|
|
Post by DIYDafty on Jul 8, 2023 20:01:14 GMT
Well, after a lot of fun and games that's my first heat pump/aircon mini split happily installed.  Most interesting part for me was the subject of leaks. The system runs in narrow bore copper pipes and runs at very high pressures of several hundred psi. So how do you know if you've got a leak so small it would take months to empty the system? A bit like a slow puncture on a car. Pressure testing with nitrogen (scared me when I first heard of it but the reality is you can get a bottle for 17quid near me but you do need to pay for a regulator). Then vacuum testing which you need to do anyway to get the contaminates out but with a good setup and micron gauge will show up leaks. In my case, I pressurised the system to 230psi. At that pressure my cheap gauges would leak slightly which was really causing me grief. I'd leave the system for hours and then find a drop of say 1 psi - was it down to temperature etc who knows. So I took a tip off an american hvac dude who told me how to keep the system under pressure without any hoses or gauges but still able to check its pressure when you want to. With that rig, I left it for 3 days connecting the gauges only when taking a reading and not releasing any gas. After 3 days and the same temperaure as the first reading, there was zero pressure loss ! Time to release the nitrogen, pull a vacuum and open up the R32..... |
|
|
|
Post by crowsfoot on Jul 9, 2023 9:35:28 GMT
I've always been interested in the technology on how a different air pressure can totally alter how a liquid behaves and I always think who the hell first thought this lot up?
Keep us informed on how the units behaving and your thoughts on it's performance as you go.
The technology behind air con is the same as an ASHP or GSHP so it could help the forum solve the mystery of why heat pumps are so unpopular in the UK.
|
|
|
|
Post by dickpuller on Jul 10, 2023 16:51:25 GMT
I've always been interested in the technology on how a different air pressure can totally alter how a liquid behaves and I always think who the hell first thought this lot up? Keep us informed on how the units behaving and your thoughts on it's performance as you go. The technology behind air con is the same as an ASHP or GSHP so it could help the forum solve the mystery of why heat pumps are so unpopular in the UK. My understanding cf; Dafty is heating only a couple of Rooms with his Split System. It’s Air to Air unit. |
|
|
|
Post by DIYDafty on Jul 10, 2023 21:08:19 GMT
I've always been interested in the technology on how a different air pressure can totally alter how a liquid behaves and I always think who the hell first thought this lot up? Keep us informed on how the units behaving and your thoughts on it's performance as you go. The technology behind air con is the same as an ASHP or GSHP so it could help the forum solve the mystery of why heat pumps are so unpopular in the UK. Bloody typical that the last couple of days I went into the living room quite late to flick the TV on, the temperature was perfect so no real use out of the new machine. I've got a multi-split in the garage that I'm also about to install now I feel a little more confident. As you know I went in a different direction to what the government seems to be pushing. I'm installing several smaller units rather than one big one although my second outside unit will support 3 heads (indoor units). These units have a claimed COP of greater than 6 which anyone who has been on the C&G 2079 course (mentioning no names) will know means that in ideal/lab conditions for every 1Kw you put in, you get 6Kw of heat out which is pretty incredible. No doubt real world is different.... I'd be quite interested to know what the COP figures are for the big units the government are pushing. Unless they are well above 6 why would anyone bother with one? The small aircon units like I've got sell in their hundreds of millions around the world in some very harsh conditions - I'm sure they are more reliable than these big UK heat pumps that don't have much of a track record. Happy so far but will report back.... Attachments:
|
|
|
|
Post by crowsfoot on Jul 11, 2023 9:02:55 GMT
Looks just like a mini ASHP dd. Can we take it that you'll be mainly be using the units cooling side during this current heatwave? I'm sure that you'd achieve that amazing COP of 6 if you was using the unit for heating purpose during the heatwave ! Like I said before I can't really pass any comment on these units having never had any experience of fitting or repair of them |
|
|
|
Post by dickpuller on Jul 11, 2023 19:16:56 GMT
COP of 6??!, never laughed so much since the Wife died😂😂😂😂😂
Dafty, with your poorly insulated old gaff, you’ll be luck to get a COP of 2!!!
