I don't know anything about DC motors in the context of a furnace, certainly I have never seen one but that doesn't mean they don't exist.
I have rarely had my furnace motor off in the 15 or 16 years since the furnace was installed, I never set it to auto and the reason is just as your man said, I prefer the more even temperature. My system is pretty noisy too and I prefer to accommodate the noise rather than have it intermittently come and go. In the summer I like the thought of constant air flow over the filter presumably keeping a little more of the dust down. Finally, in my case I have the house pretty well air tight so therefore constantly run an air exchanger which includes a heat recovery unit. The fresh air is dumped into the cold air return of the furnace where it is mixed and distributed through all rooms in the house. Doubtless the constant motor running does add some electric cost, it is a fan and a bit bigger than your average window fan but compared with most of the electrical equipment running around here it can't draw all that much. I am guessing three hundred Watts which is about 8 kilowatts per day in Ontario about forty cents a day. In auto mode it might save half of that or about 6 bucks a month. When I smoked I did that in a day. I don't know if the fan even does 300 Watts, someone on here will probably know. Clearly, running the fan full time does cost something, improved comfort might just be worth the cost. If the fan is AC or DC, well that doesn't really matter. You are correct that the electricity is the same source, converting to DC will have some losses in efficiency but I rather think that he is referring to the fact that as the armature of the motor turns it uses both halves of the alternating current wave form. I see that some other equipment refers to DC, some hand held circular saws for example. I have to think this is what they are referring to but I don't know that for certain. Hope this helps you decide what you want to do. Dale Leavens, Cochrane Ontario Canada [EMAIL PROTECTED] Skype DaleLeavens Come and meet Aurora, Nakita and Nanook at our polar bear habitat. ----- Original Message ----- From: Victor Gouveia To: Blind Handyman Listserv Sent: Sunday, June 03, 2007 1:04 PM Subject: [BlindHandyMan] Heating and Air Conditioning Question Hi All, I have a program in my city that provides for once per year cleaning of my air conditioning and furnace. This happened the other day, and I was told something very strange, and something I'd like to confirm with my fellow list members. While checking out the furnace, I blurted out a problem I had with my house, and asked for any opinions on the matter. I told him that I found my house was very cool in the basement, and very warm upstairs on the top floors, something I've been all too familiar with owning my own home for over two decades. He told me that I should run the fan in the on position, as opposed to the auto position. I told him that I couldn't afford that, as my electricity prices were too high as it was, and that would probably just run it way higher than I could afford. That's when he told me something I didn't know about. He told me that the fan motor was a DC unit, and that even if I ran it twenty-four hours per day, and seven days per week, it would only add pennies to my electricity bill every month. I found this strange, as I know that AC stands for Alternating Current, and DC stands for Direct Current, and essentially, it's the same thing, as both derive power from the same source. It would also mean that the amount of electricity would be the same, whether the fan was an AC fan or a DC fan. Could someone tell me if this is correct? Does it not derive power from the same source, thereby using the same electricity as an AC unit? Does a DC unit cost less to run, as opposed to an AC unit? I'm also worried about possibly burning out the fan motor, as it is continuously running all the time, and while I know that furnace motors are designed to withstand the heat, wouldn't it stand to reason that running it for long periods of time would cause it to run down faster, thereby resulting in more service calls, and more money for the contractor? Any thoughts on this matter would greatly be appreciated. Victor [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] To listen to the show archives go to link http://acbradio.org/handyman.html 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 The Pod Cast address for the Cooking In The Dark Show is. http://www.gcast.com/u/cookingindark/main.xml Visit The Blind Handy Man Files Page To Review Contributions From Various List Members At The Following address: http://www.jaws-users.com/handyman/ Visit the archives page at the following address http://www.mail-archive.com/[email protected]/ For a complete list of email commands pertaining to the Blind Handy Man list just send a blank message to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/blindhandyman/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/blindhandyman/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
