The only thing that can potentially detect vape is smoke alarms. However, smoke alarms are specifically designed to spot cigarette smoke and not e-cigarettes. E-cigarettes or vaping devices create vapor instead of smoke. Smoke alarms can easily detect smoke compared to vapors. Despite this, smoke alarms can still see vape when you blow steam directly into it. The reason behind this, detectors or alarms is sensitive to minute airborne particles. Smoke alarms are being triggered when these small particles disrupt alarm electricity It is also the reason why no smoke alarms are installed in hotel bathrooms. The steam from the hot shower can trigger the smoke alarm. In the case of a fire alarm, vaping cannot start a fire alarm.