Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site hou4b.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxj!houxm!hogpc!houti!ariel!hou4b!dwl From: dwl@hou4b.UUCP Newsgroups: net.consumers,net.misc Subject: Re: Furnace anticipator setting Message-ID: <1187@hou4b.UUCP> Date: Thu, 18-Oct-84 17:08:07 EDT Article-I.D.: hou4b.1187 Posted: Thu Oct 18 17:08:07 1984 Date-Received: Sun, 21-Oct-84 09:47:21 EDT References: <152@ssc-vax.UUCP> Organization: AT&T Information Systems Laboratories, Holmdel, NJ Lines: 27 Maximum efficiency (minimum fuel for a given indoor average temperature) is reached with long on-time duty cycles. This is because the furnace gets the opportunity to run at maximum temperature, where maximum heat transfer occurs. It's internal limit switch should be set to keep it from getting hotter than that temperature. As the original news item pointed out, rapid cycling produces the most uniform temperature (minimum deviation from average) which is probably the most comfortable. It "correct" anticipator setting will therefore be a compromise between comfort and efficiency. In general, the thermostat manufacturer's recommended compromise setting can be obtained by setting the anticipator control to the number (in milliamps, usually) corresponding to the current rating of your gas control valve. Starting with this setting, vary it a little at a time to find comfort, if the original setting is not comfortable. The anticipator is there because your furnace keeps producing heat after the thermostat opens. The anticipator causes the thermostat to open a little before the temperature increases to the set point, in "anticipation" of the continued furnace output. If you have a very old or a very large furnace (lots of iron) you will probably need to set the anticipator to a lower number of amperes, so that it will anticipate more than average thermal inertia. -Dave Levenson AT&T-ISL Holmdel