Portable air con for surplus

harderthanf

Thinking of a portable air con unit for the summer months. Mostly to use any excess I have to cool my office (with the help of home assistant). Has anybody done similar? If so, any recommendations for units? There are so many

As an aside, I am in Orlando for the last weeks. It's unbelievable how little domestic solar they have here. Practically zero.

Jonathan

Was thinking along similar lines and bought a second hand 9000BTU unit in new condition off adverts for €140 a few weeks ago.

SD_DRACULA

I looked at this as well but most things I found required a horrible hose type thing to go out the window.

What type is that @Jonathan

Nelbert

Proper air con needs to expel the heat somewhere... If you don't see a house it's just a fan (usually).

JimmyVik

Get one of those wall mounted ones. No issues with heat transfer through the hose or gaps around to make it inefficient.

Can be used a heater too.

https://www.wholesaleheaters.co.uk/powrmatic-vision-3-1dw-twin-duct-air-conditioner/

SD_DRACULA

Wouldn't mind going for one of these, get 3 rooms out of it but problem is finding someone who can fit it (correctly)

https://www.buyitdirect.ie/p/multi-split-27000-btu-smartapp-wifi-inverter-wall-air-conditioner-with-3x-9000-btu-indoor-units-to-a-single-outdoor-unit-iqool-3ms9k9k9k

Does both heat and cool.

harderthanf

https://www.boards.ie/discussion/comment/118855992#Comment_118855992

That is some price. Was looking for something a bit more cheap and cheerful!

I don't mind the hose, it's really just for a mid sized room.

Schorpio

I got one last year during the heat wave. This one to be precise. At the time I really struggled to find anywhere with units that were reasonably priced and would ship to Ireland. However, I was buying at the height of summer, so you might be in a better position now on that front.

Definitely worth it, imo. Max power draw for the unit I have is stated to be 1.1 kW, but it seemed to usually sit around 800 W. It's quite a small unit, but perfect for a single office/bedroom/etc. You will need to buy the window seals separately though.

harderthanf

Window seals? What are those!?

This comes with the hose, yeah?

Sleeper12

I had a portable AC unit a few years ago. I got it for the sitting room. Tried to use it 2 or 3 times but gave up. It was so noisy we couldn't watch the TV.

Got a mini split heat pump / AC last year. It's super quiet

Schorpio

https://www.boards.ie/discussion/comment/118857800#Comment_118857800

Yes, comes with the hose, but that's no good if you're letting the ambient air back inside. The window seal is like a plastic-y material which attaches to your window with velcrow and you stick the hose out through it. It's just to try to keep the warm air out. Obviously it's not a perfect system, but it's good enough for a small/non-permanent solution.

On the noise front - the one I have has 2 power settings. It's quite noisy in the higher power setting, but I didn't have a problem with the lower setting. It's similar to the amount of noise produced by a dehumidifier.

The permanent solutions essentially have half of the machine located outside, which gives them a huge advantage in terms of noise and dealing with waste heat. The all-in-ones are never going to be able to complete with that, but on a hot day they still produce lovely cold air.

the_amazing_raisin

I really like this idea, found during the last few heat waves that the bedrooms got so hot it's almost impossible to sleep

Running the air con in a low power mode during the day might stop the heat building up so much. And with solar it seems like a great idea

If I ever replace the heat pump I'm definitely getting one that can do cooling as well so I can do this on a larger scale with solar

Tree

Do you need your house sealed/airtight for permanent/semi-permanent aircon like for a heat pump?

Sleeper12

Aircon will work fine in any house. The better insulation /airtightness, the easier it is to cool & keep cool.

