Does liquid cooling eliminate the need for air conditioning?

No. Liquid cooling moves heat out of the servers but not out of the building. A liquid-to-air (L2A) cabinet rejects its heat into the deployment room, so the room needs air conditioning sized for roughly 1.1 times the IT load. Liquid-to-liquid systems transfer the requirement to facility water loops and dry coolers instead.

How much air conditioning does a 30 kW liquid-cooled rack need?

About 33 kW of cooling capacity (1.1 × 30 kW), which is roughly 9.4 refrigeration tons. Add redundancy on top: an N+1 design needs one more unit than that math demands.

Formula · 2 min read

Room AC load — the 1.1× rule

A liquid-to-air (L2A) cabinet still needs room air conditioning sized for about 1.1 × the IT load: a 30 kW rack needs ≈ 33 kW ≈ 9.4 refrigeration tons of cooling in the room. Liquid cooling moves heat; it does not destroy it.

Formula

P_AC [kW] ≈ 1.1 × P_IT [kW] → tons = P_AC / 3.517

The L2A cabinet rejects essentially all IT heat — the liquid share through its own air-to-liquid heat exchanger, the rest straight off the servers — into the room. The extra 10% covers pumps and power losses plus commissioning margin. Liquid-to-liquid (L2L) systems move the same requirement to facility water and dry coolers instead.

Worked example

40 kW edge room → 44 kW AC ≈ 12.5 refrigeration tons

A hospital server room hosting a 40 kW liquid-cooled rack needs 44 kW (1.1 ×) of air conditioning — about 12.5 tons. An existing 10-ton unit is not enough; the verdict below does this comparison for your numbers.

Try it

IT load (kW)Existing room AC (tons)

33.0 kW ≈ 9.4 tons needed

⚠️ Fits, but under 15% margin — no N+1 headroom

Common mistakes

"Liquid cooling means no air conditioning." No. Anyone telling you otherwise is selling, not engineering. L2A relocates heat into the room; the room still removes it.
Confusing cooling tons with electrical draw. A "12-ton" AC removes 42 kW of heat but draws far less electricity (typically a third, depending on COP/EER).
Forgetting redundancy. The rule sizes the requirement, not the fleet — N+1 redundancy means one more unit than the math demands.

Room load calculation (full worked guide + site survey) · kW ↔ tons · Hot & tropical climates

Sources

1.1× convention used across this site's tools (room-load calculator, rack builder); 1 refrigeration ton = 3.517 kW (12,000 BTU/h).