Split Air con

Firestar_3x · 3 Jul 2020 at 15:09

First internal unit went up in the Office today, had to remove an odd wall light an some chased in cables and a switch (left of unit) so need to smooth the filler then paint.

Going to place the next indoor unit then look at cutting through the ceiling and start running pipes / electric.

norm · 3 Jul 2020 at 17:07

Are you planning to use a condensate pump then @Firestar_3x ? I'd be interested to know how much noise it makes if any, as I did consider using one.

Got the rotary isolator and wiring completed outside, a good chance to use my new cable crimper tool.

Firestar_3x · 3 Jul 2020 at 17:45

@norm, Yep need to use some pumps, upstairs rooms are in the eves, these two rooms have minimal access to flat outside walls, so to avoid trunking all over the place i've gone into the loft instead.

Pumps are Aspen mini limes, they sit in the corner trunking part and put out minimal noise when running (21dba) and only run when the small reservoir fills up.

https://www.aspenpumps.com/mini-pumps/silent-mini-lime-new

Still not decided on the location of the outdoor unit, so need to get thinking about that!

fobose · 3 Jul 2020 at 20:57

There are some very neat setups going on atm. One of my rooms was also up in the eves @Firestar_3x but I was quite lucky and found a waste pipe the condense could go in to. Cool little condense pump though, very clever!

Firestar_3x · 5 Jul 2020 at 17:51

I could have gone into an airing cupboard and done similar, but decided its easier in the future to fix a ceiling than a 63mm hole in the wall

Second internal unit is up and outdoor unit placed, it is well out of the way round the side of the house and exactly 1m from the boundary, set the unit at a height so i can still easily get things like wheelbarrows under / around (for when i do the garden) core drills have turned up so sticking a 107mm hole through the side of the house is my next job!

When we AC the rest of the house i will probably end up installing the next unit directly above this one.

HungryHippos · 5 Jul 2020 at 17:58

Looks like a good location there nice and out of the way!

norm · 5 Jul 2020 at 18:28

Nice job @Firestar_3x how do plan to get power to the compressor?

Your wall bracket looks the same as mine did you order yours from Saturn Sales too? You may want to reconsider the mounting, by drilling into the brick to fix the wall plugs instead of the mortar, as the mortar may weaken and pull out over time.

I went to vacuum test my setup today after finishing it all, and lo and behold the 1/4" connector on the hose doesn't fit the service port on the compressor which uses a 5/16" fitting, so have ordered an adapter for tomorrow.

Firestar_3x · 5 Jul 2020 at 19:36

Yea Saturn Sales, i have a spare 32amp mcb that used to feed a shower so plan on using that, the cable already goes into the loft so will join with a 32amp junction box and run cable to the exterior unit using the AC pipe trunking.

Will be getting an electrician in to do the above, as it is the most likely thing out of all of this to burn the house down.....

Bracket is fixed using those expanding metal anchor bolts, should be solid, but i do plan on putting two extra holes directly into the brick through the two lower arms, bracket is tested to 420kg and the unit is only 40kg so should be more than strong enough!

norm · 6 Jul 2020 at 20:13

Running the vacuum pump earlier. Had it on for 15 mins and held -30inhg for the following 15 mins, so surely a good sign.

Going to run in again for 30 minutes this time and leave it overnight. Hopefully there are no leaky connections on the manifold or hoses.

All proving well will release 5 seconds worth of refrigerant tomorrow and do a bubble test on the flare nuts.

RJC · 6 Jul 2020 at 20:25

@norm did you get a torr gauge?

That will be far better for doing a rise test. Vaccing over night is bit extreme assuming your trusting the valves in the system not to let by :eek:

norm · 6 Jul 2020 at 20:33

RJC said:
@norm did you get a torr gauge?

That will be far better for doing a rise test. Vaccing over night is bit extreme assuming your trusting the valves in the system not to let by

I would have liked digital vacuum meter but it's a bit hard to justify the expense for a one off installation. Guides online and YouTube videos seem to have success just using the manifold guage method to monitor no changes.

I wasn't going to run the vacuum pump overnight, only 30 mins, then leave the guage attached to see if it's lost any vacuum the following morning, how reliable this will be I'm not sure as you then the valves could be leaky on the manifold.

I think for complete reassurance it has to be a nitrogen test at 200psi, but that's £134 for a regulator and £40-50 for a bottle of nitrogen? Again hard to justify.

RJC · 6 Jul 2020 at 20:42

@norm shame your not more local. I have a bottle of OFN in the garage, torr gauge (not calibrated) and regulator.

Best bet is to vacuum much as you can tonight - you can leave the gauges on but make sure all the fittings are tight - assuming there’s no moisture in the system you should not see a rise. Do a quick vacuum tomorrow and open the valve and do as you mentioned.

mattyy · 7 Jul 2020 at 13:30

norm said:
I would have liked digital vacuum meter but it's a bit hard to justify the expense for a one off installation. Guides online and YouTube videos seem to have success just using the manifold guage method to monitor no changes.

