12 Different Kinds of Smart Home Sensors (Everything You Need to Know!)

Looking through all the different kinds of smart home sensors and starting to feel overwhelmed? I certainly did.

Lucky for you, I spent hours researching the market to come up with a comprehensive list of all the different types out there.

I hope it helps to clarify things a bit.   

Different kinds of smart home sensors: the list

In short, here are all the different kinds of smart home sensors available today: 

Before we go into more depth comparing these different kinds of smart home sensors and identifying their applications and advantages, I want you to take a deep breath.  

Relax.

There is a lot to consider before making a smart sensor purchase. But once you’re equipped with the knowledge I promise it is not that complicated! 

Read this post in its entirety and all your questions will be answered. 

OK. You good? I’m good. Good. Let’s move on.

Standalone smart sensors vs multipurpose smart sensors

Many of different kinds of smart home sensors are sold as stand alone products. In most cases, it simply doesn’t make sense to buy a product that only does one the functions detailed above. 

I made this mistake early on in my home automation journey. Ultimately I ended up either returning or not using the “standalone” products. 

The reason is simple – most new smart home products on the market today have several of these sensor capabilities built in. They are multipurpose products! 

For example, one of my favorite multipurpose sensors is the Aeotec Multisensor 6. It’s a motion, temperature, humidity, light, UV, vibration sensor!

If your interested in purchasing the Aeotec Multisensor 6, you can buy it here on Amazon.

That said, standalone sensors do have their place.

Additional considerations before buying smart sensors

Before detailing the applications of each type of smart sensor, here are some additional things to consider before making your purchase.

• Hub/Bridge requirements – hubs simply connect all your devices together. If the smart sensor you’re buying only requires WiFi and you’re not interested in integrating it with other products in the future, you likely don’t require a Hub. But in most cases you’ll want to make sure you own the correct Hub that works with the product. (Some examples of hubs: Amazon Alexa, Google Home, Samsung SmartThings) 
• Protocol compatibility (often referred to as interoperability) – Your device leverages a certain “protocol” in order to communicate and integrate all of your smart devices. Make sure the smart sensor your buying is compatible with this protocol. A lot of times the product will just list the Hubs that it works with – this is enough information for you to make a purchase.  (Protocol examples: WiFi, Bluetooth, Z-wave, ZiggBee)
• Range – this is typically measured in feet and is largely dependent on the type of smart hub/protocol you are operating on. In the event you want to place your sensor somewhere out of range there are a variety of range extenders that can resolve this issue.  
• Battery Life – how many years until you need to change the batteries on this device? If the device is strictly WiFi based it’s likely your battery life will be much shorter than a similar device that leverages a protocol like Z-wave or ZiggBee .
• Indoor vs. Outdoor use – this is an important one. Most smart sensors on the market today are not necessarily meant for outdoor use. Be on the look out for this depending on your application. 

Still OK? Good.

If you’ve been shopping for a bit you realize the smart home sensor market, and the smart home market more generally, is extremely fragmented. 

That’s because a single smart home protocol (or “standard) for these products to communicate does not currently exist.

As a result companies leverage different protocols to operate and connect their devices, resulting in products that simply don’t work with each other.

That said, look out for the considerations I detailed above and you’ll be just fine.

OK, now each type of smart home sensor in more detail:

1. Contact sensors

Simply put, a contact sensor tells you whether something is “open” or “closed”. 

I use quotations because as you’ll see in a moment, there are tons of unique applications besides just whether something is open or not. 

Typically these sensors consist of two pieces, both easily installed. 

When in the “closed” position the two pieces of the sensor are in close proximity to each other. 

When “opened” the pieces are further away. 

The most obvious application and advantage to this sensor is for home security. 

You can install contact sensors on doors – one piece on the door jam and the other on the door itself. This gives you the ability to be notified when a door is opened or closed. 

Once you get more advanced you can use this information to trigger additional actions based off of the open and closed status of the door (like turning on the home lights). 

Similarly you can use these sensors on windows all throughout the house to stay informed about which windows are open and which are closed. 

Beyond security applications I’ve read about homeowners placing these things in their mailbox – one piece of the sensor on the door of the mailbox, the other on the inside of the box. 

When the mailbox door is opened it sends an alert to the owner that their mail has been delivered. 

“You’ve Got Mail!” 

I’ve even seen homeowners use these sensors on their dial timed washer/drying machines.

By placing the sensor on the dial you can get a sense of when the laundry is just about done instead of having to check in on it every 20 minutes! 

2. Motion sensors

Smart motion sensors have a variety of security applications for detecting motion and alert homeowners when they are away.

They can also be used to trigger home automations, like turning on/off the lights when someone walks into, or out of a room.