|
|
|
|
Post by crowsfoot on Jul 11, 2023 19:16:59 GMT
I've always been interested in the technology on how a different air pressure can totally alter how a liquid behaves and I always think who the hell first thought this lot up? Keep us informed on how the units behaving and your thoughts on it's performance as you go. The technology behind air con is the same as an ASHP or GSHP so it could help the forum solve the mystery of why heat pumps are so unpopular in the UK. My understanding cf; Dafty is heating only a couple of Rooms with his Split System. It’s Air to Air unit. Yeah, there's no radiators or hot water involved - it's just the air only that's being processed by these units. It's still the same evaporation, condensation, compression, technology of ASHP, GSHP that's behind it though. |
|
|
|
Post by dickpuller on Jul 11, 2023 19:34:13 GMT
My understanding cf; Dafty is heating only a couple of Rooms with his Split System. It’s Air to Air unit. Yeah, there's no radiators or hot water involved - it's just the air only that's being processed by these units. It's still the same evaporation, condensation, compression, technology of ASHP, GSHP that's behind it though. Oh absolutely cf, for an air to water ASHP, they use a Stainless Steel Plate Heat Exchanger, one side is the Fridge Gas & the other the CH Water. A Split Unit with the Condenser indoors & the Fridge Line-Set(3/8th&1/4) is connecting the two units. We did Holiday Chalets 12 years ago, where the only Heating/AC was two mini-split units. I was on a New Build today, where it was a Hybrid system being fitted, small Gas Boiler & small ASHP. I was fitting the UV Cylinders & was too busy to get any photos. We get paid Target times, so today fitted two cylinders @ 10hours each. The Target times for the Gas Boiler, ASHP etc is crap & there’s a lot of work in doing them, so I refused to do them. |
|
|
|
Post by DIYDafty on Jul 11, 2023 23:11:49 GMT
COP of 6??!, never laughed so much since the Wife died😂😂😂😂😂 Dafty, with your poorly insulated old gaff, you’ll be luck to get a COP of 2!!! First of all, if you remember from your course, you'll know insulation has nothing to do with COP. The SCOP figure is 6.4 in my zone which is the average COP throughout the heating season. I wouldn't sneer - these units are tried and tested throughout the world unlike our air to water overly complicated jobbies. Each inside unit costs £160 retail. Checkout the noise levels too. Oh and they're pretty good at cooling too  P.S. Nice to see they do a specific spec sheet just for the UK market. Attachments:
|
|
|
|
Post by crowsfoot on Jul 12, 2023 6:52:47 GMT
Some good information there from Dick and dd. I've learned a bit of something from each post.
What happens to the economy dd though when you need to have six of these air to air individual units all running at the same time weighed against just the one (complicated) air to water ASHP unit running but supplying heat to 6 individual rooms.
Be nice to see a few photos of these units Dick but then again I do appreciate that you can't really go about a building site taking photos of things.
Sad to hear that the "swings and roundabouts" bonus mentality is still prevalent on sites I thought that we had got rid of all that nonsense 20 years ago!