I wasn't going to run the vacuum pump overnight, only 30 mins, then leave the guage attached to see if it's lost any vacuum the following morning, how reliable this will be I'm not sure as you then the valves could be leaky on the manifold.

I think for complete reassurance it has to be a nitrogen test at 200psi, but that's £134 for a regulator and £40-50 for a bottle of nitrogen? Again hard to justify.

Its looking like a really decent install, despite breaking the F-Gas regs on the way

.

Ref the vac stage - the procedure is to actually test with nitrogen for leaks. The main reason a system is 'vac'd' is to dehydrate the system from moisture by boiling it off in a vacuum. Moisture is not something you want in a system and will cause a whole host of issues. The chances of having moisture in a newly installed system is minimal if the pipework has been stored correctly to reduce its exposure to it. Equipment comes prechareged with either refrigerant or a holding charge of nitrogen to prevent this. (nitrogen is also something you dont want in your system as most compressors do not like it - again something else you ideally want to 'boil' away in the dehydration stage)
Using a vacuum pump to leak test will work as you would obviously not generate a vacuum - however, at the lower limit of the gauge that would only indicate a rather large leak, a rise test would help with a smaller leak. Unfortunetly, without a digital vacuum gauge there isnt really any way of knowing at this stage if the system is completly leak tight and the potential to actually introduce moisture into the system by using a vac pump will always be there.

I would do as RJC suggested but I would vac for a few hours. Don't get too concerned with letting just a little refrigerant out to carry out a bubble check as I doubt you'll get enough pressure to detect anything that vacuum rise test wouldnt of already indicated. Instead I would release it all and then run the system on 'heat' to generate the most pressure in the pipework and do a bubble test. If you then detect a leak then you can pump the system down to tighten the flare up safely - and kick yourself for not pressure testing

. The only two things that will prevent any moisture or refrigrent loss within the system is presssure testing and a digital vacuum gauge at this stage.

norm · 7 Jul 2020 at 15:06

Refrigerant has been released, spent some time spraying leak detector over the flare nuts and no bubbles found.

I think the fact I practiced making flares a lot and used a torque wrench to tighten the connections helped ensure a good seal.

Here's a photo of the pipes in the loft, used a bit of leftover rail and stands from my loft zone floor to support the pipes.

Duke · 8 Jul 2020 at 11:34

What is the approx size of the outside and inside wall units please? As much as I'd like split AC, I don't think I have room where I'd prefer it to be. Going to also look at alternatives (think there is a air pump or something else which may help a bit but obviously not as good as AC). I gather you can get water cooled AC as well but its more expensive.

Firestar_3x · 8 Jul 2020 at 11:55

Duke said:
What is the approx size of the outside and inside wall units please? As much as I'd like split AC, I don't think I have room where I'd prefer it to be. Going to also look at alternatives (think there is a air pump or something else which may help a bit but obviously not as good as AC). I gather you can get water cooled AC as well but its more expensive.

Typical indoor and outdoor unit sizes can be found here:

https://www.saturnsales.co.uk/images/products/editor/Mitsubishi SCM45ZS-W.pdf

1pudding1 · 14 Jul 2020 at 08:22

Hi all,

Finally had my parts delivered this week for a Daikin triple indoor unit multi split install. It included a 2x25m rolls of copper tubing, 1/4" and 3/8". For those who've just installed recently, whats the best/easiest way to route and pull the copper around?

I'll be going into and through a stud wall and through ceiling joists as it's being installed in an extension which is not plasterboarded yet, so a few corners needed. I'm trying to think of the best way to avoid bending every inch of the copper as I pass it through the timber studs/joists and around corners. Would it be to cut each run approximately to length, then starting from the indoor units, trying and feed the full, say 10m, length through each hole keeping it as straight as possible, before bending it and then passing it through the next hole? Or is the copper malleable and soft enough that bending the whole 10m run as it passes each corner not going to be a problem? Got a pipe bending spring for the 3/8" tube to help too.

Thanks for any tips.

fobose · 14 Jul 2020 at 08:54

I would get a HVAC installer to do it for you @1pudding1. That would be the easiest option

Are you not concerned about not having any warranty on your nice Daikin units?

1pudding1 · 14 Jul 2020 at 09:20

Not really. The savings made with self-intsall will easily pay for a replacement unit if one dies.

RJC · 14 Jul 2020 at 10:38

@1pudding1 the copper is soft enough to maneuver around the bends, you can use your hands and gently curve the copper (don't go to mad as you will crease the copper) I would start outside and push the copper through to the indoor units - terminate these either by flares or swaging then brazing.

Connect the condensing unit last.