UPS room A/C

[mechman]

how suitable is a split A/C for an UPS room (±15 kW)?
what is the recomended system?

[Magoo]

Standard splits are OK as they usually have high SHR evaps. But you will need fresh air make up [ fan forced ] to keep humidity % up and consider humidity controller as well.

[Tesla]

Also consider extraction (possibly passive) at the heat source but keep the space on a positive pressure. This will reduce the load on cooling.

[RSTC]

personally do not recommend 'split' or comfort air conditioning for comms or ups rooms. Energy in these applications are almost 100% sensible where splits can have a sensible to latent ratio of as little as 45%. Two problems with this: you spec a 15kW unit but only 6.75kW are available, even if you spec a 33kW unit you take huge volumes of moisture out of the air which can lead to higher risk of static discharge.

Other major no no is cassettes (we love em here), sure they don't take up any space but when (not if) the drain leaks your kit is right in the firing line.

A number of close control specialist companies have very good plant with 'free' cooling

[NoNickName]

I don't think a split system is suitable. And I don't think fresh air is a good idea.
Close control units (possibly with free cooling) are the only suitable equipment for properly control high value assets.
Also the average life time for a split system is calculated on few hundreds hours / year. An UPS system works 24/7/365.

In my playfield, for a 15kVA good quality UPS, the heat load is approx 3 to 4kW.

[Magoo]

NNN, how does +/- 15 kw change to 15Kva.

[NoNickName]

It doesn't. That was a bail for the poster, because UPS'es are denominated in kVA, not in kW.

[chemi-cool]

I have done one large servers room with large splits.

Just measured the currant draw for the room, add 50% for the future and installed all the units.

each cabin with severs had a top pulling fan installed, instead of remotes, a wired unit is controlling the temp. the temp control unit is connected to cellular line for high temp alarm.

it works fine for past 2 years.

[r.bartlett]

UPS rooms do not need to be kept very very cool so it would be possible to set the room high to 25- 28 deg c and in that case a split will function ok.

Daikin have a data room setting which will further enable it to run fine or even better fit a 7 kw indoor on a 6kw outdoor unit to get a better ratio (no warranty but better cooling)