Split Air con

[uncle_rufus]

We're putting one big unit on the top floor landing (3 storey) and a smaller unit in our kitchen/diner/family room (which is a large room making up most of the ground floor) with the intention of helping to keep the whole house a bit cooler (in particular to two bedrooms on the top floor)

 

[Matthew.M]

So my first one is in, no issues. It only took them a couple of hours. The inverter is on foam feet on the garage roof and the pipe run is super short to the wall unit, through a 70mm hole. It's at the top of the stairs pointing into the master bedroom.

It's a Mitsubishi Heavy Industries 3.5kw cooling / 4kw heat unit.

Very impressed by how quiet it is. Completely astounded by how much heat it kicks out in heating mode, unbelievable.

The original plan was to have this unit upstairs to take the edge off the bedrooms and another unit downstairs in the living room. When it's hot it's really difficult to keep the upstairs of our house cool. Having had a play with this one today I'm going to hold off on the whole planning permission issue/additional downstairs unit until I've had experience using this one on a hot day. Within 30mins of it being on upstairs is like a fridge and you start feeling it downstairs, and that's on eco mode. Albeit, it wasn't exactly a hot sunny day today. So very interested to see how it performs when things warm up.

 

[b0rn2sk8]

Has anyone got a ceiling mounted unit or ducted loft based units?

I’d like air con but it doesn’t matter which way you look at it the standard wall mounted units are ugly and I’m fairly sure it would be vetoed on the grounds of ugliness in my household.

 

[HungryHippos]

My Aircon is being installed next week - Daikin system powering 2 internal units; fingers crossed it does the job!

Also interested in what the units are and what the price came to? My figures are further up.

So my first one is in, no issues.

Looks good! to be honest for the planning stuff, you can also just apply for it retrospectively after it's done. If no one moans within 4 years you're golden I think.

 

[fobose]

Has anyone got a ceiling mounted unit or ducted loft based units?

I’d like air con but it doesn’t matter which way you look at it the standard wall mounted units are ugly and I’m fairly sure it would be vetoed on the grounds of ugliness in my household.

I've already got my next house planned to have ducted lol, unless I end up in 3 story house again. It does make sense for the discrete look. Personally I do not mind my current units as they look reasonably stylish (IMO). It made sense in my current house to go for this type.

The original plan was to have this unit upstairs to take the edge off the bedrooms and another unit downstairs in the living room. When it's hot it's really difficult to keep the upstairs of our house cool. Having had a play with this one today I'm going to hold off on the whole planning permission issue/additional downstairs unit until I've had experience using this one on a hot day. Within 30mins of it being on upstairs is like a fridge and you start feeling it downstairs, and that's on eco mode. Albeit, it wasn't exactly a hot sunny day today. So very interested to see how it performs when things warm up.

A very simple and neat install! I am not a fan of the style of the internal unit, but it is in your hall way in a location that you won't be looking at very often so a complete none issue. I will be keen to know how it does keeping the bedrooms cool in the summer, hopefully you master bedroom stays cool at least if it is blowing in to it.

 

[uncle_rufus]

Also interested in what the units are and what the price came to? My figures are further up.

Hoping this isn't going to make me feel/realise I'm being ripped off! Price is around about £3k, the units are:

5kw Daikin 2MXM50M9 is the external unit

Inside a 5kw FTXM50M upstairs and 2.5kw FTXM25M downstairs - both have the wifi controller stuff etc.

I know what you're thinking... 5 + 2.5kw /= 5kw... wtf?! I asked the same question. So we will be able to run the upstairs one absolutely flat out if we want to, when the downstairs one is off, but when both are on they will have to share capacity a little bit (won't be able to run them both at 100%). On the one hand it seems a weird choice but really we are most likely to use the downstairs one a lot during the day but less in the evening (once we've had dinner etc. we tend to move upstairs for the remainder of the night - our lounge is on the middle floor too) and not at all overnight

We're end terrace and the one on the top floor is being mounted on the non-external wall, so the ducting is going to route straight up into the loft and across to the other end, then right back down to ground level (external unit on the driveway) whereas the one on the groundfloor is on the external wall so can go straight through and down

Originally they were going to run a spur off of an existing circuit as it would have been easier than making a dedicated connection from the fusebox, but anticipating that we will end up wanting a car charger on the drive someday as well we are planning to get the electrician to run us a pair of suitable cables round to the drive properly (and just leave the "spare" one unconnected or something for using later). Figured we might as well, save a job later

 

[fobose]

I know what you're thinking... 5 + 2.5kw /= 5kw... wtf?! I asked the same question.