SD_DRACULA

Looking into the possibility of adding a split system (or two) that can do both AC and heating, something similar to these: https://www.buyitdirect.ie/p/multi-split-27000-btu-smartapp-wifi-inverter-wall-air-conditioner-with-3x-9000-btu-indoor-units-to-a-single-outdoor-unit-iqool-3ms9k9k9k

Just wondering if anyone here has done something similar and can suggest a decent installer in the Dublin area

poker--addict

I have one of the portable units.

the hose out the window is a bit of a faff and I suspect adds significant inefficient and quick reheating of the area. Maybe hose into attic via vent in bathroom is an option.

alternatively with the summers seemingly getting warmer, and our house bakes with solar gain through windows, I am considering going all out and getting a few permanent air to air units. Pricey though.

poker--addict

Ok perhaps a misleading title.

Our house bakes in summer with solar gain particularly upstairs. Air con units would basically have no electricity costs now that solar in installed, so I am wondering has anyone installed air con?

it's rare in Ireland but summers do seem to be getting hotter, and a lot of new houses seem to be hard to cool too, and throw on the solar to power it for free and maybe this is a space which will grow?

Curious if DIY is an option for install?

graememk

https://www.boards.ie/discussion/comment/120668093#Comment_120668093

A Chimney for ones that still have them should work well. Shove the pipe up there. maybe an old towel to seal it up a bit.. hot air rises.

cnocbui

The average annual temperature in Ireland is about 10°C. It's why all those data centres set up shop here - free cooling. The annual average temperature in Sydney is about 20°C.

No, I do not think this is an area that will grow.

graememk

Average temperatures are misleading though.

But yes this area will grow. Just picked up a portable one, wont need it until july/aug. Plan is to blast it during the day and have it off at night when home.

But me Try and do it as cheap as I can, have plenty of power, so picked up a refurbished one for 360ish 12000BTU one from buyitdirect, We shall see how it goes for me.

Still not fully installed aircon, but should be enough to take the edge off.

poker--addict

Unfortunately my problem is upstairs so no chimney to shove pipe into.

i think it's 9000btu, so not the biggest but not small either. Like you say, running it during the day, off at night. But finding once off it's not long before temps up again, and I'm blaming the lack of air tightness with pipe out window setup... also surprising how little the air moves to the adjoining bedroom beside it.

Jonathan

https://www.boards.ie/discussion/comment/120668166#Comment_120668166

Hadn't considered chimney! I will try that next time.

The window adapters only work well for sash type windows (which I don't have) so hard to get a good seal as @poker--addict says.

DC999

https://www.boards.ie/discussion/comment/120668320#Comment_120668320

For us it's stored heat in the external red brick walls that travels internally. Sun travels around the house from morning to evening with nothing blocking it. House is all red brick - which 'sponges' up the sun.

Pumps out as radiant heat all night. Like an UFH when you don't want it :)

Bedrooms stay well into 20s at night during really hot spells. Beside a main road so can't open windows or no one can sleep. Windows open until bed time and temp climbs as soon as closed.

DC999

https://www.boards.ie/discussion/comment/120668166#Comment_120668166

Man, you think so differently. In a good way. You come up with ideas many wouldn't. Most of us have an unused chimney during summer and I never thought of it. Class!!

slave1

https://www.boards.ie/discussion/comment/120669017#Comment_120669017

If you want a cool bedroom you should not have the window opened during the day and have curtains/blinds pulled down to lower solar gain

DC999

https://www.boards.ie/discussion/comment/120669115#Comment_120669115

For us solar gain is not the big issue upstairs (sure, it can reallly heat rooms though). We've only a single small landing window on south side.

It's the 'thermal mass gain' of the whole external walls being cooked in the sun all day.

the_amazing_raisin

Would putting the vent pipe up through the attic hatch be an option? It's generally outside the insulated space and is probably well enough ventilated to remove the warm air being added

graememk

https://www.boards.ie/discussion/comment/120669262#Comment_120669262

Thought about that, the air out of them is usually humid too, (so you don't have to empty it) not sure what consequences that has though.

There is window kits for our normal hinged windows.. anyone for core drilling a vent through the block work? And seal it up in the winter?

I suppose also it could be assisted with fans to circulate the air through the house?

the_amazing_raisin

https://www.boards.ie/discussion/comment/120669367#Comment_120669367

Most houses these days have the high tech Irish ventilation system (big hole in wall with cheap plastic vent cover) so I guess you could use those if you have them?

