Tuesday, July 5, 2011
Most homes have a thermostat that controls the heating and air conditioning. Understanding that your thermostat is a valuable item in your home is paramount. Seriously, it is the key to how much you pay for your energy.
Here are some basic features of a digital thermostat.
Mercury switch - a glass vial with a small amount of actual mercury inside. Mercury is a liquid metal — it conducts electricity and flows like water. Inside the glass vial are three wires. One wire goes all the way across the bottom of the vial, so the mercury is always in contact with it. One wire ends on the left side of the vial, so when the vial tilts to the left, the mercury contacts it — making contact between this wire and the one on the bottom of the vial. The third wire ends on the right side of the vial, so when the vial tilts to the right, the mercury makes contact between this wire and the bottom wire.
Thermomoters is a component that exists , usually display on the cover. The other is on the top layer of the thermostat.
These thermostats are coiled bimetallic strips. Bimetallic strip is a piece of metal made by laminating 2 pieces of metal together. The center of the coil is connected to the temperature lever, and the mercury switch is mounted to the end of the coil. So when the coil winds or unwinds, this tips the mercury switch one way or the other.
Non Digital Thermostat
In the older homes chances are the thermostats are not digital. This type of thermostats have 2 switches, these switches move metal balls that make contact between different traces on the circuit card inside the thermostats. One switch controls the heat/cool, the other controls the circulation fan.
Whew, thats the basics of the nomenclature and basic functions inside a thermostat. Yes, there are other types that is way beyond the focus of this article.
The purpose of this post is to let our reader know the basic functions of a thermostats. If you need one replace, you can have a certified hvac technician like Cool Ace Air do this. Again the point of this post is to give you some knowledge about thermostats when you’re talking to a tech.