How to choose and wire a reliable remote temperature sensor for your Home Assistant setup

As of 2025-10-14, I’ve been quietly tinkering with something that might help you stay on top of heat and humidity around hand-made equipment—like a hay steamer for horses. If you’re after a reliable remote temperature sensor that you can drop into Home Assistant, here’s how I approached it. It’s not about chasing the latest gadget, but about finding something practical that gives you steady data and sensible alerts.

Why a remote temperature sensor matters

Situations like steaming hay can push ambient conditions up or down in surprising ways. A remote temperature sensor lets you watch trends without standing right next to the steam, so you don’t have to guess whether things are cooling or getting too humid. With Home Assistant, you can log the readings, see them on a dashboard, and set automatic alerts if things drift outside a safe range.

What to look for in a remote temperature sensor

When you’re hunting for a good sensor, a few basics make a big difference:

• Temperature and humidity range: Make sure the sensor can handle the range you expect in your space. If you’re monitoring around a hay steamer, you’ll want something that can cope with higher ambient temps and high humidity without clamming up.
• Connectivity: Wi‑Fi devices (like Shelly H&T) are easy to wire into Home Assistant, but you might also find Zigbee or MQTT-based options that fit a broader smart-home setup.
• Power and maintenance: Battery-powered sensors are easy to install, but you’ll want to know how long the battery lasts and whether you’re comfortable changing it. Some setups use a small power brick for more permanent placements.
• Enclosure and mounting: Steam and splashes aren’t friendly. Look for IP-rated enclosures or plan to add a protective housing that still allows accurate sensing.
• Integration with Home Assistant: The easiest path is a sensor that works out of the box with Home Assistant’s Shelly integration or MQTT bridge. That reduces the setup friction and helps you start logging data quickly.

For a straightforward path with good community and support, a dedicated Wi‑Fi sensor like Shelly H&T is a solid option. It measures both temperature and humidity, and it can feed data directly into Home Assistant.

If you prefer a DIY route, you can use a precise digital sensor such as a DS18B20 or Sensirion SHTx family with an ESP8266/ESP32 and MQTT. That approach gives you flexibility and often lowers cost, but it takes a bit more setup.

External reference: Home Assistant’s Shelly integration docs explain how to connect Shelly devices to your dashboard (great for getting started quickly): https://www.home-assistant.io/integrations/shelly/ . If you want to peek at the official Shelly product, their Shelly H&T line is described here: https://shelly.cloud/products/shelly-h-t/.

Smart options that play well with Home Assistant

• Shelly H&T (Wi‑Fi) with temp and humidity sensing. It’s designed to live on your local network and integrates smoothly with Home Assistant through the Shelly integration. It’s a good choice if you want a single, reliable device that just works.
• DIY ESP-based sensors with MQTT. A DS18B20 temperature sensor (and optionally a humidity sensor) on an ESP8266/ESP32 can talk MQTT to Home Assistant. This is flexible and cheap, but you’ll handle firmware, MQTT broker setup, and maintenance yourself.

Why I’d pick Shelly H&T for most folks is simple: you get a compact, weather-tolerant device that talks over Wi‑Fi, and Home Assistant can read it without a lot of extra glue. If you love tinkering and want to tailor a particular space, a DIY MQTT sensor is a fine path, especially if you already run an MQTT broker at home.

How I set this up around a hay steamer

Here’s how I approached a practical setup for monitoring around a hay steamer. The goal wasn’t to measure steam temperature directly (that’s messy and not practical for a sensor placed in the room). Instead, I focused on ambient temperature and humidity around the equipment so I could spot spikes that indicate steam or moisture buildup that could affect hay quality.

• Placement: I put the sensor in a sheltered spot near the steamer but not in direct contact with the steam jet. A small, ventilated enclosure helps keep the device safe without skewing readings.
• Authentication and network: A dedicated Wi‑Fi device sits on the same LAN as my Home Assistant instance. This keeps latency low and data flowing reliably.
• Data approach: With Shelly H&T, readings appear in Home Assistant almost instantly. If you go DIY, set up an MQTT topic for each sensor and use a small dashboard card to visualize trends.

The practical takeaway is simple: you want a remote temperature sensor that you can trust to report steady data. If you notice a sudden rise in temperature or humidity, you’ll have a signal you can act on—like adjusting ventilation, intake airflow, or steaming duration.

Getting it set up in Home Assistant

Once you’ve picked a sensor, the next step is to bring it into Home Assistant:

• Install the Shelly integration (if you chose Shelly): In Home Assistant, go to Integrations, add Shelly, and follow the prompts to discover your device.
• Add automations: Create a simple automation that triggers when the sensor’s temperature crosses a threshold. For example, you can push a notification to your phone or email if the ambient temperature around the equipment spikes.
• Visualize data: Put the readings on a dashboard so you can glance at trends over hours or days.

If you go the DIY route with MQTT, you’ll add an MQTT sensor to Home Assistant and configure a similar automation. You’ll also want to ensure you have a reliable MQTT broker running (like Mosquitto) and a consistent topic naming convention.

External references that help with this setup: Home Assistant’s Shelly integration docs (https://www.home-assistant.io/integrations/shelly/) and Shelly’s product page (https://shelly.cloud/products/shelly-h-t/).

Tips for maintenance and reliability

• Protect the sensor from direct steam while keeping it in the space you’re monitoring.
• Regularly check battery life if you’re using a battery-powered model.
• Calibrate once in a while if you notice readings drifting, especially when you change the room layout or steam duration.
• Have a plan for firmware updates. Shelly devices generally handle updates automatically if you enable them on the device, but it’s worth checking every few months.

With the right remote temperature sensor in place, you’ll understand your space better and avoid surprises. The data becomes a quiet helper you can rely on, not a gadget you forget about.

If you’re curious about the exact path I used, start with Shelly H&T for a ready-made solution, and lean on Home Assistant’s own docs to connect it smoothly to your dashboard: https://www.home-assistant.io/integrations/shelly/ and https://shelly.cloud/products/shelly-h-t/.

As always, I’m happy to hear what setups you’re running and how your space adapts to your own needs. The more you share, the more we all learn.