Air Source Heat Pumps

thechippy

Ok, keeping tuned. Am going to have a shower while you conduct your tests...:D

richardc1983

Air in temp 22C at floor level which is where the unit pulls its air from

Air off 35.5C.

Room temp 24C measured at controller,

Just been out and felt the outdoor, blowing air cold like it normally does, plenty of water running out from underneath, felt back of the coil, no ice build up anywhere on the coil, particulary at the bottom.

What you think?

Do you have msn mate? Would be a lot easier.

richardc1983

Have you checked this document:

http://mylg.co.uk/data%20for%20site/Multi%20Splits%20commissioning.pdf

It gives no mention whatsoever of the pre charge?

thechippy

Yeh,

Don't worry, the pre-charge is in the main spec...;)

thechippy

Some of my install pics for you Rich....

thechippy

richardc1983

Looks neat mate!

To be fair on the guy hes done a neat job.

thechippy

richardc1983

THechippy can you give me another call when you get this message ive lost your number, my phone reset itself so cant ring you back.

Found out the unit is charged with 2000g or 2kg of refrigerant.

Had this quoted to me on the air con forum but think its wrong, no way does it need another 2kg adding:

"Looking at the links you posted, your outdoor unit is rated at nominal 7.03kW cooling and 8.44kW heating.

With 3 x 3.5kw indoor units connected to it (36000btu's) the total output from the compressor in heating will be split evenly across the 3 indoor units (2.81kW each)(80.38% of rated duty)

Basically, you have connected 3 indoor units, that combined, are bigger than the outdoor capacity.

From the charge aspect, it would appear that the outdoor comes with a 2kg charge suitable for pipework upto 7.5m.

As your total pipework is 39m then an additional 31.5 m needs to be trim charged at a rate of 20g/m. This gives a total calculated charge of 2 + (31.5 x 0.02) = 2.63kg. Now, the charge instructions says to deduct 450g for a size 24 outdoor unit, making a revised total charge of 2.18kg.

If your 'engineer' has added in excess of this then the system is overcharged, according to the Manufacturer."

thechippy

Hi Rich,

Will call you after 7pm. Am a bit tied up till then.
The above is correct, I think you just misread it, he's saying the TOTAL charge should be 2180g.
To confirm the base charge, it is more than likely written on the data plate on the outdoor unit. The system should have base charge + 180g for your current pipe run.
Spk later....