cool mostly just the office. When I hooked up the portable AC per the user manual instructions (pulling room air into the unit to cool the condenser, then ducted out the window) it did NOT do a "freaking well" job of cooling the room. Also, the 2 bedrooms that were closed off reached temps over 100F. (Thanks to the attic air and outside air being drawn in to replace the office air.) So, I added a 2nd duct (per my original comment) to bring outside air into the AC to cool the condenser. It then did a much, much better job of cooling the office. So, it boils down to just improving the efficiency of your setup wherever you can.

@@spud1 We have a hot attick single story house..and the house gets little shade.... Once during a heat wave our ac went out. someone had their portable AC in storage... I didn't even know those existed at that time... Anyway... we were desperate until our AC could get fixed... and not knowing anything about what I know now... We were shocked how well it worked.. We actually fought over it....we put it in one bedroom closed off and when you walked in that room it felt so cool...while the rest of the house was miserable... so that's what I meant by working well... It was so hot... yet even with the inefficiency it was still able to cool the room... I feel like dual hose units will start to take over instead of single hose... I've noticed this more lately.. even one of them has dual hose built into one big hose.. so it looks like single hose but it's dual..

​@@One-Day-After-Another Yep. It's because it was siphoning that return air (i.e. air returning to your portable AC) from the rest of the house, which was depressurized. One test you can do is close the door in that room with the portable AC. You'll notice that there's quite a lot of air flooding into the room from under the door or the pass through grilles that connect that room to the rest of the house. That said, I'm sure the rest of the house might have already be a bit uncomfortable, but the portable AC was likely making it even worse due to how it's depressurizing. What is happening is that it is making up that air by pulling it in from the little cracks in the walls, around doors, windows and etc. That air is of course warm/humid. That's why dual-hose portable AC units are often far better in climates that are really hot/humid, since they ensure the pressure stays balanced in the home and your already conditioned air stays inside of your insulated envelope of your house.

the same thing happens with most ac's they pull in cold air and exhaust hot air your car has this option aswell

We bought one last night to help our AC units out. For nights it’s wonderful but the humidity summer days don’t mix well with it at all. Returning it today and getting a fan to help circulate the cold air from our bedroom AC unit.

I laughed so hard when I saw it, like it's already setup for it!

I'm curious how pulling hotter air from outside (vs already cooled air from inside) would create an efficiency gain. Doesnt the unit have to work harder to cool warmer air??

I thought the same initially but learned from commenters that the intake air is used to cool the compressor and then exhausted using the second hose in a semi-closed loop. Without the second hose it creates a bit of a vacuum drawing in air from adjacent rooms or outside. Setup this way (with two hoses) the conditioned air is recirculated without introducing air from outside the room which may be hot or humid.

@@kristinlogan7509 the oposite. the way AC systems work, the way he has it set up, you're actually warming up already cold air because his hot and cold side are not isolated. And this is essentially the biggest problem with AC systems that don't have dual hoses. Even if it's hot air from outside, the way an AC system works is that it needs to remove heat from the air inside the room not so much move the air itself. the TLDR: AC systems shouldn't remove hot air inside a room. AC system should cool the air inside the room. AC systems shouldn't move air from inside the room to the outside of the room, AC systems should MOVE HEAT from the inside of the room to the outside of the room. The hot air outside the room is still cold enough to remove heat from the refrigerant of an AC enough to continue removing heat from inside the room. By not having an intake, from outisde, you're warming up the already cool air from inside to remove heat and send it outside, but now the AC has to cool new air. This is also why opening your refirgerator doesn't cool a room. because the refrigerator is still inside the same room you're trying to cool. this is why the "recirculate air" option inside your car helps cool the inside of a car faster than not recirculating air. It's not about removing hot air. It's about removing heat from the hot air. now here's the long version. Though I'm sure you can find youtube videos on how an AC system works but here's my attempt in simplified terms: An AC system works by having what essentially is two radiators (Let's call them that to make it more simple for people to understand, I know one is called a condenser and one is called an evaporator). One of the radiators is at high pressure, and the other is a low pressure. in an ideal system, the high pressure is outside the room you're trying to cool, and the low pressure is inside the room you're trying to cool. Prior to first starting up an AC system, both the low and the high pressure is at a ambient temperature. when starting the AC, the cycle begins, the compressor begins to push the gas into the high-pressure side, think of the gas as a wet rag, the gas holds heat like a rag holds water, before wringing the cloth, water stays in the rag because there's room in the rag to hold water. gas likewise is at ambient temp when it's been sitting stagnant. However, upon moving into high pressure, all that gas is squeezed into a tighter space causing all that heat energy to be squeezed into that same space. Heat energy wants to equalize, therefore the now hot high pressure in the outside radiator is now hotter than the already hot air outside. doesn't matter if the hot air outside is hot, it's still cooler than the now compressed gas. The heat energy moves from the hotter gas, into the hot air equalizing the compressed gas temperature to match again the outside ambient hot air. When the gas is now at ambient temperature again, the hot gas moves now to the cold radiator, or the low-pressure radiator. here the gas expands and think of it as a rag that has had all the water wrung from it ready to collect more water. In this case the gas is cool enough to be able to accept more heat from the room inside trying to be cooled. but keep in mind you're not sucking the air out of the room; you’re simply moving air through the radiator inside the room and but keeping the air in the room to remove the heat from that air. once the gas has collected all the heat, it's now pushed back outside to be squeezed again and have all the heat squeezed out of it again. And thus, the cycle continues. Each time this cycle continues the cold air inside the room gets even colder because it's continously having heat energey removed from it each time you pass it through the low pressure radiator. Because you're REMOVING HEAT, not the air itself. Therefore, an AC system doesn't work by introducing cold air. It works by removing heat from the air already inside the room. However, by him not having an intake hose, he's using the already cold air to remove heat from the AC and blowing that previously cold air back out to outside the room. why would you want to intentionally warm up already cooled air. Therefore, if your AC comes with two hoses, you ALWAYS want to use both hoses. therefore, a window AC always has to have the back of it sticking outside.

