Explain this article, please.

WIAWSNB

https://edconway.substack.com/p/the-missing-pipe?utm_campaign=email-half-post&r=2ir9r&utm_source=substack&utm_medium=email

In essence, it says that portable air-con units available in the UK come minus a second duct that would increase its effectiveness two or threefold. A second duct should draw the unit's air in from outside, just as the vent pipe fires it out.

I don't understand. Why draw in warm air from outside instead of - as you'd do in a car (recirculate) - reuse the already cooled air from within?

grumpy_codger

All aircons, be it split or portable, recirculate the air inside and cool it. However, you cannot cool without heating something else at the same time.

Split systems (including car aircons) heat the outside air making it even hotter.

Bad portable aircons have only one-way hose. They take some (already cooled) air from inside, heat it and blow outside. This air gets replaced by some other warm air getting inside though various gaps.

Good portable aircons have a double house (like a modern boiler chimney) - they draw hot air from outside through one hose, heat it and blow even hooter air back outside. Cooled air inside remains unaffected - this is real 'reuse' or recirculation.

GDB2222

Of course, portable ACs recirculate, as you would in a car.

However, they need air to cool the AC fins that get hot when you extract the 'coolth' from them and use it to cool the recirculating air. The article is suggesting using air from outside for that purpose, and then exhausting it outside. Instead, single hose ACs use air from the room, thus wasting the coolness of that air.

There is at least one split unit portable AC around. The Midea PortaSplit.

Lorian

With some DIY skills easy enough to add a plenum and second hose to single hose system. Needs a dual hose window outlet too.

grumpy_codger

https://forums.moneysavingexpert.com/discussion/comment/82081904#Comment_82081904

There is at least one split unit portable AC around. The Midea PortaSplit

Looking at some pictures, it is split portable, with two portable units connected by flowing liquid, not air hoses that the article was about. The picture below shows a (non-split) portable aircon (left) with a second air hose (vs one hose on the right).

stuart45

The article is by a journalist, not a HVAC engineer. The external air on a dual hose system is used to cool down the condenser. A single hose unit creates a negative pressure and draws hot air into the cooled room from the rest of the house.

mta999

An air conditioner with one hose sucks in air from your room and splits it into hotter air and colder air

the colder air gets blown into your room and the hotter air gets blown outside via the single pipe - so far so good

Unfortunately blowing the hot air outside creates a 'vacuum' in your room which means that air seeps in to equalize the pressure (from under the doors etc) so basically you just get more warm air sucked into the room

WIAWSNB

Ah! Thanks everyone - that makes sense.

GDB2222

https://forums.moneysavingexpert.com/discussion/comment/82081918#Comment_82081918

Yes. It means you have the efficiency of a split unit, but you don’t have an ugly air conditioner on the outside of the house all year round.

Momogeew

That ugly air conditioner on the outside of your house can be sited anywhere - i have mine on the wall at the back of my house, actually, it's on the ground on fat, rubberised feet.

The only person that can see it is me and the pros outweigh the cons.

Albermarle

https://forums.moneysavingexpert.com/discussion/comment/82081985#Comment_82081985

They do seem to be a good alternative, depending on the layout of your house. Typically the internal part sits on the floor by a window and you have to feed an umbilical cord through the window opening to the outside part.

So not as neat and tidy as a fully installed split system, but cheaper !