Infrared Thermometer
At the start of this winter I put glass fibre insulation into my ceiling to improve the efficiency of my heating. This got me thinking about what else could be done to reduce heat loss around the house. Knowing where the most heat loss is occurring is the first step to preventing it. My initial thoughts for finding heat loss were of an Thermal Camera. These allow you to see heat as different colours on a screen with blue being cold and red being hot and the rainbow spectrum in between. Like this:
There were two problems with using a thermal camera. The problem first is that the cheapest IR camera I could find is $5000 and renting one for just 2 days is $400. I can justify wasting money on all kinds of toys but I simply cant spend $5000 on such a limited use item no matter how much fun it would be. Renting one might be an option if it would save me some money in the long run but it is doubtful that I was going to find any significant savings as a result of the camera. My whole heating bill for the winter is only $300 and I think I heat a lot. The second problem is that the previously mentioned “cheap” camera has a display resolution of 80 x 80 pixels. At that resolution a photo of anything is this size:
While this size is fine for seeking out hot-spots and photographing them, it's a little unsatisfying that this is all that you get for 5k.
My attention then turned to this:
A Dick Smith Electronics Infrared Thermometer with integrated LASER pointer. At a price of $100 from DSE.
It's a hand held IR thermometer with built-in laser pointer. It works by simply pointing at an object or surface and pushing the button. This will cause the temperature to be continuously displayed on the digital screen. That means if you point it at a hot barbecue plate and then move it to point at the ground the display will show a high temperature and then quickly update the screen to show a lower one. This continuous update feature means its quite good at finding hot spots or heat leakage in my house.
The sample area of the sensor is dependent on how far the sample surface is from the thermometer. The sampling area is basically a circle with a diameter that is 1/8th the size of the distance of the surface is from the thermometer. For example, if the thermometer is 80cm away from the object it is measuring, the sample area will be a circle with a 10cm diameter. Its explained fairly clearly with this diagram on the side of the thermometer.
This means that you have to hold the thermometer quite close if you want to find the exact source of a hot spot.
The thermometer also comes with a convenient integrated laser pointer to clearly indicate where it is that you are getting a reading. It isn't too hard to work out where your temperature sample area is without the laser but it does give a pleasing level of certainty. In reality, there is no way to know exactly how far out of alignment the laser is with the thermal sensor but it is close enough for it not be be an issue, especially given how quickly the sample spot increases when object is a little further away. The laser is useful enough by itself as a child's toy or cat entertainer and the shape of the thermometer lends itself to science fiction fantasies of a ray gun complete with red trigger, laser dot and back lit digital display. It's already got plenty of usage as a toy for a 3 year old.
The laser and the display back light can be switched on or off at will and the display can show both Fahrenheit and Centigrade temperatures. Holding the trigger will give constant temperature updates and releasing the trigger will display the last sample taken for 15 seconds before turning off, which is long enough to show a by stander the sampled temperature while still saving the battery. The battery is a standard 9 volt, the same type that goes in a household smoke detector. Battery life is enormous. After hundreds of temperature readings and several long sessions as a child's toy, it's still going strong on the original factory supplied battery. It even comes with a black vinyl pouch for storage that is belt attachable and looks very holster like.
As a thermometer, it seems to be quite accurate. I have a continuous flow hot water system that allows me to dial in a temperature of hot water and then turn on hot tap to get that temp water. A bath filled with 39 degree (Centigrade) water gives a reading of 39.2 degrees. Boiling water shows 99.7 degrees.
Taking the temperature of some things is a bit of an eye opener. Pointing it at the sky on a hot summers day shows minus 5 degrees. The black barbecue cover in the sun is 95 degrees and even though it feels hot to touch, you can place your hand on it without too much trouble . When the barbecue is running, the hot plate gets to about 180 degrees. The local heated pool where they claim the water temp is 30 degrees shows 30 degrees. Once you are comfortable with the fact that you are a nerd carrying an IR thermometer around, there is a world of wonder to be sampled.
The original purpose for buying the thermometer was to find heat wastage in my house and for this purpose, it has worked out fairly well. I identified two areas for attention. I installed a draft blocker on the front door and I am going to install some under floor insulation in my wooden floor boarded house. The great thing is that I can measure the effect of these changes which makes any improvements made far more satisfying when they can be verified scientifically as being effective.