That's probably what I'll end up doing, but it kind of fixes the air conditioner into one room which is a bit wasteful for the 1 week a year it's needed, and negates the portable bit

poker--addict

https://www.boards.ie/discussion/comment/120669367#Comment_120669367

Considering this option too, albeit hard to know ideal location, and then it's another hole in the winter. Part of me feels if going to effort of bursting holes in the wall then may as well just get a permanent air con unit which will be quieter and work better.

mine collects water seperate to hot air flow, so pumping into attic leaves me with no concerns about humidity on timber up there. However on a day with min airflow through attic that space will I imagine get extra warm, and in a way hinder cooling.

Schorpio

As someone who has had a single-hose portable unit for the past few years - I would say don't do it.

I'm not saying don't get any A/C, but just don't get a single hose units. Especially if you intend on using it in rooms you want to sleep in.

They are are loudest, and most inefficient A/C units you can get. Even at a lower-blow setting, you will still have the noise of the compressor circulating the refrigerant. It's much like a fridge, except louder.

Also, whilst the hot exhaust air goes through the hose and out the window; that air originates from inside. This is a problem for two reasons. Firstly, you are using electricity to cool the air in the room, only for some of the air (which you have used energy to cool) going straight back outside; and secondly, pumping air out of the room lowers the pressure within the room which then means that external air is sucked in.

As others have said, the only semi-good window seals are the ones which work on sash windows. If you have windows which hinge outwards, the seals are not very good at all (but better than nothing). I am looking into whether I can tie the unit into the room vent, but I need to try to get/make an adapter.

Better systems exist.

2 hose units suck in external air to dissipate the heat generated by the unit, which is much better as you aren't exhausting your cooled air, and you're not creating a pressure differential. These units seem to be fairly rare though.

You can also get split 'portable' units, which are like mini-versions of the installed A/C units. These keep all of the hot stuff (and some of the noisy components) outside, with just power and refrigerant lines connecting the two. These are expensive though.

Best is a permanent install - but this is more expensive again.

DC999

https://www.boards.ie/discussion/comment/120670120#Comment_120670120

Fair point with benefit of a temp air vent into the attic. Bear in mind with using an attic door (with a new large hole in it), you don’t wanna breathe in rock wool insulation fibers. Or minimise it.

I considered a giant fan in the attic door instead of air con. They do that in The States, or did back in the day pre air con. Forces all the hot air from house into the attic close to bedtime. Dirt cheap to run as it’s just a fan. They really work – fans are mad powerful and the size of the attic door so pushes a huge volume into it and pulls in cools night time air in the process (from windows open in the house).

But then I realised you don’t wanna breathe in rock wool insulation fibers. So that huge fan would ‘disturb’ the insulation which would come back through the door. And we’re breathe it for the whole duration we used the fan (the summer). I expect it would be somewhat similar with an aircon pipe. The dust crap from the attic would have to settle in that when it’s powered off. And maybe that’s minor and fine for people. Not suggesting people don’t consider it, just think if it causes other issue. That said I’d likely do it myself for the few hot nights it’s hard to sleep.

When our solar installer was here in the attic, he’s a really good mask to filter the air he breathed. He said it’s like he’s been smoking if he works in an attic without the mask, he just won’t do it. Tinternet tells me ‘Breathing in rock wool fibers can potentially be harmful to your health. When rock wool is disturbed or handled improperly, it can release small airborne fibers into the air. These fibers, if inhaled, can irritate the respiratory system and potentially cause health issues.’­ -  likely makes sense if you ever spent time moving stuff in an attic.

Would be mould in the insulation too from leaks at times, or from condensation from water pipes in winter maybe. Again, don’t wanna breathe that stuff in daily if you can. 

the_amazing_raisin

Somewhat OT, but I remember reading a review of an indoor heat pump water heater with an integrated tank.

