Thermostats are an absolutely necessary part of home heating. They are the control centers, the brains of the whole operation. Without them, you would have to manually turn your heater on and off every time you wanted to adjust the temperature. That’s not to say that all thermostats are created equal, however. Let’s take a look at how older thermostats are constructed, and how they contribute to inefficiency.
Thermostat Construction
All thermostats have a couple of basic parts shared between them. There’s always a sensor and a control circuit, along with a dial or other kind user interface. Older thermostats were pretty crudely constructed. Instead of the more precise electronic sensors thermostats have today, they used heat sensitive coils or ampules filled with mercury. A lot of these older thermostats have now been replaced, but there are still a few homes where they are used. It is this older construction that contributes to heating system inefficiency.
Old Thermostat Issues
The main problem with older thermostats is that of accuracy. Older thermostats were largely mechanical in nature, which meant they were more prone to failure when one of those mechanical parts experienced issues. The heat sensitive coils used to monitor temperature acted as circuit switches. When the temperature got warm enough, the coil would expand until it touched a lead at either end of the chamber and closed the circuit, starting the air conditioner. When the temperature cooled enough, the coil would contract, breaking the circuit to shut down the air conditioner. The problem is that these coils had a “dead zone” where it’s not hot enough for them to expand, but still hotter than what the thermostat is set for.
Mercury ampules had similar problems. As the temperature fluctuated in the home, it would cause the mercury in the ampule to fluctuate as well. This would tip the ampule one way or another to start the heater or the air conditioner. The problem is that this ampule could actually get stuck inside the thermostat, rendering the entire thing unable to operate.
Older thermostats are inefficient because of the archaic way in which they operate.
If you want your heating or air conditioning system to work much better than it normally does, contact G&S Heating, Cooling & Electrical, Inc.
