Smart Window Energy Recovery Ventilator

Your bedroom needs fresh air. Opening the window doesn't work.

Too hot. Too cold. Too loud. Too humid. Pollen, smoke, a busy street. So the window stays shut, CO2 climbs past 1,500 ppm overnight, and you wake up foggy with a headache.

SWERV sits in your window and fixes it: fresh filtered air in, stale air out, ~85% of your heat and AC kept inside. No contractor. Renter-friendly.

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Ships the week of September 28 · 19 of 50 slots left

Designed & Assembled in the USA
30-Day Free Returns
10-Minute Install
Renter-Friendly & Portable

Graph showing CO2 levels overnight with and without SWERV technology for two people sleeping in a closed room.

SWERV Window Mounted ERV Installed into beautiful white window organic with plants and an Aranet 4 air quality sensor to improve CO2 levels inside without wasting heat

How it works

Exchanges stale indoor air for fresh outdoor air with energy recovery.

INSIDEyour room

Room air 70°F 50% humidity Air delivered 64°F 48% humidity

Cutaway of the SWERV unit mounted in a window, wood front facing the room on the left, showing the quiet fans and ceramic energy-exchange core

OUTSIDEoutdoors

Outdoor air 27°F 20% humidity Outdoor air 27°F 20% humidity

Exhaust — stale room air pushed outside, every 45 seconds Intake — filtered fresh air pulled inside, every 45 seconds

Energy recovery mode

Reduce CO2 in your bedroom without opening windows

Closed windows wake you up foggy with a headache. Open windows waste energy and comfort, letting in heat, humidity, cold, smoke, pollution, pollen, and noise.

Customers with CO2 monitors routinely measure overnight drops of 600+ ppm.

And because SWERV recovers ~85% of the energy an open window throws away, it can pay for itself in 1-2 years.

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Diagram of features including a powerful quiet fan, high-efficiency ceramic energy exchange core, sleek rotary dial, easy access MERV 13 air filter, thick foam insulation, and finished bamboo front panel.

Real customers, real CO2 numbers

Remington A.

It's been incredible. CO2 averages around 400-600ppm throughout the house with one unit at 26-40%. We were only able to achieve these levels if we were both out of the house at the same time.

My girlfriend and I have been able to do hard workouts on our Tonal for weeks without feeling sick. It's the first time I feel like I can actually use it again.

Paul N.

After cooking, CO2 comes down in under an hour instead of the 3 to 5 hours it used to take. Hallway smells barely register now, and the apartment just feels fresh with no lingering odors.

My peace of mind has improved, and smells bother me a lot less than before.

Josh

The SWERV beta unit has had a significant and noticeable impact on air quality. Before, our bedroom was peaking at over 1900ppm CO2. The average CO2 after install is now 784ppm.

We have had much better sleep overall. The most notable change is that we rarely have headaches when we wake up. The reduction in headaches alone has been amazing.

Drew R.

My windows are open a lot less now, and it even seems to slightly reduce my AC runtime. While I was away with it running at 40%, my CO2 stayed around 500 to 650ppm.

Blake M.

I now maintain between 600-800ppm with all the windows closed and my home is much quieter and cleaner.

The big change has been having a quieter environment. It also gets pretty cold here, but the ERV has allowed me to control the indoor climate much more effectively than before.

Jesse M.

Before SWERV I ran a big fan at max all day, which meant a humidifier in winter and a dehumidifier in summer. Now my humidity stays stable without any of that, and my mini split keeps the house cool even at 90 degrees and 80% humidity.

It's doing a good job, and with a second unit I think my problem would be completely solved.