FAQ

Everything people ask us most about SWERV, the window ERV that brings fresh, filtered air into your room without opening a window. If you do not see your question here, reach out and we will help.

What is a window ERV, and how is it different from a fan or AC?

A window ERV (energy recovery ventilator) actually swaps your stale indoor air for fresh outdoor air, while an energy recovery core holds onto about 85% of your heating and cooling. A fan just moves the same air around, and an AC cools that air but does not bring in fresh outdoor air or lower your CO2. SWERV does both jobs a fan and AC cannot.

Will SWERV actually lower the CO2 in my bedroom?

Yes. Because it brings in fresh outdoor air and pushes the stale air out, it physically removes the CO2 your breathing builds up overnight. One of our beta customers measured their average bedroom CO2 drop by more than 600 ppm. You can read more in our guide to high CO2 in your bedroom at night.

How is SWERV different from an air purifier?

An air purifier recirculates the same indoor air, so it cannot lower CO2 or bring in anything fresh. SWERV exchanges the air itself, which is the only way to reduce CO2, dilute VOCs, and clear stuffiness. It also filters the incoming air, so it does much of what a purifier does at the same time. Full breakdown here: air purifier vs ERV.

What window sizes does SWERV fit?

SWERV fits sliding windows between 23 and 48 inches wide, both vertical (single and double hung) and horizontal sliders. It does not currently fit casement or crank-out windows, or sliders narrower than 23 inches.

How long does installation take, and do I need a contractor?

About 10 to 15 minutes, by yourself, with the included weather-tight sealing kit. No ductwork, no contractor, no renovation.

Is SWERV renter friendly and portable?

Yes. It installs and removes without any permanent changes, so it is ideal for renters, and it is portable enough to take with you when you move.

Does it work in winter and summer?

Yes. The energy recovery core pre-conditions incoming air toward your indoor temperature and humidity, so you get fresh air year round without a big comfort or energy penalty, even when it is freezing, hot, or humid outside.

Can it help with wildfire smoke or a neighbor's smoke?

Yes. Incoming air passes through a MERV 13 and activated carbon filter that captures fine smoke particles and much of the odor, and running SWERV keeps your room at a slight positive pressure that helps push smoke back out. See stopping neighbor smoke and keeping wildfire smoke out.

How loud is it?

Quiet. Typical operation from our first 100 units runs around 35 to 54 dB depending on fan speed, which is comfortable for a bedroom with people sleeping.

How large a space does one unit cover?

One unit is designed for a single room up to 1,000 square feet. You can pair two units over Wi-Fi for balanced supply and exhaust across larger spaces up to 2,000 or more square feet.

What filter does it use, and how often do I replace it?

A 2-in-1 MERV 13 and activated carbon filter that captures smoke, pollen, dust, odors, and VOCs. Each filter lasts roughly 4 to 12 months depending on your air and usage. Replacement filters are always available.

Does it help with mold, humidity, and VOCs?

It helps by diluting humidity, VOCs, and CO2 with fresh filtered air, and its core moves some moisture between air streams. It is one layer of a healthy home, alongside fixing any water sources. More in mold and humidity ventilation.

When will my order ship?

Current batch orders ship between July 25 and September 25, in the order they are placed. We will keep you updated if anything changes.

What is the return policy and warranty?

SWERV comes with a 1-year limited warranty and free 30-day returns. Full details are in the Return Policy and Limited Warranty.