Gregor 4,846 #1 Posted November 18, 2021 Last week my wife came out to the garage and saw that I had the thermostat set at 74. That's warmer than I usually I have it, but I was cold that day. I normally have it at 70 or 71. She asked me if I turned it down at night, I told her no. Coincidentally, this very subject came up today on another forum. So this is what I did. I wired an analog clock to my natural gas hanging heater. The clock only runs when the furnace is running. I have the thermostat set at 71. I will let it run this way for 24 hours. I will check the clock tomorrow at 1 PM . Tomorrow night, I will turn the heat down to 45 for the evening, turn it back up to 71 when I come out to the garage. At 1 PM Friday, I'll check the clock for hours ran . We shall see. My garage is a bit unique. It has a concrete floor, yet has a full walk out basement. The way my land lies, I had to pour footings and walls to set my garage at the same level as my house. Yeah it cost a bit more for the pre-stressed concrete floor, but not as much as another 24 X 26 garage, which is what I have. My point in explaining this is, my floor is not insulated by dirt, or anything else. The bottom side is open to the basement, which is not heated at all, and yes it gets COLD ! I should probably also explain further. The clock is wired in parallel to the induction fan. The induction fan starts shortly before the burner is fired, and stops when the burner goes out. 7 Share this post Link to post Share on other sites
squonk 41,150 #2 Posted November 18, 2021 We used to use an old analog clock to keep track of chemical feed pumps in the boiler room. I still have it under the bench Share this post Link to post Share on other sites
953 nut 55,305 #3 Posted November 19, 2021 1 hour ago, Gregor said: pre-stressed concrete floor If yours is like the pre-stressed slabs I have worked with there are several voids filled with air in the slab that will give some reasonable amount of insulation compared to a sloid concrete slab. You will probably find that the heater will run less to make up temperature than if it maintained it all night. 2 Share this post Link to post Share on other sites
Gregor 4,846 #4 Posted November 19, 2021 (edited) 23 minutes ago, 953 nut said: If yours is like the pre-stressed slabs I have worked with there are several voids filled with air in the slab Yes they are basically hollow, with a webbing. End view of my concrete slabs There is a 4" slab poured on top of these. Edited November 19, 2021 by Gregor Share this post Link to post Share on other sites
953 nut 55,305 #5 Posted November 19, 2021 3 minutes ago, Gregor said: they are basically hollow, with a webbing R Value is about 2 as compared to 0.4 for a solid slab. It isn't much but better than nothing. The basement area probably helps cool your shop in the summer. Share this post Link to post Share on other sites
Gregor 4,846 #6 Posted November 19, 2021 6 minutes ago, 953 nut said: The basement area probably helps cool your shop in the summer. Not as much as the 24K BTU AC ! 1 3 Share this post Link to post Share on other sites
ebinmaine 67,596 #7 Posted November 19, 2021 I'll be interested to see your findings. I can tell you that here we installed a timer auto off/on electric thermostat back when we had oil heat. Paid $25 for it and got that back within 2 or 3 months. 2 Share this post Link to post Share on other sites
WHX?? 48,828 #8 Posted November 19, 2021 2 hours ago, Gregor said: I wired an analog clock to my natural gas hanging heater. Wow sounds like a PO cobblement I see when on service calls. Do yourself a favor and get the proper thermostat that will do things the right way! Sounds like with what you are doing you just need a standard programable thermostat? Now that eklectricy come to town I have WiFi stats on everything now and can check and adjust them dang near from anywhere. 