How does the Mercury in a thermostat work?
How does a mercury thermostat work? Mercury thermostats contain bimetal coils that contract and expand with room temperature. When the coil contracts or expands, it activates the mercury switch, which opens or closes a circuit to make the furnace, heat pump, or air conditioner turn on or off.
Do you have a mercury thermostat?
There are a few easy ways to quickly determine whether your home’s thermostat contains mercury. The first is simply to look at it. Mercury thermostats are manual, usually rectangular or circular in shape, and do not use digital displays. So, if your thermostat has a digital screen and curved edges, it probably isn’t a mercury thermostat.
Why use mercury in thermometers?
- Mercury is a good conductor of heat. ...
- Mercury is available in pure form.
- Mercury is opaque and bright; so movement of mercury inside the capillary tube is easily visible.
- Mercury does not stick to the glass surface. ...
- Expansion of mercury is uniform along the whole range of temperature. ...
How to wire your thermostat?
How to wire and secure your new programmable thermostat. Step 1: Wrap each wire underneath the appropriate screw, according to your notes or labels. Step 2: Use a screwdriver to tighten each screw around each wire. Step 3: Before securing the thermostat unit to the mounted base, be sure new batteries are put in and the reset button is pushed to ...
How do you know if thermostat has mercury?
To determine if your thermostat contains a mercury switch, remove the front cover. Once the cover is removed you should be able to locate one or more glass ampoules (switches) that contain a silver liquid (mercury).
When did they stop putting mercury in thermostats?
manufacturers in the U.S. – General Electric, Honeywell, and White-Rodgers. These companies reported that they phased-out the manufacture and sale of mercury-added thermostats in October 2009. Since 2001, many states have passed legislation restricting the sale of mercury-added thermostats.
Do thermostats use mercury?
Mercury Components in Thermostats Mercury thermostats use mercury switches to sense and control room temperature through communication with heating, ventilating, and air conditioning (HVAC) equipment.
Can the mercury in a thermostat hurt you?
In some homes, especially older ones, the electromagnetic thermostat that you depend on to consistently control your heating or cooling needs often contains mercury – a potent neurotoxin. Exposure can cause significant health problems, including damage to the central nervous system.
Where can you find mercury in your house?
Mercury Containing Products Commonly Found in HomesThermometers.Thermostats.Button Cell Batteries.Fluorescent light bulbs (tubes and CFLs)Mercury switches (in automobiles and appliances)Barometers.Blood pressure gauges.Mercury-Added Novelties.More items...
Do Honeywell thermostats have mercury?
Mercury is typically found in older mechanical thermostats like the Honeywell Round T87 and rectangular T8090. NOTE: Do not place your old thermostat in the trash if it contains mercury in a sealed tube.
When did they start using mercury in thermostats?
While Willis Carrier invented air conditioning as we know it in 1902, the first recorded use of a thermostat was a mercury thermostat invented by Cornelis Drebbel for use in a chicken incubator in Holland around the year 1620.
Should I replace my old mercury thermostat?
The Use of Mercury in Thermostats The circuit controls the on/off operation of an air conditioner, furnace, boiler or heat pump. Replacing outdated thermostats is a safety essential; disposal of mercury-filled thermostats should be left to professionals.
How much mercury is toxic?
Blood mercury levels above 100 ng/mL have been reported to be associated with clear signs of mercury poisoning in some individuals (e.g., poor muscle coordination, tingling and numbness in fingers and toes).
What mercury poisoning feels like?
Symptoms of mercury poisoning depend on the form of the mercury that was the source of the exposure. Early symptoms of mercury poisoning can include a metallic taste in the mouth and numbness and tingling in the hands, feet and face.
What do you do if you break a mercury thermometer?
Sprinkle sulfur powder over the contaminated area and rub it gently all over the surface and into the cracks with a paper towel. Sulfur powder binds with mercury. Use a paper towel dampened with water followed by wiping with another damp paper towel to clean up the sulfur and mercury.
What happens if you inhale mercury?
The inhalation of mercury vapour can produce harmful effects on the nervous, digestive and immune systems, lungs and kidneys, and may be fatal. The inorganic salts of mercury are corrosive to the skin, eyes and gastrointestinal tract, and may induce kidney toxicity if ingested.
Are mercury thermostats illegal?
In response to growing concerns over environmental health, the California legislature banned mercury-added thermostats in 2006.