I was very confused about the reviewer saying that had the exhaust going into the attic. I was wondering why you'd be dumping cold air into the attic in winter, then I realised it was in California where winter is a bedtime story to scare children 😂

A good fan is probably more than sufficient. I can't imagine too many houses needing air con in Ireland.

the_amazing_raisin

https://www.boards.ie/discussion/comment/120671341#Comment_120671341

The problem is these new A3 rated houses are pretty excellent at retaining heat. Great in winter when it's freezing out, not so ideal in summer

I'm also pretty sure the insulation has a radiant heat barrier (tin foil) on the inside, but not the outside. So it stops radiant heat escaping, but allows solar gains from the sun. Again, great for winter, not great in a heatwave since it effectively warms the house up

I agree that airflow helps a lot, had a few fans last summer which kept things tolerable in the heatwave

The main issue there is you need to keep the fans going through the night otherwise the heat builds up again. Also if the outside temp is 27C then you can't really magic it much cooler with a fan. Might knock a few celcius off but it'll still be extremely warm at night

I guess the idea with an air conditioner is to "store" cool air in the house during the day and stop the house becoming overheated while the sun is out

I don't think it'll work miracles however because you'd have to cool the entire house, otherwise you'll have warm air coming in from other rooms

graememk

I agree none of this is a need though, we're having good weather now but the evenings are still chilly and any heat build up in the day is lost through opening of windows.

Fans only counteract the skin effect and remove the boundary layer of insulating air, knock a few c off with air con, and then have a fan to circulate the air about too

I'll still be closing curtains etc when it gets really hot to try and keep the heat out when the next heat wave comes... I'm already in shorts in this weather. 😆

mustang68

I installed a mini-split in the garden office, I got it for the efficient heating (SEER 6.2), but it's free cooling in the summer (the office can get quite warm).

I made a few phone calls to get quotes in Ireland, but most were commercial installers or wanted stupid amounts of money to do it, after a bit of research I opted to do it myself.

You can get a kit that comes with everything you need, including (this is the important part) pre vacuumed lines - if you don't get these you'll need to have someone out to pull a vacuum, or get a pump to do it yourself (the units all come with refrigerant preloaded). All in the kit was about 1000 shipped on a pallet. Mitsubishi 2,5kw. It needed a hole though the wall for the lines, drain and power connector - about 5cm - that was the hardest part.

It's really quiet and can run at a very low power, highly recommended.

DC999

https://www.boards.ie/discussion/comment/120682024#Comment_120682024

Fair play. I’d deffo be interested in that. Could have it tipping away heating on low wattage from solar in winter. Would you consider yourself an average DIYer, or a ninja? Wondering in terms of the level of work to install it.

Could u pop in the link for the model you got?

Is there any way to see the pressure of the gas in the lines now it’s installed? Afaik if there’s a leak it’s hard to know without an actual pressure gauge (similar to the one on a gas boiler for water pressure). And performance goes to crap, but it’s hard to tell. 

mustang68

https://www.boards.ie/discussion/comment/120682563#Comment_120682563

I'm an average DIYer, was nervous going into it, but the reality is that that when you go outside Ireland to warmer climates you see mini-splits everywhere as DIY installs, so they are designed to be easy install. In the US there is a brand called Mr Cool, that uses similar connections, lots of youtube videos on how to do them that got me looking at this as an option. Hardest part was putting a hole in the wall, the drain must be facing down so you have to keep that in mind

This was the kit I got on ebay, you can specify mounts and the length of connections between the units, came with instructions. Unit works well, but the Mitsubishi App isn't going to win awards for innovation.

There isn't a pressure gauge, but there are a bunch of connectors that I'm sure you could attach to if needs be. I'll be treating it like my car AC, if the performance drops then I'll see what the issue is.

