Portable air con for surplus

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 😂

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

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.

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.

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.

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

That one certainly says it requires an engineer.

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?

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.

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.

Maybe, we've no mechanical ventilation and our house is definitely suffering when there isn't a breeze to circulate air

EDIT: I should probably say the occupants are suffering, the building itself is fine

Yes, internal wall insulated plasterboard. Easier to heat in the Winter and less heat off it in the Summer. The South and E/W facing walls weren't treated the same way, they were left exposed so that we had some thermal mass, but the windows within them were upgraded from double to triple glazed.

It can - and there are trade-off's. 👍️

That looks reasonable for the price. This one, €410? Blyss A018I-12CH Reversible Air Conditioner 12,000BTU - Screwfix

I'm deffo anti aircon generally as think it's fine most of the time in Ireland without it. But sleeping in this weather when you can't open windows sucks (living beside a main road)