You might think that but once the area has reached the set temperature, it only has to maintain it, so will probably only be using 5-10% to keep on top of it. The rest will go to the other unit and then the same thing will happen with that. If you had a 7.5kw outside unit, it would not be very efficient. My setup is similar with 3x 2.5kw internal units and a 5.5kw external.

I assume you will need a condense pump for your top floor unit if its going straight up in the loft? Probably not a problem if in the hall way as you wont hear the noise in you bedrooms.

P.S I think you price is pretty good.

 

[YoungBlood]

So my first one is in, no issues. It only took them a couple of hours. The inverter is on foam feet on the garage roof and the pipe run is super short to the wall unit, through a 70mm hole. It's at the top of the stairs pointing into the master bedroom.

It's a Mitsubishi Heavy Industries 3.5kw cooling / 4kw heat unit.

Very impressed by how quiet it is. Completely astounded by how much heat it kicks out in heating mode, unbelievable.

The original plan was to have this unit upstairs to take the edge off the bedrooms and another unit downstairs in the living room. When it's hot it's really difficult to keep the upstairs of our house cool. Having had a play with this one today I'm going to hold off on the whole planning permission issue/additional downstairs unit until I've had experience using this one on a hot day. Within 30mins of it being on upstairs is like a fridge and you start feeling it downstairs, and that's on eco mode. Albeit, it wasn't exactly a hot sunny day today. So very interested to see how it performs when things warm up.

Mine is in the same location - works a treat. But! your landing will reach the set temp in minutes and throttle the unit down, leaving your master room too warm or too hot as it will take the temperature from where the indoor unit is located.

So make sure you use the "follow me" function on the remote and place it in the master bedroom pointing towards the unit.
I'm sure you knew this but just in case it will then use the temperature of where the remote is rather than he temperature of the landing.

How is the outdoor unit fixed to the roof? is it simply resting, or did they bolt it into the roof?

 

[Matthew.M]

A very simple and neat install! I am not a fan of the style of the internal unit, but it is in your hall way in a location that you won't be looking at very often so a complete none issue. I will be keen to know how it does keeping the bedrooms cool in the summer, hopefully you master bedroom stays cool at least if it is blowing in to it.

Only day 1, but we don’t notice it. Agreed we wouldn’t want this in a bedroom or living area but it’s at the back of the stairs so you only see if you look up. It was also very cheap. The fitter said it was the simplest possible install as we had power, didn’t need a condensate pump, and we’ve gone for a more basic unit. Installed, the bill was 3 figures so a lot cheaper than some of the systems quoted here.

How is the outdoor unit fixed to the roof? is it simply resting, or did they bolt it into the roof?

It’s resting as far as I know. The feet feel like the material you find on the ground in children's play areas. The unit weighs 30kg+ so I don’t imagine it’s going to move anywhere in a hurry!

 

[uncle_rufus]

You might think that but once the area has reached the set temperature, it only has to maintain it, so will probably only be using 5-10% to keep on top of it. The rest will go to the other unit and then the same thing will happen with that. If you had a 7.5kw outside unit, it would not be very efficient. My setup is similar with 3x 2.5kw internal units and a 5.5kw external.

I assume you will need a condense pump for your top floor unit if its going straight up in the loft? Probably not a problem if in the hall way as you wont hear the noise in you bedrooms.

P.S I think you price is pretty good.

Cheers! That makes sense, I'm not too worried - the chap from the local company fitting it stopped by and really came across very well, seemed to know what he was talking about so I'm happy to go with whatever he suggests. Not sure about the condense pump? Is that because it's having to move coolant upwards from the unit? (to be fair I think it will only need to travel upwards about 1ft from the unit, if that, before it goes horizontal to travel across to the other side - the top floor is like a half-attic type thing, so as soon as it goes through the ceiling it'll be by the rafters in the loftspace). He said none of the units should be noisy so fingers crossed!

