But what I really wanted it for is to see how well - or poorly - insulated our new house is. So I waited until it was freezing outside, then turned the heating on to max for an hour, then went outside to see whether there were any obvious leaks.

First thing was a long shot of the property - with an LED streetlamp in the foreground.

It's good to see that the camera can pick up the heat of the lamp. I'm not really interested in whether the readings are completely accurate - I just want to make sure that the camera can discriminate relative temperatures. From this perspective, things are looking good! The property's walls are a fairly uniform temperature. There are no prominent hot-spots where the radiators are. The windows, naturally, are slightly warmer. But not massively.

Let's take a closer look at one of the windows:

This is fairly typical of our windows. I was glad that there weren't huge leaks all around the edges. But the tops of each window had a thermal disparity.

So it might be worth replacing the UPVC seals, and re-doing the sealant around the edges.

The back of the house was slightly different:

On the top right is a hot-spot - that's the flue from the boiler. The hot "line" is the drainpipe which acts as the overflow from the boiler, I think. The hot circle is the exhaust hole for an extractor fan. It looks like the wall is very thermally leaky - but I think that's a quirk of the camera. As I panned down, I got this image:

That looks much more like I was expecting. But let's pan down to ground level: As expected, there's a bit of escape around the back door - but what's that hot-patch near the ground? Zoom! Enhance? That's the vent for the tumble-drier. Not really a huge amount I can do about that. Hot air and moisture need to esape. There's a similar warm patch on the left of the image which is our Rediffusion Junction Box.

Thoughts

This was a quick experiment. The camera - and it is a cheap addon - isn't always great at telling temperature, especially at a distance. For some "quick and dirty" visualisations, it is pretty good. But I suspect I'd get better clarity and more information out of a more expensive model.

I'm hoping that when / if the temperature drops to below freezing, and the heating has been on longer, I'll get a better idea of how our insulation is working. I'm also toying with the idea of taking thermal images of the houses around me. Although I'm not sure of the legal / ethical implications of publishing them!

The Seek Thermal is a curious beast. While you can buy Android phones with built in thermal cameras, and dedicated devices, this is an add-on. Plug it into your existing phone, download an app, and off you go. In theory!

Here's a quick selfie!

Why a selfie?

It's backwards!

If you get the USB-C version, you can plug the camera in for either direction. Great! If you have the micro-USB version, you're stuck in selfie mode. Boo!

Quite why Seek decided to put the connector on this way, I have no idea. There are only a handful of phones where this orientation makes sense.

Improvise Adapt Overcome!

I picked up a cheap OTG adapter. Note: make sure that it is a sync or OTG adapter. Otherwise the camera won't work.

A bit ramshackle, but it works!

Here's a photo of my wife drinking a hot cup of tea.

Photos are 960x1280 resolution and about 600KB - so won't take up too much space on your phone. Weirdly, images are stored in /Pictures/Seek Thermal/ rather than the more normal /DCIM/ folder.

Accuracy

Here's a photo of a mug of boiled water and an ice-cube tray.

That's pretty good! To be honest, I'm not using this for precise measurements - I'm looking for thermal disparities. You can set it to Celsius, Fahrenheit, and Kelvin.

App

The Seek Thermal app is a little basic. It works, but isn't great to look at. It mostly links to lots of videos on how to use it.

You will need to set your device to USB OTG mode - and give the app permission to talk to the camera.

You can choose a variety of overlays - including max and min temperature. You can also add location metadata to the photos and, for some reason, the camera serial number.

If you don't like the default colour palette, that can also be changed.

Usage

Again, basic but workable. The camera makes a constant clicking noise while in operation. Apparently that's normal - but sounds a bit weird. You're unlikely to take surreptitious photos with it. Their FAQ says:

There’s no need to worry, this is simply the noise your camera makes while you are shifting it between different fields of view. The noise you are hearing is the camera focusing and calibrating the image to achieve the highest resolution possible.

There is a manual focus wheel on the camera. It seems to adjust the picture, but I'm not sure how yet.

Video

It also does video.

Apparently, the frame rate is restricted to 15fps due to international munitions sanctions...!

Compare and Contrast

This is a cheap camera. Here's what an expensive FLIR camera produces:

Terence Eden is on Mastodon

@edent

Thermal Imaging Selfie!
Have serious professionals here measuring the house's heat flow. Have borrowed their Android (!) FLIR camera. pic.x.com/Q1CRyeTyvI

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That's much clearer - but about twice the price. Speaking of which...

Cost

About £260 for the micro-USB version. If you want higher resolution, expect to pay significantly more.

Youch!

Verdict

This is a bit of a luxury purchase. If you want to see where your house is losing heat, or if there's a hot wire in your walls, or if your radiators are heating up - it's a cool gadget. The app is a bit basic, but works.

Being able to tell the body temperature of strangers leads to some interesting privacy questions.

Would I pay full price for this? No. But if you can pick one up second hand, or borrow one from a hackspace, they're fun and useful. As winter draws in, I'm going to be seeing just how good our home is at retaining heat.

Thanks

Many thanks to Brie for the generous gift.