Tosh split running fine, but at 2 bar?

[ianybeany]

Hi there

Im new to the forum(find it great though) and i was wondering has anybody an explination of what ive seen today.
I was called out to a job after another guy had performed routine maintenance on it a while back. Basically the unit is in a comms room, with two other units and was making an awful racket from the comp. He put a gauge on it before checking the temperature:confused: , and found it running at 2 bar. He immediatly gave to me saying it was short of gas and needed a pressure test. Fair enough, went in and checked the temp before anything and it was perfect 19C on and 8C off and even throughout the coil. The suction at the outdoor was cold and the condensing temperature from outdoor was 40C air off. Both fans were running at full speed, and indoor fan at high.

Everything temperature wise is good, but can anyone explain the 2bar, bearing in mind the racket from the comp usually means its on the way out
Toshiba Rav 464 a8-pe cool only

[cool#9]

Hello welcome on this forum
I think in this computer room the latent heat is too low. The indoor coil may reach freeze up protection before the sep point of temperature.
I don't know if there is freeze up level on Toshiba air conditionner. I know that Daikin has 3 freeze up level before going down to default...( on inverter it reduces compressor speed ).
You may have liquid back to te compressor if the function doesn't exit on your unit.
A good solution is also to oversize the indoor unit to create a better superheat...
Regards
cool#9

[headgasket]

I think your air off is to hi. if you only have 19 air on, i would expect to see 2-3 air off, short of gas

[allyjg30]

Hi, I have worked loads on tosh a/c. You might find your temps ok but after a while it will freeze up, You will have a choke at the filter inside the condensor.Best move is to cut out the filter and replace it with a flared drier ( fit the drier external to the unit) This way if it happens again you can easily pump it down to change it. allyjg30.

[ianybeany]

Yea thats sounds about right!! Unit had had issues with icing up, but it was a tad under sized too.

No icing up senser and is fixed speed

thanx!

[ianybeany]

Thanks allyjg
i presume the liquid line strainer?

[ianybeany]

Hi cool9 Would putting a humidifier in the room help , so to increase the latent heat??

[allyjg30]

When these units are running on hot outside ambients the unit will also ice up if undersized so you might be right. With the model number you have you will need to change the drier. When you have it out cut it open and you will see all the crap in it. I've done this repair tons of times. when you reclaim the gas, weigh it and that will tell you if you lost gas. If you have an infrared thermometer you can measure the temp diff across your drier to prove your block before tou even start the repair.

[allyjg30]

Yeah, the strainer, you cant miss it. there only is 1.

[cool#9]

Hi cool9 Would putting a humidifier in the room help , so to increase the latent heat??
Hello
In fact in computer rooms you can just try it with a small "boiler" i mean to heat at least 1 liter of water to increase humidity...
Also an inverter drive isn't the best solution in computer rooms...
Regards
cool#9

[frank]

Also an inverter drive isn't the best solution in computer rooms...

Can you explain why that is??

Daikin have designed their RZQ inverter specifically for low latent heat applications, i.e. computer rooms?

[cool#9]

Can you explain why that is??

Daikin have designed their RZQ inverter specifically for low latent heat applications, i.e. computer rooms?
Hi Frank
Yes Daikin have designed the RZQ with a special setup for computer rooms but even in this case i've seen the system reach the freeze up protection( monitoring control by service checker via the serial port ).
In "real" computer rooms ( i mean big ones ) i prefer install a brand like LIEBERT HIROSS with humidifier, electrical heater... it depends on the customer's budget..
Your's sincerely
cool#9

[frank]

Hi Frank
Yes Daikin have designed the RZQ with a special setup for computer rooms but even in this case i've seen the system reach the freeze up protection( monitoring control by service checker via the serial port ).
In "real" computer rooms ( i mean big ones ) i prefer install a brand like LIEBERT HIROSS with humidifier, electrical heater... it depends on the customer's budget..
Your's sincerely
cool#9

I agree with you totally about BIG computer rooms but I don't see why inverter driven splits can't be used for small rooms, say, up to 12kw load?
Capacity control will be better with inverter driven compressor than it will be with on/off compressor?

[cool#9]

Hi Frank
Ok i agree with you up to 12kw if the computer room is open on other space, i mean the computer room is not so "watertight".
Also the choice of the brand and type is important i.e some airconditionner has multi levels to avoid freeze up and then reduce the refrigerant flow... but i think i won't learn you about because you seem relevant enough...Regards.
cool#9