 

[RJC]

The condensate pump will be for moving the water out of the unit - the pump your mentioning is a liquid pump used for liquid amplification in larger units!

I have my unit in the hall way and use a floor fan to help direct the air into my bedroom.

At some point I am looking to install one in my dining room and this will help cool the living room.

 

[HungryHippos]

Hoping this isn't going to make me feel/realise I'm being ripped off! Price is around about £3k, the units are:

5kw Daikin 2MXM50M9 is the external unit

Inside a 5kw FTXM50M upstairs and 2.5kw FTXM25M downstairs - both have the wifi controller stuff etc.

Nope that sounds pretty reasonable based on the quotes I've had.

I had the quote back from my 2nd company today, they have given a few options:

Option 1)
The Supply installation and commissioning of a multi-split air-conditioning system serving 2 x wall-mounted fan-coils.

£2,100.00 ex VAT (Mitsubishi SRK20ZS-S)
£2,620.00 ex VAT (Daikin FTXM20N)

Option 2)
The Supply installation and commissioning of a multi-split air-conditioning system serving 3 x wall-mounted fan-coils. (Study, Lounge and master bedroom.)
This option will require a power supply direct from the distribution board

£3,200.00 ex VAT (Mitsubishi SRK20ZS-S)
£3,950.00 ex VAT (Daikin FTXM20N)
£350.00 ex VAT (Applies to both variants)

Option 3)
The Supply installation and commissioning of wall-mounted split system in the master bedroom. (power for this system will be taken from a local plug)

£1,050.00 ex VAT (Mitsubishi SRK20ZS-S)
£1,190.00 ex VAT (Daikin FTXM20N)

The Mitsubishi units don't have wifi built in, they said it's £75 for the module per indoor unit, so whilst it's cheaper it isn't that much cheaper once the wifi thing is built in.

These are both 2kw indoor units, so only 7000 BTU each. I guess the outdoor unit is 4kwh in both cases. I could go with bigger systems but it looks like 2kwh is good enough to cool down a 20sqm room quite easily, and my lounge being the bigger room there is about 3.5 x 5M so not quite 20sqm.

For option 2 I assume it needs more power as the outdoor unit must be rated for up to 6kwh, which must need a higher draw than I can safely take from the plug that is already present.

My original quote from 1st company is here: https://forums.overclockers.co.uk/posts/33678297

In the original quote they were pushing the Toshiba ones, but also said they can do the Mitsubishi Electric ones. Those Mitsubishi Electric units do indeed look a bit fancier!

Being honest the Heavy Industry ones and the Daikin ones both look a bit meh, I do like shiny things!

I don't know why the first quote wants to put the larger unit in the lounge, I think that is probably overspecced for the size of the room.

 

[norm]

Have you looked at sourcing your own equipment and getting an installer after?

www.saturnsales.co.uk are very helpful

 

[HungryHippos]

Have you looked at sourcing your own equipment and getting an installer after?

www.saturnsales.co.uk are very helpful

Not really, but I guess the installers may be getting some profit on the purchase of the kit + if they get it they know the distribution chain then?

I would be happy to buy the kit and get the installers to install it after, but I reckon some may not want to touch if it they aren't also supplying it?

 

[fobose]

It looks like you've got a lot to think about! Will it be a real pain to run power from the main board? It would have been a right pain for me as my mainboard is in my hall way by my front door and the external AC unit is at the back of the property! My 5.5kw outside unit needed to be on a 20a circuit IIRC. Mine are rated at 32A so I probably could have gone for the next unit up (7.5kw).

My 2.5kw units cool my rooms very easily (two are less than 10sqm ). My master bedroom is a touch over 17sqm with a high ceiling by the bay window and an en-suite about half that (it's a large en-suite). It cools them both no problem at all on 3/5 fan speed (basically silent to me). The unit does not run constantly either, once at temperature it runs for about 1-2 mins before cutting out each time. It got warm in the house yesterday morning so I stuck the master bedroom on and left the door to the hall way open. It got the temp in the room to 21.5c and the stairs and landing below were noticeable cooler than my office (26.5c - to which I stuck the AC on in there too).