@@kristinlogan7509 You are still pulling in hot air from the outside, because all the air you are pumping out has to be replaced from somewhere - guess what, the only source can be from the outside hot air. If it wouldn't be replaced from outside, you would suffocate in a vacuum. This is why whenever you can, you should forget moving air and move the heat instead with a proper split AC.

Thanks I love my clubs

Makes sense but I’d probably just go the extra step and install a mini split at that point

@@reallyMello . What size hole does the smaller mini-split require? I'm curious....I've not done one yet...

Depends on the unit but much smaller since it just needs to run the refrigerant loop to the outside unit and the condensation line

Great, let me know how it goes

@@reallyMello Works great! The exhaust pipe is now no longer warm, and the room feels cooler too!

@@95ellington nice! Thanks for letting me know.

Awesome

thats what I did. It helps but hose is still releasing a lot of heat. im insulating mine for this summer.

That is optional and depends on how hot the air is outside the room relative to the inside. If the inside air is 85 F and the outside is 95 F and humid it wouldn't make sense to use the intake duct (as in my case). As Whynter explains it on their FAQ page, "A dual hose portable air conditioner will cool a room faster and will help minimize negative air pressure situations in the room. If the outside temperature is much higher or more humid than the room, you can cover the intake hose with the included cover, and it will function as a single hose unit."

The inefficiency of a one vent portable AC or not using the intake hose on a dual, causes air from the outside to be sucked in from all the tiny gaps in the house. When you push air outside the air has to flow in from somewhere to equalize the pressure. A dual hose system makes a closed loop of the outside air flow when hooked up properly. Which is more efficient than causing a constant flow of outside air coming into your house.

@@reallyMello I don't think you understand. The air conditioned air has a different intake. It's a closed loop. If you properly use the dual vent then the outside air is second closed loop, like a central AC. The way you have it setup will cause outside air to get sucked into your house, losing efficiency. Using both vents will lower the humidity more too.

@recoveryguru For it to be a closed loop it would need to be recirculating the same air. When you are dumping out exhaust air through the window you have created an open loop that, as you state, needs replacement intake air from somewhere, either the surrounding spaces or the optional second duct connected to the outside--but that is fresh air, not a closed loop, not recirculating. So in situations where that input fresh air is significantly more hot and humid than the space you are conditioning there isn't a benefit of using the second hose. In cases where the intake air is milder or less humid, yes. A central A/C is a closed loop because it recirculates the inside air and transfers the heat out via the coolant loop to the outside compressor that is cooled off with the compressor fan using the outside air vs the compressor being housed in the same space as with portal units where you need to duct out that waste air which needs replacement air from somewhere.

@@reallyMello I guess I used the wrong terminology. I mean the inside and outside air are are kept separate in a dual system. You run an AC when it's cooler outside? 😲

You’re welcome

I don’t think it would do as well no. The airgap in the roll insulation I’m using would be more effective at preventing heat transfer then foil alone.

Great idea, I will try that first, sounds like a great idea

It allowed it to cool the room in less time than before and also when I'm near the duct I'm not feeling the radiant heat coming off the it

Interesting. Where are you ducting the intake in from in your setup?

