Match your dehumidifier to the square footage and moisture level of your space

Aprilaire dehumidifiers are sized by the amount of moisture they remove per day, measured in pints. A unit that removes 70 pints per day works in a smaller or drier space; a 130-pint model handles larger areas or very wet conditions. The right size depends on three things: the square footage of the room or rooms you want to dehumidify, how wet the air currently is, and whether you are running the unit year-round or seasonally.

Undersizing leaves moisture in the air and mold risk high. Oversizing wastes energy and cycles on and off too often, which shortens the compressor's life. Aprilaire publishes sizing charts for each model, and your HVAC contractor can also run the numbers based on your home's layout and current humidity readings.

Key Takeaways

  • Aprilaire dehumidifiers are rated by pints per day: 70, 95, 130, and 150 pints are common sizes for residential use.
  • A 70-pint model handles up to 1,500 square feet in moderately damp conditions; a 130-pint handles 3,000 square feet or very wet basements.
  • Measure your current indoor humidity with a meter before buying; if it reads above 60 percent, you need a larger unit than the square footage alone suggests.
  • Aprilaire whole-home dehumidifiers connect to your furnace and ductwork, so installation by an HVAC technician is required.

How Aprilaire sizes its dehumidifier line

Aprilaire makes dehumidifiers in four main residential sizes: 70, 95, 130, and 150 pints per day. The pint rating tells you how much water the unit pulls from the air in 24 hours under standard test conditions (86 degrees Fahrenheit, 60 percent relative humidity). Real-world performance varies with temperature, humidity, and airflow, but the pint rating is the standard way to compare units across brands.

The company also makes commercial models rated at 180 pints and higher, but those are for warehouses, data centers, and industrial spaces. For a house or apartment, you are choosing from the four residential sizes.

Match pint capacity to square footage and current humidity

Aprilaire's sizing guide starts with square footage. A 70-pint model is rated for up to 1,500 square feet in moderately damp conditions (indoor humidity between 50 and 60 percent). A 95-pint handles 2,000 square feet. A 130-pint covers 3,000 square feet. A 150-pint is for 4,000 square feet or larger homes, or for any size home with very wet conditions like a basement that floods seasonally or a crawlspace with standing water.

But square footage is only the starting point. If your current indoor humidity is already above 60 percent—measure it with a digital humidity meter, which costs $15 to $30—you need the next size up. A basement that reads 75 percent humidity needs a 130-pint unit even if it is only 1,200 square feet, because the unit has to work harder to pull moisture out of very wet air.

If you are dehumidifying a single room or basement rather than the whole house, measure just that space. A finished basement of 800 square feet with humidity above 65 percent calls for a 95-pint unit, not a 70-pint, because the concentrated moisture load is higher than in a larger, drier space.

Understand how Aprilaire whole-home models connect to your HVAC system

Aprilaire dehumidifiers designed for homes are whole-home units that connect to your furnace and ductwork. They do not sit in a corner like a portable dehumidifier. Instead, a technician installs them in your basement or mechanical room, ties them into the return air duct, and runs a drain line to a floor drain or sump pump.

Because they use your furnace's blower to move air through the dehumidifier, they work continuously and evenly throughout the house. The trade-off is that installation requires an HVAC contractor—you cannot unbox it and plug it in. Installation typically costs $500 to $1,500 depending on your ductwork layout and whether a drain line already exists.

If you do not have a furnace or ductwork (common in apartments, some newer homes with heat pumps, or homes with radiant heating), an Aprilaire whole-home unit will not work. In that case, a portable dehumidifier from another brand is your only option.

Account for seasonal use and climate

If you live in a dry climate and only need dehumidification in summer, a smaller unit may be enough. If you live in a humid region or have a basement that stays damp year-round, size up. Aprilaire units run continuously when humidity exceeds your set point (usually 50 to 55 percent), so a unit that is slightly oversized will straightforward cycle less often and use less energy than one that is constantly running at full capacity.

A unit that is too small will run constantly and still not bring humidity down to your target. Over time, that constant runtime wears out the compressor faster than normal cycling would.

Check the specifications sheet for your model

Aprilaire publishes a sizing chart with each dehumidifier model. The chart shows pint capacity, square footage range, and the humidity level at which each size is recommended. You can find these on Aprilaire's website or ask your HVAC contractor for a printout.

The model number also matters. The Aprilaire 1830 is a 70-pint unit; the 1850 is 95 pints; the 1860 is 130 pints; and the 1870 is 150 pints. (Model numbers change over time, so always check the spec sheet for the pint rating rather than relying on the number alone.)

If you already have an Aprilaire furnace or air handler, your contractor may recommend a model that integrates directly with it, which can simplify installation and controls. If you are adding a dehumidifier to an existing non-Aprilaire system, any Aprilaire model will work as long as you have ductwork and a drain line available.

Frequently Asked Questions

Can I use an Aprilaire dehumidifier in a basement without a furnace?

No. Aprilaire whole-home dehumidifiers require a furnace and ductwork to operate. They use the furnace blower to pull air through the unit. If your home has no furnace—such as homes with heat pumps, radiant heating, or apartments—you will need a portable dehumidifier from another brand instead.

What humidity level should I set my Aprilaire dehumidifier to?

Most homes are comfortable between 30 and 50 percent relative humidity. For basements and crawlspaces, 50 to 55 percent is typical to prevent mold while avoiding over-drying. Your Aprilaire unit has a humidistat that lets you set the target; the unit runs whenever humidity rises above that point and stops when it reaches it.

Is a 70-pint Aprilaire enough for a 1,500-square-foot basement?

It depends on how wet the basement is. If humidity is currently 50 to 60 percent, a 70-pint unit is adequate. If humidity is above 65 percent, or if the basement has had water intrusion, step up to a 95-pint model. Measure your current humidity before deciding.

How much does an Aprilaire dehumidifier cost to install?

The unit itself ranges from $800 to $2,000 depending on size and model. Installation by an HVAC contractor typically costs $500 to $1,500, depending on whether ductwork modifications or a new drain line are needed. Ask for a quote before committing.

Can I install an Aprilaire dehumidifier myself?

Installation requires connecting the unit to your furnace's return air duct, setting up a drain line, and configuring the humidistat to work with your heating system. This is a job for a licensed HVAC technician. Improper installation can damage your furnace or create air leaks that waste energy.