Cassettes in server rooms

[back2space]

Had a recent issue with a cassette in server room keep icing up... Already was running on high fan speed so solution we have found is to put it on high ceiling mode has increased the air flow it further and now no longer ices up. Maybe this is old news but thought I would share.

[install monkey]

whats the humidity level in the room- can affect performance.
did a fujitsu cassette in a server room once,hard wired controller- kept freezin up every 3 mth, they kept stickin it on 16 - so it ran its nuts off and the condensate in the driptray froze- and blew some of the dell servers.
6mth later had to construct a 1200mm sq drip tray ,insulate it,run a 15mm drain via a tank connector and fit it using screwed rod and unistrut- thus not restricting airflow off the cabinet,but also to catch any future drips- it was non inverter too which didnt help

[back2space]

whats the humidity level in the room- can affect performance.
did a fujitsu cassette in a server room once,hard wired controller- kept freezin up every 3 mth, they kept stickin it on 16 - so it ran its nuts off and the condensate in the driptray froze- and blew some of the dell servers.
6mth later had to construct a 1200mm sq drip tray ,insulate it,run a 15mm drain via a tank connector and fit it using screwed rod and unistrut- thus not restricting airflow off the cabinet,but also to catch any future drips- it was non inverter too which didnt help

The humidity is quite low but set point a reasonable 20C.

[The Viking]

back2space,

The Daikins (and most other units designed for comfort cooling) requires a humidity of at least 35%. Anything lower than that and you will start to get problems.
Normally the first signs of low humidity on the Daikin units are that the unit doesn't keep the temperature, when the humidity drop and the coil start to freeze up the unit should go in to defrost mode. The off cycle in defrost mode might last in excess of 15min and it can take as little as 10min to start the next off period, causing the system to only cool for 20-25 minutes per hour...
Assuming the unit got a wired remote it would be worth going in to "Mode 41" to check what the sensors thinks the system is doing, you might find that there is a problem there.

:cool:

[back2space]

Sorry I should have said they Mitsubishi cassettes. No issues since putting in high ceiling mode. Even tried set point down to 19c and it worked fine :)

[chemi-cool]

I think the choice of chassettes is wrong, servrs rooms needs a lot of air and not under 20C or you might get condensation on electronic parts,

Best solusion i have used is a small AHU that pushes the air through the cabins of the servers,

Throwing cold air from the ceiling will not reach inside and cool the hot parts, you dont have to feel cold when you enter a server room, it the elements insde the servrs that should be cool.