Can I replace a mercury thermostat with a digital?
0:2612:19Upgrade from Mercury to Digital Thermostat - YouTubeYouTubeStart of suggested clipEnd of suggested clipThey're safer for the planet. They have less moving parts they're safer for your home because youMoreThey're safer for the planet. They have less moving parts they're safer for your home because you don't have the mercury.
Are old mercury thermostats accurate?
Myth:Mercury-bulb thermostats should be replaced because they are inaccurate. Fact:Mercury bulb thermostats are among the most accurate for temperature control within the HVAC industry. Cheap electronic thermostats provide inferior temperature control.
Where are mercury thermometers banned?
At least 13 states – California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon, and Washington – have passed such laws.
How accurate is mercury thermostat?
The accuracy of a mercury thermostat depends on whether the thermostat was properly calibrated, mounted in the right location, and leveled on the wall. With many influencing factors, especially when it comes to imprecise calibration, traditional thermostats can fail in providing a high accuracy temperature reading.
How does mercury work in thermometers?
Traditional thermometers use mercury to read and control the temperature in a space. The mercury is contained in a glass tube, and based on the fluctuations of temperature, it can reduce or increase its volume. Moving up and down on the reading scale, it will display the current temperature in a room. To get an accurate reading, the thermostat must be properly calibrated by using a thermal equilibrium technique.
How many wires does a thermostat have?
While most thermostats have an older two-wire system, some do have the modern four/five-wire system. Simply remove the thermostat and see how many wires are coming out of the wall. Wires come with color codes, so it might be useful to take a picture of the original wiring or sketch it on a piece of paper.
Is mercury a hazardous waste?
Considered to be hazardous waste, mercury thermostats have to be recycled properly. That’s why it is illegal to dispose of mercury thermostats along with regular garbage. Some states have completely banned the use of these thermostats in households and recommend switching to newer digital ones.
Can you replace mercury thermostats?
Replacing your existing mercury thermostat can be done as a DIY project as long as you have an understanding of how to deal with the wires. The first step is to remove the faceplate of the thermostat so you can get to the wires and determine the correct wiring system. However, if you are not comfortable with this, you can reach out to an HVAC technician that can easily get this done for you.
Is a digital thermostat safer than a mercury thermostat?
Modern digital thermostats are definitely safer than traditional mercury thermostats and they also have many more benefits. From energy-saving to remote access via a smartphone app – the new digital thermostats not only help you save money but also eliminate the potential dangers caused by hazardous substances like mercury. So even if your old thermostat is still working, give it a second thought and consider upgrading to a newer and smarter device, built to offer a hassle-free experience.
Is mercury safe to use in thermostats?
Having said that, unless you are directly exposed to a large quantity of mercury, having a mercury thermostat is safe.
What happens if a mercury thermometer breaks?
If a mercury thermometer breaks or leaks, it can release toxic vapors. Do not clean up spilled mercury with bare hands. Use protective gloves and contact a poison control center if any mercury is ingested or comes in contact with your skin. Writer Bio.
How to tell if a thermometer is safe?
See if your thermometer has a digital display. Such thermometers use a metal probe to sense temperature. Electronic components in the thermometer can take very accurate and fast temperature readings. They are also safe, since they can withstand temperature extremes without breaking.
What is a candy thermometer?
Many thermometers that use a dial, such as candy thermometers, use a metal spring that is sensitive to heat. As the metal heats and expands, the spring slowly unwinds, driving the dial or arrow attached to one end of a spring. A thermometer that registers temperature with a round dial uses this type of mechanism.
What is a thermometer used for?
They are often used for measuring body temperature, air temperature, or liquids used in cooking and candy-making.
Does a thermometer crack?
Take care in handling the thermometer so that it does not crack or break. Check if your thermometer is filled with a red-tinted fluid. This type of thermometer uses alcohol, not mercury, to sense temperature 2.
Is mercury a metal?
Mercury is a dangerous metal. If a mercury thermometer breaks or leaks, it can release toxic vapors. Do not clean up spilled mercury with bare hands. Use protective gloves and contact a poison control center if any mercury is ingested or comes in contact with your skin.
Is mercury in a thermometer safe?
While accurate, the mercury inside the thermometer is very dangerous if it comes in contact with skin 2. Take care in handling the thermometer so that it does not crack or break. Check if your thermometer is filled ...
