On my old mercury thermostat the heat anticipator was not adjustable. On the new one non mercury the heat anticipator is adjustable and set at .2 whatever that means. Talking to the manufacturer of the vip1000 the heat anticipator is not adjustable. ----- Original Message ----- From: "Dale Leavens" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, October 23, 2008 9:14 AM Subject: Re: [BlindHandyMan] HowStuffWorks "Thermostat Controls"
Ah, That is a mercury switch. These are already delayed because the mercury in the vial has to expand enough to carry the center balance point past a trip point to open or close the circuit. Interesting though I didn't know exactly how that bit of the device was intended to work. These new electronic thermostats have thermister diodes I believe. They may well have some anticipatory circuitry however in the plenum of a furnace there are high and low temperature sensors which are intended to provide both safety and level out those highs and lows. The fire can therefore go on and off several times while raising the house temperature and before satisfying the thermostat without blasting heat above a safe or comfortable temperature. These used to be a tube several inches long projecting into the plenum but the technology has changed, I don't actually know where these sensors are in my present furnace. ----- Original Message ----- From: Lenny McHugh To: handyman-blind Sent: Thursday, October 23, 2008 8:32 AM Subject: [BlindHandyMan] HowStuffWorks "Thermostat Controls" Heat Anticipator Thermostats have a neat device called a heat anticipator. The heat anticipator shuts off the heater before the air inside the thermostat actually reaches the set temperature. Often, some parts of the house will reach the set temperature before the part of the house containing the thermostat does. The anticipator shuts the heater off a little early to give the heat time to reach the thermostat. The anticipator is a ring of resistive wire on the dial. The loop of wire above is actually a resistor. When the heater is running, the current that controls the heater travels from the mercury switch, through the yellow wire to the resistive loop. It travels around the loop until it gets to the wiper, and from there it travels through the hub of the anticipator ring and down to the circuit board on the bottom layer of the thermostat. The farther the wiper is positioned (moving clockwise) from the yellow wire, the more of the resistive wire the current has to pass through. Like any resistor, this one generates heat when current passes through it. The farther around the loop the wiper is placed, the more heat is generated by the resistor. This heat warms the thermometer coil, causing it to unwind and tip the mercury switch to the right so that the heater shuts off. http://home.howstuffworks.com/home-thermostat2.htm [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ Send any questions regarding list management to: [EMAIL PROTECTED] To listen to the show archives go to link http://www.acbradio.org/pweb/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=33&MMN_position=47:29 Or ftp://ftp.acbradio.org/acbradio-archives/handyman/ The Pod Cast address for the Blind Handy Man Show is. http://www.acbradio.org/news/xml/podcast.php?pgm=saturday Visit The Blind Handy Man Files Page To Review Contributions From Various List Members At The Following address: http://www.jaws-users.com/JAWS/handyman/ Visit the archives page at the following address http://www.mail-archive.com/[email protected]/ If you would like to join the JAWS Users List, then visit the following address for more information: http://www.jaws-users.com/ For a complete list of email commands pertaining to the Blind Handy Man list just send a blank message to: [EMAIL PROTECTED] Groups Links __________ NOD32 3548 (20081023) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com
