Heat pump / inverter DIY

Hi
Sorry I don't have any knowledge of these units but it sounds interesting and I wondered where you bought it from and do they have a website?
Thanks.

I have air conditioners/heat pumps, but I got them installed professionally.

If you do not use a vacuum pump, then you will not know if you have a leak (the pump evacuates the system & is left for a while to ensure the vacuum holds) & if the refrigerant disappears then you have to get an air-con engineer anyway - you can't re-gas as a DIY'er.

Absolutely fine - the temperature is 4c and they are pushing out heat in prodigious quantities.

According to the documentation they are running at 80% of their COP which is 3.45 therefore the cost is 2.86p per kw.

Mind you oil has dropped so much that I'm only paying 4.3p per kw for that, but it's still a saving I suppose.

I use 2 9000BTU Mitsubushi Units (SRK20-ZGX) to heat my 3 bed end terrace with loft. I decomissioned my old gsh at the end of last winter after getting a £270 gas bill. So far, house is warmer (22 in loft, 23 living room) and last 4 weeks cost £17 for just heat. I work from home, so the house is kept comfortable waking hours. It's easy to measure as I have an energy use monitor on each unit.
Outside temp tonight is 0, and they're still pumping out toasty heat.

I must add that I'm located in SW England which had a mild climate, and frost is a rarity. These ashp's perform amazingly well for me, I'm just bowled over by how cheap they are to run. It's worth noting that the cost of running these units is less than the cost of a service contract for GSH without using any gas at all.

With better insulation, it even looks feasable to micro-generate enough electricity to heat your own home!
ASHP's ROCK, and if you live in a mild climate, are cheaper than GSHP's; cheaper than the best gas, cheaper than chips even.

Oh... and they're useful in the summer too

DOnt under any circumstances even attempt to install these units yourselve. The same as to handle Gas boilers you have to be corgi registered for Air con you have to have refrigerant handling certificates and qualifications. How do you know how to vac it, how long for? What pressures you should be running to, how much gas to put in the system? Testing and commisioning of the system. Tell these cowboys who are trying to sell them to you where to go and get a proper installer to do it. YOu will end up breaking the equipment because you dont know what your doing and this will cost more to put right in the long run.

On the other hand I have 2 x LG Multisplit system installed consisting of 1 x outdoor unit FM25AH and 2 indoor convertible MV12AH units. The system was installed in June and cools the whole flat perfectly sometimes only needing 1 unit on.

Now its winter currentlly -2 outside and im getting air off temps from the units of 35C which is making my house a lovely 23c throughout. I find that when I go to bed it uses less electric to leave the system on but set to 18C as it doesnt have to work as hard and for as long when I put it back upto 23c the next day.

IN regards to defrosting the unit because it is cycling on and off happily maintaining indoor temps it doesnt defrost much at all however when the units have been switched off and the indoor temps drop to 13c the system will run for about 4hrs to get indoor temps up, in this time the outdoor coil will go white with ice and the unit will defrost mode about twice during this period.

Excellent systems. We had it installed as we cannot control our heating in our flat as the landlord runs it so when its off we had to rely on electric heaters. This way the house is always warm.