Dehumidifier & Humidifier Wattage: Are They Expensive to Run?
Detailed analysis of compressor-driven moisture control power draws.
Dehumidifier & Humidifier Wattage
Controlling indoor humidity is essential for comfort, health, and protecting your home from mold or dry-rot. However, the appliances that regulate moisture—dehumidifiers and humidifiers—operate very differently and have vastly different electrical wattage footprints.
Dehumidifiers: High Wattage Compressors
A dehumidifier operates using the exact same technology as a refrigerator or an air conditioner. It uses a compressor to pump refrigerant, cooling a set of coils. As room air passes over the cold coils, moisture condenses into water and drips into a bucket. The air is then reheated and exhausted back into the room.
Because they run an active refrigeration compressor and a fan, dehumidifiers are high-wattage appliances.
| Dehumidifier Capacity | Typical Running Wattage | Monthly Cost (Running 12 hrs/day @ $0.15/kWh) |
|---|---|---|
| Small (20-22 Pint) | 250W - 350W | $13 - $19 |
| Medium (30-35 Pint) | 400W - 550W | $21 - $30 |
| Large (50 Pint) | 600W - 750W | $32 - $40 |
| Whole-House / Crawlspace | 800W - 1,200W | $43 - $65 |
Humidifiers: Low to High Wattage
Humidifiers add moisture to the air, and their wattage depends entirely on the technology they use to accomplish this.
1. Cool Mist (Evaporative & Ultrasonic)
Cool mist humidifiers are incredibly energy efficient. Evaporative models use a small fan to blow air over a wet wick, while ultrasonic models use a tiny vibrating plate to atomize water into a fine mist. Neither uses heat.
- Typical Wattage: 15W to 40W
- Energy Impact: Virtually unnoticeable on your electric bill.
2. Warm Mist (Steam Vaporizers)
Warm mist humidifiers boil water to create steam. Boiling water requires massive amounts of energy. These units contain electric resistive heating elements.
- Typical Wattage: 250W to 400W
- Energy Impact: Moderate to high, depending on run time.
Sizing for Efficiency
To optimize energy use, sizing is key.
Dehumidifiers: It is often more energy-efficient to buy a slightly larger capacity dehumidifier than you need. A 50-pint unit might run for 4 hours to clear a basement, drawing 700W (2.8 kWh total), whereas a 20-pint unit might struggle, running continuously for 24 hours drawing 300W (7.2 kWh total), ultimately costing you more money to do the same job.
Conclusion
When battling summer humidity, be prepared for dehumidifiers to add a noticeable bump to your electric bill, similar to running a small window AC. In the winter, when adding humidity, opt for ultrasonic or cool mist humidifiers to keep your wattage draw near zero.