About nine years ago I bought myself an infrared thermometer for the princely sum of $99. That is to say a device that can show you the temperature of an object from a distance. I bought it to see if I could find areas in the house where we were losing heat in winter and gaining heat in summer. It is not a thermal imaging camera, the cheap ones of those are 5 times or more expensive than my little infrared thermometer. It shows you the temperature over a given area,! It is a Digitech QM 7221, but it is somewhat old now and no longer available, a new model has superseded it.
It is easy to operate, it is just a case of pulling the trigger (which activates two lasers that cross) it will then show you the temperature of the surface between the points of the two lasers. I have found the unit to be very useful for the following applications –
• Energy loss and gain in the house – To use the thermometer for this it is just a simple case of running the laser dots over the surface you are interested in (walls, ceiling, floors, inside or out) in a regular pattern and taking note where any temperature anomalies are. Nice and simple.
• Temperature of wood burning stove – we have a wood burner which we can use to cook on or in, and use it regularly during winter. Depending on how things are burning in the firebox and where the flames are, the temperature of the cooking surface can vary somewhat and the IR thermometer helps us identify the hot spots. This is especially useful if we are in a hurry to get cooking. Unfortunately, the oven works by heating the air rather than a surface so the IR thermometer is less effective in this case, but it can tell us the temperature of any pots and pans in the oven, giving us an indication.
• Temperature of steel insert for stored heat cooker – Years ago I made a steel insert for one of our stored heat cookers, to increase the amount of heat available (article here). According to those who know better than me, the cooker, with the addition of the heating plate, can be used to cook bread. Anyway, when placing the hot heating plate (warmed up on the gas stove) onto the polystyrene foam can cause catastrophic failure if it is too hot. In this case the IR thermometer leaves no doubt.
• Temperature of bricks for use in warming bed – one way of warming up the foot of the bed in winter by using heat from the heater, stove etc is to warm up a brick or paver and slip it into the foot of the bed, with or without a fabric cover. We would use the oven part of the wood burner, and again, it is important to know the temperature of your warming brick before your transfer it to the bed. Bingo!
• The seedling germination pad – This is also the subject of a separate article. To assist in early germination of spring seeds like tomatoes, an electric seed germination pad is used to give create the warmer temperatures needed. It can be difficult to know what is going on though, and I found the infrared thermometer invaluable to help me measure not only the temperature of the heating pad itself, but also how that temperature translated through the punnets to where the seeds were. (Temperature at the heating pad surface of 28⁰C resulting in a temperature of 22⁰C or less at the top of the punnet)
• Wiring hotspots – OK this not really my area of expertise (not being a sparkie and all) but I thought I would include it, especially for those wiring up their own low voltage house or shed energy systems. Electrical wiring, regardless of the voltage, can cause problems if it is not well carried out. Poor techniques, particularly when joining wires, can cause increased electrical resistance, and thus resulting in the production of heat at the join. If you check all of your wiring, especially joins, for unusual heat production, problems can be fixed before they start. I have heard of sparkies using IR thermometers to check for hotspots in the fuse box to identify problems, but as mentioned earlier this is not my area, so any concerns should be referred to someone qualified.
• If all else fails – the laser red dots are great fun for the cat to chase!
I have found the IR thermometer to be remarkably useful over the years, and it is well worth including one in your kit of tools to help you live the sustainable lifestyle.