In my experience most smart home security systems have motion sensors built in and you can leverage these motion sensors for other home automations. 

For example I have a Blink security camera on my back deck that has a motion sensor built in. If that camera detects motion anytime past 10PM not only will the camera start recording but it will also turn on my back deck light! 

The idea here is two fold – 1) Light up the perpetrator so I can better see them on the camera that’s recording and 2) Hopefully alarm/startle the perpetrator enough so that they leave quickly. 

There are many more outdoor applications involving triggering lights on and off when people walk around the proximity of your home or property. This can be a good security measure and just nice to have at night. 

3. Vibration sensors

Most applications of vibration sensors involve detecting knocking on a door. 

The concept being if someone knocks on your door, but doesn’t open it, you can still be alerted. 

I’ve also read some homeowners placing these by their door bell chime so that whenever the doorbell rings (in case someone decides not to knock) the vibration from the chime triggers this sensor to alert you.  

In addition to door/doorbell applications these sensors can be set up on windows to alert you of a break-in. For example, in the event that a home intruder breaks a basement window, this sensor would trigger an alert to your phone. 

Lastly try placing these on a washer or dryer to alert when cycles start and end. 

Make sure you read the specific product reviews however as not all vibration sensors will be sensitive enough to pick up these subtle variations. 

4. Sound sensors

Sound sensors come in a few varieties. Some “listen” specifically for high-pitched, alarm sounds. Others listen for noise at certain thresholds for extended periods of time. Let me explain. 

I’m personally toying with the idea of buying some of the “high-pitched sound detection” sensors and placing them around my house next to my existing (non-smart) smoke and carbon dioxide detectors. 

By doing this I will avoid having to replace all the smoke/carbon dioxide detectors in my home and I will still get alerted when/if they go off. 

This provides peace of mind when you’re on vacation that your house is still standing

As mentioned previously, other sound sensors measure volume at certain thresholds over a specific period of time. 

One obvious application is for detecting a party. If you’re a homeowner that rents or uses Airbnb this sensor could save you hundreds, if not thousands in fines and home repairs.

The idea being that if your guests are making a lot of noise (crossing a predefined noise threshold) for an extended period of time, you will be alerted. 

This gives you the chance to reach out to your current tenant/renter and ask them to quiet down before things escalate.

That way your friendly neighbors will remain your friendly neighbors.  

5. Water/leak sensors

These sensors alert you of excess water build up and moisture to help you prevent leaks and water damage. 

Talk about the potential to save you a tremendous amount of money.

Did you know that 98% of all basements will experience water damage during their lifetime. 

That is an incredible stat.

What that means for you and I as homeowners is: it’s not if we get water damage, but when. 

That’s why I think a water sensor should be among the first smart device purchases you make. 

What’s more is you can integrate additional smart products to “react” to the water sensor going off. 

For example if you have a smart water valve and a water pump plugged into a smart plug you could trigger both whenever the water sensor is triggered.

This way the water gets shut off and your water pump gets turned on. Pretty effective response time. 

Other water sensors get much more involved and can monitor your homes overall water consumption and even monitor/control your water irrigation needs. 

6. Temperature/humidity sensors

Temperature sensors are useful both indoors and out.

I have three of these throughout my home since it currently can’t support a smart thermostat. 

This allows me to get alerts if say the temperature in the basement falls below a certain threshold (anything to avoid frozen pipes!).

I also get alerts if the temp goes too high. I’m looking at you, wife 😉

The humidity sensor can be pretty handy if you have humidifiers and dehumidifiers in the home. 

For example, in most homes the humidity is highest in the basement – the higher the humidity, the more moisture the air is saturated with.

By getting a smart humidity sensor you can plug your dehumidifier into a smart plug and trigger it to be turned on whenever the sensor is triggered by high humidity, reducing the moisture in your basement. (Some dehumidifiers have “sensors” built in but they are very often inaccurate)

Another obvious use case for temp/humidity sensors is simply gathering outdoor readings.

7. Light/UV sensors

These types of sensors, in my opinion, are not all that useful – or common for that matter (not a coincidence I imagine).

UV sensors measure the amount of UltraViolet rays from the sun. 

I’ve seen these sensors as both home products and wearables. 

The wearable tech is not really all that practical – how many people do you know who will go through the trouble of buying a UV sensor that attaches to their clothes to measure sunlight? 

Similarly the home product measures UV rays in your immediate environment (wherever the smart UV sensor is placed). 

I guess these can help to better inform you when sunscreen should be applied but until this tech is simply incorporated into a smart watch or some other, more fashionable wearable, I don’t see them taking off. 

