If you are one who happens to love the smell that the REME HALO®/VirenKiller HVAC produces throughout your home or work place, you may feel as though it has stopped working when you can no longer smell it. It's ok! It is still working! Rest assured that if the indicator light is on, your system will continually provide over 2 years, or over 25,000 hours of fresh, clean, purified air.