Parts of a Swamp Cooler – Pads, Pump, Float Valve, Blower

All 15 parts on the diagram

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Water side 8

Cooling pads Water soaks them, and air passing through is cooled.
Pump It lifts water from the pan to the distributor.
Water pan (reservoir) It holds the water that the pump sends to the pads.
Float valve It lets in fresh water when the level in the pan drops.
Water supply line It brings fresh water to the float valve.
Water distributor It shares the pump's water among the troughs.
Trough Water fills it and drips evenly onto the pad below.
Bleed-off line It drains a little water all the time to slow scale.

Air side 7

Motor It turns the blower wheel through the belt.
Belt It carries the motor's turning to the blower wheel.
Blower wheel A drum of blades that pulls air through the pads.
Cabinet The box that holds the pads, the pan and the blower.
Duct Cooled air leaves the cooler through it.
Pulleys A small one on the motor, a large one on the blower.
Pad frame It holds a pad in the wall; air enters through its louvers.

How this list was compiled: Every name checked on 2026-09-30, a name kept only where two independent sources use it. Wikipedia, Evaporative cooler (https://en.wikipedia.org/wiki/Evaporative_cooler); US Department of Energy, Energy Saver, Evaporative Coolers (https://www.energy.gov/energysaver/evaporative-coolers), read in its Internet Archive copy; one cooler maker's owner's manuals for side, down and up discharge coolers (https://archive.org/details/manualsbase-id-589934, https://archive.org/details/manualzilla-id-6932903; one company, one source); a second maker's portable cooler manual (https://archive.org/details/manualzilla-id-5690119); a third maker's window cooler manual (https://archive.org/details/manualzilla-id-6165224). This page is not connected with or endorsed by the Department of Energy. Hints and detail lines are in our own words. Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; a schematic of no maker's product, nothing traced. Licence: own work

How it works

The parts of a swamp cooler do two jobs: one set keeps the pads wet, and the other moves air through them. The drawing takes the front panel off an evaporative cooler, so the water side and the air side both show.

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The water side

The float valve lets fresh water in from the water supply line and shuts when the pan is full. The pump stands in the pan and sends water up a hose to the water distributor. Its tubes fill a trough over each pad, and the water runs down through the pad and back to the pan. A thin bleed-off line drains a little water all the time, which slows scale.

The air side

The motor turns a small pulley, and the belt carries that to the large pulley on the blower wheel. The wheel pulls outdoor air in through the wet pads, where some of the water evaporates and cools it, and pushes it out through the duct.

Typed answers take reservoir for the water pan and squirrel cage for the blower wheel.

Questions and answers

What are the main parts of a swamp cooler?

A cabinet with cooling pads in its sides, a water pan under them, a pump and distributor that keep the pads wet, a float valve that keeps the pan full, and a blower wheel turned by a motor and belt.

How does a swamp cooler work?

The blower pulls outdoor air through pads soaked with water. Some of the water evaporates, which takes heat from the air, and the cooler air is blown indoors. It suits places where the air is dry.

What does the float valve do in a swamp cooler?

It keeps the water in the pan at one level. The float rides on the water: as the level drops the valve opens and lets in fresh water, and as the float rises again the valve closes.

Is a swamp cooler the same as an evaporative cooler?

Yes. Swamp cooler is an everyday name for an evaporative cooler, a machine that cools air by evaporating water into it. Desert cooler is another name for the same machine.