8. Smoke/carbon dioxide sensors

Smart smoke/CO2 detectors can be a fairly expensive proposition for homeowners who would have to replace all their existing devices.

I still think the most cost effective thing to do here would be to buy a few smart sound sensors and place them next to existing smoke/CO2 detectors.  

But for those so inclined the “truly” smart smoke/CO2 detectors have some pretty neat functionality. 

For starters you can more easily monitor the battery life of each individual device. If you’ve been a homeowner for any period of time you’ve probably had the experience of one of your detectors beeping due to low battery. 

Good luck figuring out which one!

With smart smoke/CO2 detectors you’ll be able to see clearly within an app exactly which one needs to be changed and even get notifications well before that alerting you of an upcoming change. 

In addition most have built in speakers. Once one of the devices is triggered they all will announce in unison what the danger is (smoke or CO2) and the problem location/room. This is incredibly helpful.

And while the primary use case is safety, many of these products include the ability to play music throughout the house. 

Surround sound baby! 

9. Radon sensors

Whether you’re a homeowner or not you’ve probably at least heard of radon gas. It’s a colorless, odorless, tasteless radioactive gas. 

How fun! 

As uranium naturally breaks down in soil, rocks and water radon gas slowly exits the ground and can enter into your home through foundation cracks/holes. 

It typically builds up in the basement but even homes without basements are still at risk of radon contamination. 

Why does this matter? Well this gas-hole causes lung cancer. 

When you buy a house you have the option of performing a radon test during the home inspection but many people skip it.

Even those that have the inspection done are not completely out of the woods as radon levels are constantly changing. 

This device helps to consistently monitor radon levels year round, ensuring that you home is at a safe level. 

10. Air quality sensors

There is a bit of overlap here with some of the other gas sensors we’ve discussed above but I list smart air quality sensors separately because of their versatility. 

In addition to temp, humidity, and C02 these things can monitor dust, toxins, nitrogen dioxide, ozone, air pressure and more.

If you’re like me and you have allergies or asthma the air quality of your home has a really big impact on your quality-of-life. 

It is possible your home is the very thing that is making you unwell – and keeping you unwell.

These devices help to monitor your air quality so that when things start to get out of balance you’re notified. Once you have the specific information about the problem you can take direct actions to start solving it.

And what’s better is they can integrate with your other smart devices. 

Imagine this – your smart air quality sensor detects that dust levels in your bedroom have risen to an unhealthy level. 

This alert automatically triggers your smart vacuum cleaner to start cleaning your room and your sent a notification as a reminder to recheck the dust levels after the vacuum finishes up. 

Not bad.

11. Electricity usage sensors

Electricity Usage sensors are not really for the newbie just starting out in home automation tech. 

They involve some wiring work at your electrical panel and for most that’s enough for people to move on. 

That said, they can be really useful.

Once installed, at a very basic level, electricity usage sensors track how much electricity you’re using. Uh, Duh.

Beyond that they can identify different patterns in your energy usage so that you can be aware of them and then make changes to be more efficient. 

You can even set alerts for critical home devices going on or off like sump pumps, well pumps or flat irons. 

In reality these sensors are probably best for home owners who live a part of the country where their electric bill is dependent upon hourly usage totals. 

For instance in Arizona many households are charged for each hour of electricity usage between 3PM and 8PM.

For these homeowners knowing, and then adapting their peak usage times can be a real money saver. 

12. Location sensors

9 times out of 10 your mobile device serves as your smart location sensor.

Most smart hubs are able to leverage you and your families’ phones to detect mobile presence.

You can then use this information to trigger certain home automations.

For example – automatically unlocking the front door when you get home or turning on the front lights. 

The problem with this approach is that mobile presence from your cell phone is not always reliable.

Things like physical surroundings, atmospheric conditions, Wi-Fi, your phone’s native capabilities and battery life can all negatively impact location readings.

To combat this there are standalone smart location sensors on the market. 

Unfortunately most require that you have a compatible smart hub and that you carry them with you.

That’s a bit inconvenient. However, depending on the automation you’re looking to set up, it could be a worthwhile trade-off.

Take this idea for example – I’ve read in pet forums that some owners put these devices around their dog’s collar. This allows them to get notifications whenever the dog enters or leaves a specified area. 

Summary

There are a lot of different kinds of smart home sensors out there. As a result you should have a good understanding of the automations you’d like to implement before making a purchase.

I’ve always found it most helpful to first think of the automation and then work backwards to determine what devices I will need to implement it.

If you’re still looking for a reason to dip your toes in this technology – think of many of these different kinds of smart home sensors as an insurance policy on your home.

For 20 dollars or less you can potentially prevent thousands of dollars of damage or theft.

Good luck and enjoy.