From the condensor intake vent

I think the cold air from the evoporator coil is mixing With the Hot air from the condensor coil because of the poor insulation which seperate the two part

@@devtechsavvy7125does using the fan to blow air into the air intake help any?

While I agree that leaking in of outside air from the vacuum they create lowers the efficiency when compared to sealed recirculating systems that doesn't mean they "cannot work". It's fair to say they wouldn't reach the efficiency of a window unit, mini-split, or central A/C that recirculate the air without creating a vacuum. However, when a portable unit is what you have to work with insulating the exhaust duct, as shown here, is a way of helping improve the efficiency of the given system as well as keeping the duct short. The vacuum aspect is an important consideration though so thank you for mentioning it.

@@reallyMello I literally taped a cardboard box over the condenser coil intake and routed a 6" duct from outside into the box improve efficiency. It works a LOT better this way and can cool a larger space.

@@donovanhill7367 I think all these units should have 2 air tubes. It's incredible no company producing these ACs has ever thought to that solution. EDIT: I just discovered they invented them and are called "dual hose" but I don't find them here in italy.

you got it, these units are flawed by design. In the past there were portable split systems on the market, with external condenser, now they are very rare and cost at least 5 times these with tube, I think they were much much better

Why shouldn't you run hose vertically? Doesn't heat rise? Excuse me if a silly question. I agree with the shortest root to the window exhaust.

I’m with you Mick, I get shortest route is preferred but I don’t get why a vertical run is a problem since heat rises unless you just want to avoid 90 degree bends which would make sense since that would add resistance to flow

I misunderstood what the advantage was supposed to be of the second hose at the time.

@@reallyMello We have a Media Duo the 2 hoses in one plus an inverter and it cools our bedroom down to a meat locker in just half an hour. The hose doesn't get hot because it draws in outside air and no pressure drop in the bedroom.

That’s great!

​@@MHdollrevievswhere did you buy it? I'm not seeing dual hose model.

@@denisebrock6882 We live in Canada and we bought ours a Media duo at Home Hardware August 23 as they had them on sale, It cools our bedroom to a meat locker. Media makes several models for different manufacturers the Dandy version sold at Costco is basically the same unit.

It can be used in either config, but as other have pointed out in the comments its generally better to hookup the inlet to a duct drawing in from the outside to cool the compressor and not create a vacuum in the room (drawing in air from adjacent spaces)

@@therealthreadkilla adding a booster fan to the duct is maybe an idea to overcome the increased pressure from having a long run

There sure is a nicer way to make your point

Nope

That’s kind of the concept behind hybrid water heaters sort of in reverse. They use the a compressor to heat the water and actually exhaust cold air-which is nice because it helps cool down my garage a little.

They typically aren’t insulated to the same degree and you need to be careful on opening diameters. Connecting a second tube would help in my case as well yes.

Mine is supposed to self evaporate with the exhaust air but there have been a couple rare times I’ve needed to drain via the plug

I have mine elevated up on an old solid end table and have the tubing Into a deep bucket so water runs out

Bought portable a/c unit last year and had it draining into a really big plastic round storage tub. Dumping the accumulated water out twice a day was annoying. Looked at getting small aquarium style pump with long tubing to drain the water possibly out the window. Window screens in my home are pretty old. When I can afford a new window mount a/c unit or a mini split I plan to upgrade. But for most of last summer & again this summer…. cut a small hole in window screen & attached a hose to the drain at the back of portable a/c unit. Put the a/c unit on an old end table (it’s solid heavy wood), and put the water drain hose out the hole in window screen. That window is just off of my concrete front porch and the water from a/c drain now waters the flowerbed adjacent to porch, under that window. Mine isn’t the prettiest diy insulation job around the window air hose vent & the a/c water drain. But it’s a temporary solution until can save up for home improvement.

I cut rigid foam insulation from the hardware store to make that

Exhaust yes. Intake no.

So cute

It did for me. Very noticeable especially when working closer to the unit. It will depend on how long your duct is as well.

@@reallyMello fair enough..👍

PVC wouldn’t insulate by itself either and would make it harder to connect to a portable unit

@@shannonRoy-x7k not with the angles I had to work with at the time

@@reallyMello oh that makes sense 😊

Sounds like there is a lot of humidity in the space you are conditioning

Amient Humidity

Try cleaning your filters.

What happens if I use only the upper drain port?

That’s maybe an option if it’s matching diameter but they aren’t typically as well insulated either

In my case the unit was free so making the best use of it. Second, when the window is a slider instead of single/double hung your options are limited.

Ya the hoses are a bit pricey relative the DiY approach but have a cleaner look if it’s going somewhere that may matter more I suppose. The efficiency gain of an insulated hose or the foil roll will pay itself back eventually.