When running it tends to run low and slow, only taking a 200Ws or so, I've only had it a few months so your mileage may vary.

micks_address

https://www.boards.ie/discussion/comment/120682794#Comment_120682794

can i ask you - can you have the heat pump on the back of the house and run the pipes through the attic and down to unit on the front of the house? we have a 4 bed semi in dublin and it does get warm upstairs.. last summer was over 28 degrees inside and that was with black out blinds closed in the rooms, and basins of ice sitting in front of a pretty large honeywell fan..

mustang68

https://www.boards.ie/discussion/comment/120687020#Comment_120687020

You can have the refrigerant pipes run any direction, but the drain pipe cannot run up - the ice buildup on the inside unit melts and the water has to drain (it's not pumped), if the pipe runs uphill the unit will leak. The drain pipe doesn't have to go back to the outside unit, it just needs a drain somewhere.

poker--addict

this DIY option is extremely interesting. Presumably there is some DIY units with a few splits. I would ideally want 3 or 4.

DC999

https://www.boards.ie/discussion/comment/120689763#Comment_120689763

Think SD_dracula posted one before that could take up to 3 indoor units / splits. Can't recall if that was DIY or not. With a few splits the pipework becomes longer with more connections that you would need to make yourself to fit your house. And there's pressurised gas in it, so more chance of leaks. Might have max distances between splits back to the outdoor unit on DIY units. So the DIY element gets harder I guess.

But I'm deffo in the camp of not ruling out a DIY myself. If it came down to a costly home heatpump V a cheaper but lower performing COP on an air to air mini splits... Well, it's worth some number crunching

People say the downside is it can actually feel colder as the air is blowing over you. That cools us down of course (even when hot air). But I reckon I could live with that, just mind where you fit it so not over your head when sitting

con747

https://www.boards.ie/discussion/comment/120689763#Comment_120689763

These were posted before. https://www.buyitdirect.ie/p/multi-split-27000-btu-smartapp-wifi-inverter-wall-air-conditioner-with-3x-9000-btu-indoor-units-to-a-single-outdoor-unit-iqool-3ms9k9k9k##reviews

poker--addict

That one certainly says it requires an engineer.

Stealthirl

I got a portable one a few years ago as im a night worker and sleep in a southern facing room, regularly seen +25c on hotter days and +30 on rare occasions.

I made up a plug for the window with 10mm PIR cut an angle on one side and velcro sticky tape on the frame to hold it in place. It's not airtight, but was the best i could come up with. I have a 125mm hole in that for the extract, and the flexi hose is an insulated one to reduce thermal gains. I don't mind the noise as it drowns out lawnmowers, kids, dogs etc.

If noise of the unit would be an issue, the mini split is perfect. I might get on eventually, but at the time they were 2 or 3 times the price of the portable unit. Normally it draws about 9-1100w when cooling and about 500w when it's just the fan

micks_address

right last night was another reminder i need to do something about this... re the refrigerant in the unit linked on ebay.. that all comes pre filled?

10-10-20

https://www.boards.ie/discussion/comment/120687020#Comment_120687020

As far as I recall the pre-filled units can't be extended without having an AC engineer visit (or you obtain a vacuum pump and refrigerant) - you can only work with the pipe which is supplied as the pressure is already set by virtue of the preset length. So yes you can do what you describe, but also factor in the losses over a long pipe run as these will add up.

circadian

https://www.boards.ie/discussion/comment/120671389#Comment_120671389

I don't think this is the case. I've done a full retrofit of my home which would have been cold in winter and too hot in the summer. Now it's great in winter and so far, even with the rear being south facing it's not uncomfortable, open the windows first thing then the house stays at a nice temp. It could be the mechanical ventilation at play but in general the insulation should prevent massive swings in temp.

SD_DRACULA

https://www.boards.ie/discussion/comment/120689444#Comment_120689444

You can get tiny pumps for this so you can go up too, they usually sit in the elbow trunking of the indoor cassette, so they can be run via the attic

DownByTheGarden

I got a vision 3.1. Great for AC and even better for heating in the winter. Just bore a couple of holes and mount it on an outside wall in the room you want heated/cooled. Ours was the kitchen. I was thinking of getting another one for heating the sitting room in the winter too because they are dirt cheap to run.