Real Customer Stories + CO2 Data
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.
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.
Jeff D.
No longer a tradeoff, good and fresh air year round with more comfortable temperature gradients without constantly managing it all day.
I now have good quality air without thinking about it all day long. Just turn it on!
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.
Michael J.
CO2 levels stay lower overnight.
Air feels fresher.
Chris S.
Install was straightforward. Even with three people and two dogs in the room and the windows closed, it held CO2 around 1000ppm. I'm looking forward to really putting it to work once it's too hot to keep the windows open.
Eric S.
It brought in fresh air, and the install was easy. It went right into the window with no modification, and the instructional video was helpful.
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.
Gene W.
CO2 is consistently in the good range. I'm thrilled with how effortless this product is even running 24/7/365.
Swerv normalized my environment with constant true ERV filtered air. Once installed, Swerv is effortless. All you do is set it and forget it. There's no going back for me.
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.
Siddha T.
After turning power up to 100%, the air doesn't feel stuffy anymore and CO2 is consistently well under 1000.
My sleep and general mental performance is better.
Matt C.
CO2 can be kept below 1000 ppm. Also helps eliminate particulates.
General improvement in air quality.
Ilan R.
I'm now able to have a lower CO2 environment on days where I have to keep my windows closed.
I'm better at critical thinking on days where my windows have to be closed.
Herb R.
When temperatures and humidity are mild I put the switch to fresh-air mode and we get fresh air at minimum noise, and it's adjustable. When it gets hotter or colder I use ERV mode and we get fresh air while recovering energy.
I feel a bit fresher and better rested in the morning since the unit is in the bedroom. It probably is helping me sleep more comfortably.
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.
Frequently Asked Questions
What is SWERV and how does it work?
SWERV is a window-mounted ERV (Energy Recovery Ventilator). It brings fresh air into your room while recovering the heat that normally gets thrown out the window with ventilation. The fans exhaust stale room air through a ceramic core, which captures the heat on the way out. Then the airflow reverses and fresh outdoor air comes in through the warmed core, picking that heat back up. This cycle repeats every 45 seconds or so, giving you continuous fresh, filtered air without losing your heating or cooling energy. ERVs are standard in modern high-performance buildings, and SWERV brings that same technology to a single room with no ductwork or construction.
How is it different from an air conditioner or air purifier?
Both of those recirculate the air already in your room. An AC cools it but brings in nothing fresh. A purifier filters out particles but can't remove CO2 or the odors that build up overnight in a closed bedroom. SWERV actually exchanges stale indoor air for fresh outdoor air, filtered through a MERV 13 filter, while the core keeps your heating or cooling energy inside. It works alongside your AC or purifier, not in place of them.
Will it fit my window?
SWERV fits double-hung, single-hung, and horizontal sliding windows at least 23" wide, with at least 6" of opening height. Windows wider than 48" work too, just email us at austin@swervair.com and we'll send extra foam blocks. The window needs to open and close smoothly and have a solid frame and sashes. Not supported: casement, awning, or tilt-open windows, doors, or any opening that can't be securely closed onto the unit.
How loud is it?
That depends on fan speed, which you control with the dial. At sleep-mode speeds the sound is steady airflow noise rather than a mechanical hum, and it drops as you turn the dial down. Max mode is noticeably louder and meant for short bursts of rapid air exchange, not overnight use. Quieter operation is the single biggest focus of our next revision, so your feedback on real-world bedroom noise is some of the most valuable input you can give us. (A calibrated dBA figure is still being tested and will be added once we have reliable measurements.)
How easy is it to install?
Much easier than a window AC. A window AC is a 50 to 80 lb two-person job with brackets and screws. SWERV weighs about 19 lbs, about as much as a countertop microwave, and installs more like a window fan: set it on the sill, close the window down onto it, done. Most installs take about 10 minutes, one person, using tools you already have (a sharp knife, cutting board, scissors, and a ruler). No drilling, no screws, no permanent modification. The one step that takes care is trimming the two foam side blocks to length, since a straight, square cut is what locks the unit in and seals it. The installation guide walks you through it.
How much energy does it use?
Very little. At typical operation it draws about 10 watts, roughly the same as a Wi-Fi router or an LED bulb. Even at max speed it's just 42 watts, less than most laptop chargers. Running it all night costs about a penny at average US electricity rates, or a few dollars per year.
What does "beta" mean, and what's expected of me?
SWERV is a new product in early production. Beta units are built in small batches, and we use this phase to gather real-world data across many homes, windows, and climates before finalizing the design for full-scale manufacturing. You get early access and a direct line to the engineering team. In return, we ask that you read and accept the Beta Program Agreement before use, follow the installation guide carefully (including staying present for the first 10 minutes of operation), and share honest feedback: what works, what doesn't, and anything that seems off. If you hit an issue, contact support with your order number, photos, and a short description.
How often should I replace the filters?
Check the pleated filter every 30 days for the first few months to learn your environment's dust load. Replace or clean it every 6 to 12 months, or whenever there's visible buildup. Wipe or wash the removable stainless steel outdoor pre-filter every 6 to 12 months as well.
Will replacement filters still be available years from now?
Yes, and it's a fair thing to ask an early-stage company. The SWERV filter is custom to the unit rather than an off-the-shelf size. We tested filters from more than 20 manufacturers before choosing this one because it gave the best combination of MERV 13 particle filtration, activated carbon, high surface area, and low pressure drop.
We hold a large inventory and sell replacements on our site. If SWERV ever stopped supplying them, we would tell customers directly, release our remaining stock at a steep discount or free, and give owners the specifications and manufacturer contact needed to order compatible filters straight from our filter partner. You would not be left with a unit you cannot maintain.
We're also exploring a washable prefilter that never needs replacing and only gets rinsed every 3 to 6 months. It wouldn't capture smoke, pollen, or odors the way the current filter does, but it would be another path to keeping the unit running.