Aircon unit suggestions

pbartlett

thanks - yes i think the key is you must seal it in, otherwise the hot air will get only so far up the chimney before cooling and falling back again, possibly condensing moisture as it cools.

CoastingHatbox

The irony in using more energy to deal with the effects of our overuse of energy.

tempus_fugit

We bought one from Argos a couple of years ago as we are getting ever hotter summers now and sometimes the bedroom is too hot to sleep in. It’s a Challenge 7000 BTU unit and does our bedroom fine (about 11 sq metres). You need to look at the size of the room and the BTU of the unit - 4 sq metres is quite small, do you mean 4m x 4m, so 16 sq metres? Oh, and it cost exactly £350 two years ago, so not sure of the price now.

It has a reasonable length of hose and I just stick it out of the window with it open just enough for the hose and shut the curtains over it. Maybe not 100% efficient but it works fine for us. At the moment it is getting a room at about 24 degrees down to 20-21 in about half an hour.

Any proper aircon unit will be noisy though, much noisier even than two fans, so it’s not ideal to leave on overnight. I use ours to cool the room down before going to bed, then 1 or 2 fans (depending on how warm it is) to circulate the cooler air while sleeping. Of course the air will heat up again overnight but it works for providing enough comfort to get off to sleep and for a fair part of the night. At the moment I couldn’t live without it.

collinsca

tempus_fugit said:

We bought one from Argos a couple of years ago as we are getting ever hotter summers now and sometimes the bedroom is too hot to sleep in. It’s a Challenge 7000 BTU unit and does our bedroom fine (about 11 sq metres). You need to look at the size of the room and the BTU of the unit - 4 sq metres is quite small, do you mean 4m x 4m, so 16 sq metres? Oh, and it cost exactly £350 two years ago, so not sure of the price now.

It has a reasonable length of hose and I just stick it out of the window with it open just enough for the hose and shut the curtains over it. Maybe not 100% efficient but it works fine for us. At the moment it is getting a room at about 24 degrees down to 20-21 in about half an hour.

Any proper aircon unit will be noisy though, much noisier even than two fans, so it’s not ideal to leave on overnight. I use ours to cool the room down before going to bed, then 1 or 2 fans (depending on how warm it is) to circulate the cooler air while sleeping. Of course the air will heat up again overnight but it works for providing enough comfort to get off to sleep and for a fair part of the night. At the moment I couldn’t live without it.

Thanks for commenting.

Ah yes oops, 4 by 4! so 16sq metres!

I've just looked yours up, there is one on ebay "new>other" for £270. Volume wise yours is 63db.  The one recommended earlier on this thread is "less than 50db". I appreciate even that is too loud for some to sleep. so your suggestion is a very good one (!) and we can of course use it during the day and accept the noise.

Ok, so 3 degrees it lowers it by. If i'm honest, i was perhaps over optimistic; i thought a unit would reduce the temp by more. How about if you left it an hour, would it be much more or still 3-4 degrees less?

So you would say it works well just putting the hose out the window? elsewhere ive been advised to get a window seal e,g, https://www.amazon.co.uk/COVVY-Universal-Portable-Conditioner-Conditioning/dp/B08CVB6Q2D/ref=sr_1_9?dchild=1&keywords=VELCRO+WINDOW+AIR+CONDITIONER&qid=1626965537&sr=8-9

Thanks again 

tempus_fugit

collinsca said:

tempus_fugit said:

We bought one from Argos a couple of years ago as we are getting ever hotter summers now and sometimes the bedroom is too hot to sleep in. It’s a Challenge 7000 BTU unit and does our bedroom fine (about 11 sq metres). You need to look at the size of the room and the BTU of the unit - 4 sq metres is quite small, do you mean 4m x 4m, so 16 sq metres? Oh, and it cost exactly £350 two years ago, so not sure of the price now.

It has a reasonable length of hose and I just stick it out of the window with it open just enough for the hose and shut the curtains over it. Maybe not 100% efficient but it works fine for us. At the moment it is getting a room at about 24 degrees down to 20-21 in about half an hour.

Any proper aircon unit will be noisy though, much noisier even than two fans, so it’s not ideal to leave on overnight. I use ours to cool the room down before going to bed, then 1 or 2 fans (depending on how warm it is) to circulate the cooler air while sleeping. Of course the air will heat up again overnight but it works for providing enough comfort to get off to sleep and for a fair part of the night. At the moment I couldn’t live without it.

Thanks for commenting.

Ah yes oops, 4 by 4! so 16sq metres!

I've just looked yours up, there is one on ebay "new>other" for £270. Volume wise yours is 63db.  The one recommended earlier on this thread is "less than 50db". I appreciate even that is too loud for some to sleep. so your suggestion is a very good one (!) and we can of course use it during the day and accept the noise.

Ok, so 3 degrees it lowers it by. If i'm honest, i was perhaps over optimistic; i thought a unit would reduce the temp by more. How about if you left it an hour, would it be much more or still 3-4 degrees less?