'Course I put bacon on the table with them too and get them for a four letter word that starts with F. 1 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #9 Posted November 19, 2021 (edited) 5 hours ago, WHX?? said: get the proper thermostat I don't think he's using the clock as a thermostat, only tracking the run time of the burner to compare and decide if it pays to set it back or not. I did some extensive experimentation for a few years about a decade ago. I tracked the gallons of oil burned and degree days over long periods of time so as to get rid of the statistical 'noise'. I found that setting the thermostat back at night didn't save anywhere near what I was led to believe or hoped it would save. As I recall it was something less than 2% over the course of the winter. Keep in mind that this was correlated with heating degree days so a warmer or colder winter didn't mess with the results. My conclusion was that to heat everything back up again after an overnight setback period pretty much burnt up whatever was saved during the setback period. Setting back and LEAVING it set back would of course save more. But the Treasurer is cold-blooded and she likes to be warm and happy. And I like her to be warm and happy! So I set it at 70° and just leave it alone. Sometimes the Treasurer kicks it up to 71° and she gets no complaints from me. Happy wife / Happy life. Edited November 19, 2021 by Jeff-C175 3 Share this post Link to post Share on other sites
Maxwell-8 4,277 #10 Posted November 19, 2021 We also have thermostat, running it on 60°. Every morning when I will have to work in the garage, I will go out turn it on before breakfast. The garage/ barn is a concrete floor, made out of metal but insulated. At night it gets as cold as outside. We burn about 15 gallons of diesel a day heating up the place. so we tend to not turn on the heating unless it is below 40. 1 Share this post Link to post Share on other sites
Pullstart 62,906 #11 Posted November 19, 2021 If it’s a constant 40 degrees for example, dropping the t-stat for anything more than 8 hours closer to that 40 mark is a lower delta t. Lower delta-t, cheaper energy cost. That’s hard to argue. Most furnaces prefer not to short cycle. Long run times (and still maintaining comfort) is best. I’m all for a setback control style thermostat. I have one, but haven’t taken the time to mess with any programming however. We also have an old school bi-metal t-stat for the wood boiler. The water heaters are always the same temp as the boiler in heating months and the furnace only fires when I forget to fill the boiler 1 Share this post Link to post Share on other sites
squonk 41,150 #12 Posted November 19, 2021 (edited) All he's doing is keeping track of furnace run time. Not controlling it. I'm with Jeff. Unless you're gone for extended periods, set back does little for savings. You have to warm up not only the air but every object in the space is some sort of heat sink. And depending on what the space is made of, wood, concrete,steel all that has to be heated back up as well. Set it to where you like it and forget it. Wi fi stats are for people who can't put down their phone. I did all the bldg automation at the hospital. The brass wanted all these areas and boilers with their related pumps to be able to be controlled by their phones. We finally did an energy survey. 1 month their way and one month my way. Savings were almost non existent. Plus a lot less complaints and problems when you're not turning things on and off all the time. Edited November 19, 2021 by squonk 2 1 Share this post Link to post Share on other sites
Gregor 4,846 #13 Posted November 19, 2021 18 minutes ago, squonk said: Plus a lot less complaints and problems when you're not turning things on and off all the time. Share this post Link to post Share on other sites
squonk 41,150 #14 Posted November 19, 2021 My favorite was my boss like to play with the building settings from home. He had a thing for humidity. We had a big elevator lobby. Concrete floor with tile. Directly below it was a massive air intake plenum for all of the air handlers for that bldg. I was like 0° out side so imagine the windchill in that plenum. I walk into the lobby and the director of the cleaning staff is wiping the floor. I ask him what's up and he says the floor is wet and won't dry! I sit down in a lobby chair and can see the outline of the plenum on the tile. He had the humidity soo high it was condensing on the cold area where the plenum was. Another time I walked into the ER on a winter day. It was like a rain forest in there. Windows were all wet and it wasn't raining or snowing outside. Yup he had the humidity too high. Instead of letting the system programming take care of it he HAD to tweak it. Get it set and forget it! 1 1 Share this post Link to post Share on other sites
