The unit is not the expensive part. Installation, the hole in your wall and the electrical work are, and they vary by a factor of four between a cellar and a closet conversion.
| System | Unit only | Installed | Where it fits |
|---|---|---|---|
| Self-contained through-wall | $1,000-2,000 | $1,300-2,800 | An exterior wall, an accessible vent, 300-1,500 bottles |
| Ducted (remote condenser) | $2,500-4,500 | $4,000-7,500 | No exterior wall available; waste heat sent to a garage or attic |
| Split system | $3,000-5,500 | $5,000-9,000 | Larger rooms, quieter operation, condenser outside the house |
Add $200-800 for electrical work if there is no dedicated circuit, and $150-400 for the wall opening and finishing on a through-wall install.
Self-contained units typically draw 300-600W while running, and run somewhere between 40% and 70% of the time depending on ambient and insulation. A realistic monthly figure is 130-260 kWh, or roughly $16-45 a month at US average rates — more in a hot climate with poor insulation, less in a basement.
Two things move that number more than the brand: insulation and where the waste heat goes. A unit venting into a closed garage recycles its own heat and runs near continuously. That single mistake can double the electricity bill and halve the compressor's life.
A modified domestic air conditioner or a "cellar cooler" conversion can be bought for $400-700. It will cool the room. It will also over-dehumidify, ice up at cellar temperatures, and typically fail within two to three years because it was never designed to hold 55°F against a 90°F ambient. If the collection is worth more than the unit, the cheap unit is the expensive choice.
Insulate first, size correctly second, buy the unit third. Insulation is the cheapest capacity you will ever buy: going from R-11 to R-19 in the walls can cut the required capacity by a third, which sometimes drops you into a smaller, cheaper unit. Run the numbers in the BTU calculator before you shop, and see the cooling system guide for how each type handles heat and humidity.
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Cooling units are the one part of a cellar where a wrong purchase costs four figures, so it pays to price the same spec in more than one place. Installation is usually quoted separately, and a through-the-wall unit you fit yourself can save $800-1,500 against a split system.
The largest single stockist of cellar cooling in the US. CellarPro is the range most often compared against WhisperKOOL on capacity per dollar. Filter by cubic footage, not by "bottles", when you cross-check against the calculator.
Sold through dealers rather than direct, so pricing varies more than you would expect. Their SC PRO and Slimline ranges cover about 300 to 2,000 cubic feet, which is where most home cellars sit.
Ask any dealer for the unit's rating at your cellar temperature. A unit rated for 55°F in a 75°F room will not hold 55°F in a 90°F garage, whatever the brochure says.
One page: heat gain by room, the derating maths, and the unit size that actually holds 55°F. No newsletter spam.