AprilAire E100 Review: 5,500 Sq Ft, Verified Cost

The E100 is the E080’s bigger sibling

If you’ve looked at the AprilAire E080, the E100 will feel familiar — and that’s the point. It shares the same 14-inch-wide, 26-inch-deep, 15-inch-high cabinet and the same 64-pound-class build, but steps the capacity up to 100 pints per day at the AHAM condition of 80°F and 60% relative humidity, versus the E080’s 80. The claimed coverage jumps too, to 5,500 square feet. So the decision between them isn’t about form factor — it’s about whether your space actually needs the extra capacity, because you’re getting it in the same footprint.

That 100-pint figure is the standardized AHAM lab rating, useful for comparing units head to head rather than predicting exactly how much water you’ll pull on a given day. AprilAire doesn’t publish a separate saturation capacity for the E100 — the higher near-100%-humidity figure some brands report — so the AHAM number is the only capacity spec we have, and we won’t invent a best-case figure to sit beside it.

5,500 square feet is a lot of crawl space

Coverage is the E100’s headline, and it’s a genuinely large claim — larger than most homes’ crawl spaces need. That cuts both ways. If your space is big, or badly split into hard-to-reach bays, the E100’s reach and its strong 280 CFM airflow are the argument for it. If your crawl space is average-sized, that 5,500 sq ft is capacity you’ll buy, power, and rarely use. Coverage claims also rest on the manufacturer’s own assumptions about a space, so treat the number as a ceiling rather than a promise, and size against your real volume and climate with our sizing calculator before letting it decide the purchase.

A verified running cost, thanks to ENERGY STAR

AprilAire lists the E100’s current draw as 6.9 amps but, like the rest of the line, no rated wattage — and we won’t multiply amps by volts to invent one, since that gives apparent power rather than the true watts a bill reflects. On its own that would leave the running cost unverifiable. But the E100 is ENERGY STAR certified, and the EPA’s registry publishes a DOE-measured annual energy figure for it: 821 kWh per year. That’s a tested number, not an estimate, so we can give you an honest operating cost after all.

The figure above comes straight from that measured value times your electricity rate — about $131 a year at our default rate, and adjustable to your own state’s rate on the operating cost calculator. It’s a standardized full-year figure, so a crawl space you run only seasonally would cost proportionally less. On a 100-pint unit that can run much of the year, being able to put a real, measured number on the electric bill — rather than an estimate or a shrug — is a genuine advantage, and one the E100’s ENERGY STAR Most Efficient 2025 rating (integrated energy factor 2.35 L/kWh) reinforces.

Airflow, noise, and filtration

Where the E080 is notably quiet, the E100 is not: it’s rated at 55 dBA, ten decibels louder than the E080’s 45, which is the audible cost of moving more air through a bigger space. Under a quiet room that’s worth knowing. On filtration it holds the line with a MERV-8 filter — real particulate filtration rather than a token screen, and finer than the MERV-1 filters some crawl space units ship with. That matters more than it sounds in a crawl space, where part of the point is cutting a dusty, musty environment rather than just lowering the humidity number. It’s ductable, so you can pull air from one end of the space and push dried air toward a damp corner, which is where the 280 CFM earns its keep — useful in a large or compartmentalized space where air won’t circulate well on its own.

Cold-weather ceiling and gravity drainage

The E100 is rated to operate down to 50°F. That’s a workable floor for a lot of crawl spaces, but it’s higher than the coldest-rated units in this category, some of which keep working into the mid-30s. If your crawl space gets genuinely cold in winter, a 50°F floor means the unit stops removing moisture on the coldest — and often dampest — days, which is a real limitation on a large-area unit you’re relying on year-round.

Drainage is gravity-only; there’s no condensate pump in the box. That’s fine if you have a drain the unit can sit above and run tubing to, and an added cost and some install planning if you need to lift water to a drain point. At 64 pounds in that larger cabinet, confirm your access and clearance before committing.

Headroom that works versus headroom that idles

There’s a practical reason not to reflexively reach for 100 pints, and it’s about how the capacity actually gets used. Think of the E100’s extra capacity over a smaller unit as headroom. In a genuinely large space, that headroom is what lets the unit hold a steady humidity target without running flat out — it has margin to recover after a humid stretch or a door left open. In an average-sized space, though, the same headroom mostly sits idle: the unit reaches the target quickly and spends its time waiting, so you’ve paid for capacity the space never calls on. Neither extreme is what you want, which is why sizing to the space — not to the biggest number on the shelf — is the whole game. (If the humidistat mechanics of that trade-off interest you, our review of the larger E130 walks through how an oversized unit short-cycles.)

That’s also why sizing and operating cost are really one decision. An undersized unit runs closer to continuously, which shows up on the electric bill; an oversized one costs more upfront and cycles more than it needs to. Reported monthly running costs for residential-scale dehumidifiers commonly land in the $10–$30 range, with unit size a real driver of where you land — so the honest goal is matching the E100’s capacity to your actual space rather than treating its big coverage number as a free upgrade. Our operating cost calculator makes that math concrete for the E100, since its ENERGY STAR annual energy figure lets us compute a real seasonal cost — so you can see directly how right-sizing versus oversizing plays out on the bill rather than guessing at it.

Who should NOT buy the E100

Skip it if your crawl space is average-sized — you’d be paying for 5,500 sq ft of claimed coverage and 100 pints of capacity you won’t use, when the E080 or a smaller unit fits the job. Skip it if the space runs cold in winter, where the 50°F floor is a genuine constraint that leaves the unit idle on the coldest, dampest days, or if noise under a quiet room is a priority, since 55 dBA is on the louder side. Its lack of an included pump also matters if your drainage needs a lift. Running cost, though, isn’t a reason to skip it: its ENERGY STAR figure gives you a verified number to plan around.

Our take on the E100

The AprilAire E100 is a high-coverage, well-filtered crawl space dehumidifier for genuinely large spaces — a straightforward step up from the E080 in the same cabinet, and like the E080 its ENERGY STAR certification gives you a verified, measured energy figure to budget against. The real reservations are that it’s louder than its smaller sibling and no more cold-tolerant, with the same 50°F floor. For a big crawl space that doesn’t freeze, with drainage you can handle by gravity, it’s a capable pick — just size the space first with the sizing calculator, and don’t buy the coverage headline if your space doesn’t need it.