Air conditioning

Surrey1966

Good morning wise ones

I'm after help/advice re air conditioning - I'm probably looking for the impossible:

not looking for a fan, or a fan cooling air over ice packs etc - but also I cannot have an exterior air con unit/condensor on an outside wall. Would prefer one that does not have a hose that needs dangling out of a window either, but willing to compromise on this. There seems to be so many products claiming to do everything I want but I find most hard to believe - and some unaffordable.

Accommodation: 1 bed flat, lounge, small kitchen & bathroom - has 3 exterior windows - flat is rented and not permitted to have anything fitted as such.

thanks for everyone's input so far, much appreciated and very helpful

MyRealNameToo

AC works with a heat exchanger to take the heat out the air and blow the newly cooled air out. That heat has to go somewhere. If you get rid of the heat by sticking it in a hose out the window then you also need to be replacing the air you are removing. Most basic air conditioners have a two in one pipe but that means the air its pulling back in is going to be mainly the hot air it just kicked out.

The other issue if lifting a window to put the pipe out also leaves a big gap around it where hot air comes back in. If you have sash windows then there are easy/common solutions but UK have many more pivoting windows which makes filling the gap more complex.

This is one of the reasons why portable ones are so much less efficient than fully installed ones, in those they use a liquid to move the heat to the external heat exchanger which removes the problem.

Albermarle

There are flexible split A/C units, they work like installed ones ( so not like portable ones). However the part that goes outside has to sit on something solid, like the ground/flat roof/balcony.

PortaSplit

ComicGeek

https://www.powrmatic.co.uk/products/air-conditioning/powrmatic-vision-h20/?_gl=1181a9yd_upMQ.._gaOTk0MjcxNjgyLjE3ODg5NDM0Njg._ga_KVJXQVQTG4*czE3ODg5NDM0NjgkbzEkZzEkdDE3ODg5NDM0NzAkajU4JGwwJGgw

https://cooleasy.co.uk/products/powrmatic-vision-h2o?srsltid=AfmBOoqHoR8NJF86f0avDrJymylyrXY257BXDa-x-TQvRhAHprEkU79U

This is an alternative - a permanent AC unit (which might be an issue in rented accom as you do really need to fix it to the wall), but doesn't need a duct or holes or outside unit. Does need a water connection and a drain connection, but might be something that could be set up neatly as a temporary connection.

Could find some way to capture some of the (clean) waste water and use it for flushing the toilet etc, as a waste otherwise.

Not cheap, but sits between a portable AC unit and a full installation in terms of cost and effect.

QrizB

I'm after help/advice re air conditioning

As you might imagine there have been a few threads on air conditioning this summer! Several of them are on the heat pumps forum but there are others too.

I cannot have an exterior air con unit/condensor on an outside wall. Would prefer one that does not have a hose that needs dangling out of a window either, but willing to compromise on this.

As stated above, air conditioning works by taking heat out of the air and moving it somewhere else (usually outdoors). So you need somewhere for the heat to go to, generally either an outdoor unit or a vent hose. The water-cooled aircon above is interesting but has other drawbacks that I'll come to later.

There seems to be so many products claiming to do everything I want but I find most hard to believe - and some unaffordable.

I posted the following in the "cooling towers" thread but I'll copy-and-past it here too.

In order of efficiency/effectiveness (most effective to least) and cost to purchase & install (most to least)

1. Proper split aircon (example). Can usually also be used for winter heating. The only one on this list that requires professional & permanent installation.
2. Portable split aircon (example). Uncommon.
3. Twin-hose portable aircon. Uncommon.
4. Single-hose portable aircon (example). Widespread but noisy and not particularly efficient.
5. Evaporative cooling, aka "swamp coolers". Most effective in dry heat, useless when the humidity is high.

The first item on that list involves holes in the building and external units bolted to the wall. Your position as a tenant rules those out.

I'd suggest the second one - a portable split - is possibly your best option. I've got one and have a thread with my experiences. The external unit can be "hung" on a bracket outside a window; you'll see a photo of mine on page 4 of that thread. This does assume that you have a suitable window, and it's easier to install if you've got access from outdoors; not too hard with a ground- or first-floor flat, less simple with a twelfth-floor one!

Portable splits were rather hard to find, even before this summer, and I don't know if stock levels have returned to normal yet.

If you don't like the idea of a portable split, you'll probably end up with a hose-type aircon. Twin hose units are more efficient (for reasons that are explained in this video) but are pretty much impossible to find in the UK. It's possible to modify a single-hose aircon to make it into a twin-hose, if you're moderately handy.

I said I'd explain why that water-cooled aircon isn't a great idea, so here goes.

Firstly, it's £3000. That's 10x the price of a basic single-hose portable and 4x the price of a portable split.

Secondly, it dumps its waste heat to water. The data sheet here says it uses 149 litres of water an hour. I don't know how much your water company charges for water, but mine charges me £2.75 a cubic metre to supply it, and another £1.55 a cubic metre to take it away again. That's £4.30 a cubic metre all told, which means 149 litres will cost 64p.

That might not seem a huge amount but (for comparison) the 680 watts of electricity that it draws will only cost 17p an hour. The water costs ~4x as much as the electricity does, for a total running cost of 81p/hour.

So you're paying 4x to 10x as much to buy it, then it costs 5x as much to run. That doesn't make much sense to me.

Albermarle

 The data sheet here says it uses 149 litres of water an hour.

With water being a short resource that is a pretty environmentally ( and costly) unfriendly option.

The average person in the UK uses 149 litres of water per day, although the target is to use less than 100.

ComicGeek

Just an alternative that I've never seen anyone mention on here before. Doesn't have to be 149 l/hr of potable water sent straight to the drain - I've used them for a house with closed loop connected to a rainwater and grewater collection tank, and no potable water used. People are always stating on these threads that you have to have an external unit or a hose - but that's not the case.

I saw them priced at £1k 6 months ago - all air con equipment is currently expensive and in limited stock still. Just wait a couple of months until everyone forgets what hot feels like.