Re the wifi modules. So far I have not been using the app at all. The remote control does not talk with the wifi module so if you turn the unit on over the wifi, the remote doesn't think the unit is on. It's not a problem as a press of the power button turns the remote on and then you can adjust the temperature with the remote. Maybe I am just old school and like the remote I am yet to control it with Alexa although I think I will set that up today as that will be cool

 

[HungryHippos]

It looks like you've got a lot to think about! Will it be a real pain to run power from the main board? It would have been a right pain for me as my mainboard is in my hall way by my front door and the external AC unit is at the back of the property! My 5.5kw outside unit needed to be on a 20a circuit IIRC. Mine are rated at 32A so I probably could have gone for the next unit up (7.5kw).

My 2.5kw units cool my rooms very easily (two are less than 10sqm ). My master bedroom is a touch over 17sqm with a high ceiling by the bay window and an en-suite about half that (it's a large en-suite). It cools them both no problem at all on 3/5 fan speed (basically silent to me). The unit does not run constantly either, once at temperature it runs for about 1-2 mins before cutting out each time. It got warm in the house yesterday morning so I stuck the master bedroom on and left the door to the hall way open. It got the temp in the room to 21.5c and the stairs and landing below were noticeable cooler than my office (26.5c - to which I stuck the AC on in there too).

Re the wifi modules. So far I have not been using the app at all. The remote control does not talk with the wifi module so if you turn the unit on over the wifi, the remote doesn't think the unit is on. It's not a problem as a press of the power button turns the remote on and then you can adjust the temperature with the remote. Maybe I am just old school and like the remote I am yet to control it with Alexa although I think I will set that up today as that will be cool

Yeah my situation with the power is similar, the fuse box is near the front door, and the unit location would be around the rear of the property.

Not sure what the biggest outside unit is I can run off the existing power that is already there though, maybe 16A? the bigger ones seem to need more.

 

[fobose]

What are your sockets rated at on your fuse box? All of mine are on 32A MCB's. 7500W / 240V = 31.25A so maybe I would not have been able to go up to the next size unit (7.5kw) after all. Would not leave much room to use anything else in the house.

The AC guy did ask me what other equipment I ran off my sockets during the quote stage. I mentioned the usual; kettle, iron, coffee machine, kitchen aid etc etc.

 

[HungryHippos]

What are your sockets rated at on your fuse box? All of mine are on 32A MCB's. 7500W / 240V = 31.25A so maybe I would not have been able to go up to the next size unit (7.5kw) after all. Would not leave much room to use anything else in the house.

The AC guy did ask me what other equipment I ran off my sockets during the quote stage. I mentioned the usual; kettle, iron, coffee machine, kitchen aid etc etc.

Not sure, does this help?

Spoiler

 

[fobose]

Same as mine (B32 = 32A) on both your upstairs and downstairs socket. I think with your 3 rooms from your first Mitsu quote (3500w, 2500w, 1800w / 240v = 32.5A) you have too much draw which is why he probably suggested to put in its own run. Both the smaller units (2500w +1800w / 240v = 17.91A) should have been fine though I would have thought but maybe he got to see what else you have plugged in to your sockets etc.

 

[HungryHippos]

Same as mine (B32 = 32A) on both your upstairs and downstairs socket. I think with your 3 rooms from your first Mitsu quote (3500w, 2500w, 1800w / 240v = 32.5A) you have too much draw which is why he probably suggested to put in its own run. Both the smaller units (2500w +1800w / 240v = 17.91A) should have been fine though I would have thought but maybe he got to see what else you have plugged in to your sockets etc.

Ah think I got it, so I could realistically have 3 x 2kwh units inside, with an outdoor unit at say 5 or 6kwh (20.8A or 25A respectively) instead, which would give a bit of leeway for other devices running off the sockets to operate without exceeding the 32A limit?

Wouldn't give much headroom at 6kwh but that would only be used if all 3 internal units were running flat out at the same time.