|
|
|
|
Post by dickpuller on Jul 12, 2023 18:01:35 GMT
Some good information there from Dick and dd. I've learned a bit of something from each post. What happens to the economy dd though when you need to have six of these air to air individual units all running at the same time weighed against just the one (complicated) air to water ASHP unit running but supplying heat to 6 individual rooms. Be nice to see a few photos of these units Dick but then again I do appreciate that you can't really go about a building site taking photos of things. Sad to hear that the "swings and roundabouts" bonus mentality is still prevalent on sites I thought that we had got rid of all that nonsense 20 years ago! I’m a great advocate of the Air to Air mini-Split, they’re cheap & efficient. But like with all types of ‘air heating’, there’s pros & cons. Certainly, when it goes off, a room will cool down very rapidly. Compared to Under Floor Heating, which in my view is 100% the best form of Home Heating. UFH in a Floor Screed can maintain its temperature for 24 hours, run at lower temperatures - suited to Heat Pumps. Its funny, UFH has been very popular for 40-50 years here & only now is spreading South. As for inconsistencies on Target Times, I believe a lot of Estimators are under estimating the Labour Constant, on some elements of the work. This is due to the lack of experience on their part, with new burgeoning technologies. As for Dafty’s projected unit efficiencies, I’d say he’s more than a little deluded!! I did have a bit of a chuckle at the map, when clearly the highest UK temperatures are in the South East of England & Ireland is not known for it’s tropical climate😂😂😂 |
|
|
|
Post by DIYDafty on Jul 12, 2023 19:29:20 GMT
With Scotland being insignificant, I can forgive Mitsubishi for not including all the map detail to the liking of everyone. These are claimed figures - everyone knows they're produced in lab perfect conditions. But 6.4 is nevertheless a very high claimed figure. I wonder what the claimed figures for the heatpumps that Dick has fitted oh so many of are ?
CF makes a very good point about scaling up. I guess an "average" 3 bed house would ideally have 3 units upstairs and 2 or 3 downstairs? These aircon units do scale up as large as you want but heating efficiency does drop off I admit. So you could get one large pump/compressor for outdoors and then connect 6 heads or two outdoor with 3 each and all the combinations inbetween. I'm not saying for certain these are more efficient but if Dick is really saying the ones he would like to sell to little old Lady's are only COP=2 then it would seem to be the case.
For me though I mainly bought them to use in one or two rooms at a time to avoid putting on the CH. Also gives a bonus of aircon in the summer and some future proof hedging in case gas goes up even more.
Airborne heating is IMO a good thing. Why do I want to wait hours for a slab to heat up and why do I want to be heating the place once I've gone out? Air is instant on and instant off - almost.
|
|
|
|
Post by joinerjohn on Jul 12, 2023 21:05:47 GMT
Give that man a bigger spade 😂😂😂😂😂
|
|
|
|
Post by crowsfoot on Jul 13, 2023 8:07:53 GMT
With Scotland being insignificant, I can forgive Mitsubishi for not including all the map detail to the liking of everyone. These are claimed figures - everyone knows they're produced in lab perfect conditions. But 6.4 is nevertheless a very high claimed figure. I wonder what the claimed figures for the heatpumps that Dick has fitted oh so many of are ? CF makes a very good point about scaling up. I guess an "average" 3 bed house would ideally have 3 units upstairs and 2 or 3 downstairs? These aircon units do scale up as large as you want but heating efficiency does drop off I admit. So you could get one large pump/compressor for outdoors and then connect 6 heads or two outdoor with 3 each and all the combinations inbetween. I'm not saying for certain these are more efficient but if Dick is really saying the ones he would like to sell to little old Lady's are only COP=2 then it would seem to be the case. For me though I mainly bought them to use in one or two rooms at a time to avoid putting on the CH. Also gives a bonus of aircon in the summer and some future proof hedging in case gas goes up even more. Airborne heating is IMO a good thing. Why do I want to wait hours for a slab to heat up and why do I want to be heating the place once I've gone out? Air is instant on and instant off - almost. This was exactly what I was finding (even before the economic crisis hit). A large percentage of the public are simply not interested in supposedly money/climate saving devices that the government are making so called requirements of us to fit. A lot of the public now just want is something to switch on for a warm when they feel cold then turn back off again when they've had a warm? They could be right because whoever can now afford the so called comfort levels of heat in a economic crisis? |
|
|
|
Post by dickpuller on Jul 14, 2023 5:31:23 GMT
We’ll need gas heating for some time to come, simple facts are; houses in the UK are poorly insulated, most only have an 80-100amp Leccy supply, so a Heat Pump is farting at thunder!!
|
|
