Sorry, couldn't resist:

Anyway, on a serious note, lowering the ambient temperature is the only way i.e. air con. Blowing air with a fan only works for humans because transpiration creates the illusion of moving air feeling cool.

Air conditioning is not cheap, but it's the best solution. A proper AC installations is expensive, and involves making some holes into and hanging things on the outside of the building.

Portable ACs are cheaper, but be careful about their working modes. Usually they can work with or without "installation". "Instalation" means that you took a tube from the AC unit to the outside (via a hole in a glass, a partially open window or those things). If you do this, it will work better. If you are not willing to do that installation, the AC unit will need some water and surely "pee" (=produce some water from condensation), so you'll have to keep an eye on it and empty some water reservoir when it gets full.

A fan with ice will cool the room slightly better (placebo?) than a fan without ice, but those ice will produce some humidity (I don't know how much). I've seen some "portable ACs" that are only fans with a reservoir for ice on top... I wouldn't trust them.

A fan without ice won't cool the room, instead it will slowly warm it (because you're only moving air and the motor is producing heat). It feels that the room is slightly cooler, but that's it. BTW, my current cooling installation is a 60W fan 😉

So, if you need to keep temperature control, go into AC. If you own your house, put a proper installation; else get a portable AC and try to do the "installation". If you need only get human beings comfy, you can use fans. Most computers will run fine (or will throttle down) even without cooling, but server stuff will surely need temperature control.

Zup has provided a very good summary of each type.
Just to add to this. What is also important is to determine the air-con size (better known as the BTU or British Thermal Unit size) that you require.
There are calculators online, but based on your description, I think that a 9000 BTU unit will be sufficient.

Some portable and most wall (fixed) mounted units can actualy cool down in the summer and warm (heat) up during the winter. Although, based on the time I spent in the UK (particularly London), practically all houses/flats have central heating.
Just take note, the higher the BTU rating, the more power it draws and the higher your electricity bill (depending on how long you run the unit).

Here where I stay in South Africa, our summers tend to get very hot and to make matter worse, the humidity can also sometimes be high. So, air-con is very much desirable.

I initially tried out a portable 12000 BTU unit for our bedroom, but had trouble getting rid of the hot air that the unit was generating via the tube (the best solution for these type of portable units is to actually make a round hole in the ceiling and attach the tube to a bracket so that the hot air can escape inside the roof).
Eventually, I sold the portable unit and installed proper wall mounted units (it is expensive, but if you live where I stay, then it's worth it).

But, in the UK, a portable unit should work fine, provided you can find an effective way to let the hot air out that the unit is generating.
Other methods, in my opinion, are just not that effective.

I usually just open the windows and close the blinds. One of the tricks are to keep the sun out and air flowing.

Are you worried about your personal comfort or your computer(s) overheating?

Well let me tell you how we do it without AC here in texas.

http://www.instructables.com/id/5-Gallon-Buck … ir-Conditioner/

This really works, had to do it in my place when the AC broke, kept the bedroom cool over the weekend until the apartment maintenance man could get it fixed.

To give you an idea, that weekend it was 104F(40C) outside, and our apartment thermostat was telling us it was 90F(36.6C) inside, it gets hot here in Texas.

Yes it works, we built 3 of them 🤣

Kerr Avon wrote:

What's the best (cheap) way to cool a room on a really hot day? I'm in England, so such days aren't common, but that means that […]
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What's the best (cheap) way to cool a room on a really hot day? I'm in England, so such days aren't common, but that means that the houses and flats in England aren't built for hot days, so there isn't much air flow from room to room. And where I'm staying at the moment, my bedroom is a small box room, so it's too small for a cooling system that takes up much space.

The options I know of, in descending order of effectiveness, are:

Air conditioning,
A fan that creates cold air by making ice and blowing the ice over it,
A fan that just blows air.

The house doesn't have air conditioning, of course, but you can buy portable units (I've heard). How are these, and are they too noisy or have other flaws? And don't they all need an output pipe to a windows to pump out the heat?

How good are the ice/fan machines? Are there any goods ones smaller than the standalone Dalek type ones?