So you would say it works well just putting the hose out the window? elsewhere ive been advised to get a window seal e,g, https://www.amazon.co.uk/COVVY-Universal-Portable-Conditioner-Conditioning/dp/B08CVB6Q2D/ref=sr_1_9?dchild=1&keywords=VELCRO+WINDOW+AIR+CONDITIONER&qid=1626965537&sr=8-9

Thanks again 

Yes, the temperature drop is after about half an hour. It would probably drop by more if I left it on longer. Plus I have it set to 19 degrees, so I guess it would go quicker if I set it to a lower temperature.

It’s best to use a window seal, yes. But my windows aren’t really suited to it so I just use the lazy option, which works for me. It could be that the temperature would drop more quickly and efficiently if I did use a window seal (which would require me to completely replace the current window), so that may be an option for you. All I can say is that it lowers the temperature (and reduces humidity) enough to make the room a bit more bearable for a while on the warmest nights. Your mileage may vary. 😉

Jumblebumble

collinsca said:

Jumblebumble said:

collinsca said:

Any advice on models from anyone who has one and can recommend appreciated!

https://www.climachill.co.uk/product/pac12h-kyd32-12000btu-portable-air-conditioner-cool-heat/
We have used one for the past year and it has been great
Note it is a heat pump as well which is ideal for my garden office  in winter

Thanks so much - that looks ideal with the extra long hose!

Can you please advise..
-How loud is it, do you have problems sleeping due to the noise?
-What size rooms do you find this effective in?
-Do you have to seal off the window, or can you leave the window partially open?

Thanks again

It is on the noisy side so sleep might be difficult
The Cabin is 4 *5 meters
The hose goes out through a 150mm Hole drilled in the cabin wall
the issue is a quiet wall mounted one will cost c6 times the price I should think

knightstyle

can someone explain how these work when they say to seal the room with a window seal then put a single exhaust tube outside?  So where does the unit get the air supply from in order to send the warm air down the tube? Surely you need a supply of air, probably warm, into the room?
Commercial units I have worked on have external air ducts into and out from the condenser, the room air is recirculated through the evaporator with a small, 10% fresh air supply to keep oxygen levels OK.

collinsca

knightstyle said:

can someone explain how these work when they say to seal the room with a window seal then put a single exhaust tube outside?  So where does the unit get the air supply from in order to send the warm air down the tube? Surely you need a supply of air, probably warm, into the room?
Commercial units I have worked on have external air ducts into and out from the condenser, the room air is recirculated through the evaporator with a small, 10% fresh air supply to keep oxygen levels OK.

The hose goes outside the window to bring the air in.
It is possible to buy kits to seal the window so that only the hose is exposed to the outside.

coffeehound

Kightstyle is right, the hose carries hot air out, so you would need to allow some outdoor air to come in to the room somewhere so it can work.  Perhaps a landing window open a bit if you use a window seal for the hose.  It used to be possible to buy ones with two hoses -- air in and air out, but I'm not sure if they are still available.

For your room size, it looks that 9,000 BTU is recommended [here] other sources suggest 8,000 would be enough.  It's best not to use too powerful a unit, or it will be cycling on and off too frequently.

jamesd

knightstyle said:

can someone explain how these work when they say to seal the room with a window seal then put a single exhaust tube outside?  So where does the unit get the air supply from in order to send the warm air down the tube? Surely you need a supply of air, probably warm, into the room?
Commercial units I have worked on have external air ducts into and out from the condenser, the room air is recirculated through the evaporator with a small, 10% fresh air supply to keep oxygen levels OK.

The dual hose units have an intake hose for outside air to cool the condenser coils and evaporate the moisture that they condense. Less efficient one hose units use cooled air from the room as their intake. Both vent the heated and humidified air from their condenser to the outside, A chimney can be used for the vent hose only, a dual hose unit needs an air supply.

12,000 BTU is way oversized for a 4m by 4m room. That's what I used in New York to jeep a roughly 5m by 5m room at 78 degrees (25C) with outside temperatures up to 105 degrees (40C) and extra heat input from a flat roof. Something like 6,000 maybe 8,000 BTU would be plenty for a 16 square meter room in the UK.

Be wary of thinking that more is better. It isn't. If you oversize you can get ice forming on the coils and insufficient dehumidification as well as short cycling. It's a recipe for a clammy (damp) room instead of a comfortable one because the AC hits the temperature setting before it's done dehumidifying properly. You'll find that some calculators oversize units, particularly those without window area inputs or those assuming one of the US regions as the external temperature range.

The practical problem may be even finding a unit of 8k BTU or smaller.

Don't set an air conditioner thermostat to a lower temperature than you want to try to get it to cool faster. It can't cool faster than its heat exchanger design allows. You can speed your comfort up by adding fans to move air from hot corners you might be lying or sitting in towards the AC but if you get the output right it should take care of the circulation for you. Good circulation is probably best done by directing the cool air towards the top of an inside wall opposite the AC but experiment a bit if you're in a corner or next to an outside wall a lot.