WHX?? 48,828 #15 Posted November 19, 2021 (edited) 1 hour ago, Pullstart said: If it’s a constant 40 degrees for example, dropping the t-stat for anything more than 8 hours closer to that 40 mark is a lower delta t. Lower delta-t, cheaper energy cost. That’s hard to argue. Most furnaces prefer not to short cycle. Long run times (and still maintaining comfort) is best. I’m all for a setback control style thermostat. I have one, but haven’t taken the time to mess with any programming however. We also have an old school bi-metal t-stat for the wood boiler. The water heaters are always the same temp as the boiler in heating months and the furnace only fires when I forget to fill the boiler You need a job dude?!?!? I'd hire you in a second! Pay is good but hours are long and buy you a nice truck to run around in and all the Milwaukee tools you care to have ..... 6 hours ago, Jeff-C175 said: setting the thermostat back at night didn't save anywhere near what I was led to believe This is true but many other factors come into play. Type of fuel, efficiency it is being burned at, type of structure, offset or how many degrees you are setting it back, offset time, insulation levels and most important infiltration levels. 100 yo farm house no... 1600 sq ft ranch built to todays codes ...Yes 14 minutes ago, squonk said: boss like to play with the building settings from home. 14 minutes ago, squonk said: Get it set and forget it! Edited November 19, 2021 by WHX?? 1 Share this post Link to post Share on other sites
Pullstart 62,906 #16 Posted November 19, 2021 17 minutes ago, WHX?? said: You need a job dude?!?!? I'd hire you in a second! Pay is good but hours are long and buy you a nice truck to run around in and all the Milwaukee tools you care to have ..... do you pay drive time? In dollars or meat sticks? Share this post Link to post Share on other sites
Pullstart 62,906 #17 Posted November 19, 2021 19 minutes ago, WHX?? said: insulation levels and most important infiltration levels my shack is a little drafty. Not much thermal insulation here. 3 Share this post Link to post Share on other sites
squonk 41,150 #18 Posted November 19, 2021 21 minutes ago, WHX?? said: hours are long a When the boss is playin with tractors all the time no wonder the hours are long! Somebody has to work! 2 Share this post Link to post Share on other sites
953 nut 55,305 #19 Posted November 19, 2021 When I lived in central NY I had two thermostats and a seven day time clock connected to the furnace. Weekdays the time clock would switch at 8:00 am to the thermostat in the basement which was set to fifty degrees to keep the pipes from freezing. At 3:30 pm it would switch to the living area thermostat set at seventy degrees so it would be nice and warm when I got off work. Weekends it would stay on the living room thermostat. When I moved to Florida a friend and his bride rented the house for a year or so while they were building their new house, both of them worked so the whole thing worked well for them too. Once they were in their new house I sold the house to a couple with young children and a stay at home mom. When the winter weather started the lady of the house would complain to her husband that the house was cold all day, of course it was nice and warm when he got home so he figured she was crazy. One day the lady of the house saw my mother while shopping and they struck up a conversation. My mother knew about the time clock, problem solved, she wasn't crazy after all. 2 4 Share this post Link to post Share on other sites
WHX?? 48,828 #20 Posted November 19, 2021 Your story reminds me of this one Richard! 1 5 Share this post Link to post Share on other sites
JoeM 7,874 #21 Posted November 19, 2021 1 hour ago, Pullstart said: In dollars or meat negotiate in bacon-coin! 1 1 Share this post Link to post Share on other sites
squonk 41,150 #22 Posted November 19, 2021 Before I worked at the hospital the guy who took care of all the automation was an Ex-Kodak engineer. He was wired for sound. I saw him more than once running down the hallways going from one place to another. After I started working there I heard stories from the guys how the automation guy would go around the entire campus constantly tweaking things and the lead mechanic about 10 minutes behind him switching everything to "hand " so things would actually run. 3 Share this post Link to post Share on other sites
Jeff-C175 7,202 #23 Posted November 19, 2021 6 minutes ago, squonk said: Ex-Kodak engineer Mighta been my Daddy! Share this post Link to post Share on other sites
ebinmaine 67,596 #24 Posted November 19, 2021 1 hour ago, 953 nut said: she wasn't crazy after all. Well....... At least not for that particular reason....... 1 Share this post Link to post Share on other sites
squonk 41,150 #25 Posted November 19, 2021 3 hours ago, Jeff-C175 said: Mighta been my Daddy! Did he have a white afro and beard and weigh 100 lbs? Share this post Link to post Share on other sites