Failing that, what very good fans are there?

Or are there any other good methods to cool a room? And if you recommend any particular model of fan/cooler/etc, then please try for something in Argos, Currys, or Tesco, as they have branches here.

Come to the southern US and you will melt like a tub of ice cream on a hot day, bad days in the states basically equals 40 to 50c in some spots but official temps are always lower.

I've had a portable AC before. Hose goes out the window, they work well, but the compressor being inside, they make quite some noise 😀

Can't think of anything better though that can be easily packed away and moved like it.

Do you want it cheap? Close the curtains.

Do you want it good? Buy a split AC.

I had one of these in college that got me through an incredibly hot fall and spring with no AC:

https://www.amazon.com/Honeywell-HT-908-Turbo … words=turbo+fan

Really moves a lot of air. Combine that with a damp sheet when you sleep and that would most likely keep you cool.

Ideally, though, the most effective will be AC, either a window unit or a portable unit that has a pipe/hose to the outside (usually has some sort of baffle you put in the window and hook the hose to).

But for sheer cheapness you can't beat one of those fans.

I'm guessing window unit air conditioners are not that common in the UK. The other problem is if you don't have double or single hung windows to put one in, the vertical units for sliders and casements tend to be much more expensive. They are much more efficient to run then those stupid portable units with the hose.

The UK isn't usually warm enough to need AC, and AC is expensive, so almost no-one bothers.

For the part of the year it's suitably warm, it's usually effective enough to open some windows and wear less clothes.

There was one, maybe two days this week where it was too warm to sleep with a duvet. Then it rained.. (I'm in the North, near the countryside, the temperature is a little lower than elsewhere)

The ice bucket method is interesting, though. How long does it last? Obviously it'll be necessary to keep rotating the popsicles as they warm up.

It isn't that expensive to occasionally run a window unit (electricity isn't cheap in the Northeast US, a 5000btu window unit costs about $99-120US to buy new). It doesn't get nearly as hot around here compared to the southern US, but it can get pretty muggy and humid. Its not uncommon to run A/C at night here when its down in the high 60s-low 70s F (20-23 C).

NJRoadfan wrote:

It isn't that expensive to occasionally run a window unit (electricity isn't cheap in the Northeast US, a 5000btu window unit costs about $99-120US to buy new). It doesn't get nearly as hot around here compared to the southern US, but it can get pretty muggy and humid. Its not uncommon to run A/C at night here when its down in the high 60s-low 70s F (20-23 C).

That's a cool breeze by our standards: It isn't uncommon to hit 40-45ºC during the day and 32ºC+ during nights. 🤣

Errius wrote:

Are you worried about your personal comfort or your computer(s) overheating?

Just me. I have a bigger room with my PC desk, bookcases etc, but I like the box room for a bedroom as I can have my large TV, consoles, second PC plugged into the TV for gaming and media, etc.

When I finally get a job that doesn't involve changing location every so often (I do agency based IT, I'll be so glad when I find a good, permanent position) then I'll look at a permanent, built into the wall/Window air conditioning for whatever house or flat I settle in (depending on the price of AC installations, of course). But for now, that's not an option.

Plus being in England, being too hot isn't a long term or frequent problem, if you totalled it up, it would probably be less than one month a year (albeit spread out across March to November, dotted amongst the rainy or cold days), it's not nearly so bad as people in other countries have it (or not nearly as good, depending on your point of view!).

Snayperskaya wrote:

That's a cool breeze by our standards: It isn't uncommon to hit 40-45ºC during the day and 32ºC+ during nights. 🤣

I spoke too soon, its about 80F/26.5C outside right now (0130 hours) and humid.

Snayperskaya wrote:

It isn't uncommon to hit 40-45ºC during the day and 32ºC+ during nights. 🤣

And people still live there? I would die at those temperatures. 😵

Just pretend you're on a beach resort somewhere and strip down to shorts. Keeping your hardware cool is more difficult. I recently added a stronger case fan to my main rig, only to find that it interferes with the CPU fan (they blow in opposite directions) so I now have a hotter computer...