Is it more coat effective to let the temperature drop to the low 60s and have it kick back up to 70 30 minutes before we wake up then drop back off to the low 60s during the day and kick back up dieting the evening then drop down at bedtime
Or
Would it be cheaper to keep it a more consistent high 60s?
Most cost effective way to run heat
Re: Most cost effective way to run heat
I had this discussion with the installer of our new heating system when we bought our house. We have an oil boiler with hot water baseboards and indirect domestic hot water.
We discussed the range of 'turn down' that was the most effective for saving the boiler from running all the time and/or having to 'make up' too much heat loss.
His advice was to only turn down the temp 2-3 degrees at night. When I asked the reasoning for what I thought was such a small difference he explained that the lower inside temps would keep the boiler from running as much due to the time it would take for the inside temp to drop and then call for the boiler and, albeit small temp difference between outside and inside air would call for less heat as well.
The biggest reason was that when you lower the temp inside too much, you then lower the temp of the walls, furniture, etc and when the temp desired goes back up in the morning, the boiler has to fight to heat all of these cold masses that retain the lower temp until they reside in warmer temps for a longer time. This calls for more heat to overcome the 'cooler effect' like ice cubes in a cooler.
All that said, we have three heating zones in our house, one for the main first floor area, one upstairs (bedrooms and a bath) and one in the mudroom/laundry addition that was an attached garage at one point in the 40's.
The mudroom has a pine floor with no sub floor, it is over a 12" crawl space that has the broken concrete floor of the old garage in it and no insulation on the foundation. We keep that room that thermostat at 64 during the day and 62 at night. We are lucky since the original exterior door from the kitchen is still in place and we can close off the mudroom in winter.
The main house we keep at 67 during the day and lower to 65 at night. We have determined over the years that 67, with the 2x4 construction and lots of windows, thus a pretty decent heat loss/cold infiltration ratio is about as low as we can go and be comfortable.
Upstairs we leave the heat at 64 all the time. Heat rises and we shut the door to unused rooms and let the heat go into our bedroom and the bath. The thermostat is in our bedroom. This generally keeps the temps above 64 and the heat upstairs only comes on when the outside temps are in the 20's, keeping it above 64.
All three zones have programmable thermostats and all are on the same time schedule. Most programmable thermostats can be set to have a custom time schedule (when the heat goes up/down) that meets your needs. We do not lower the temps during the day as some do since my wife and I both have varied work schedules and do not have the same time/days off, etc. Some have 7 day programming meaning all days can have their own schedule, weekday/weekend programming, or one program for all 7 days.
We go to bed late and rise early so the temp drop for night comes at 10pm and kicks back up at 6am. The temps in the house are generally the same when we go to bed at 11 or 11:30 unless it's really cold outside. Even though 2 degrees sounds small, I must admit that the heat coming on at 6am does make the house feel 'toasty' in the morning since the heat has just come on and warmed the place.
Since moving in and finding areas to improve (new boiler without heat coil for domestic water, replacing the old rotary analog thermostats with digital programmable, insulation in the attic, deadlights on windows and I have rebuilt several outside walls and insulated well) we have cut the fuel usage in half from what the previous owners used when we bought the place.
Bottom line is, we have found that a 2 degree difference in night/day programming has worked for us, both in comfort and fuel savings.
We discussed the range of 'turn down' that was the most effective for saving the boiler from running all the time and/or having to 'make up' too much heat loss.
His advice was to only turn down the temp 2-3 degrees at night. When I asked the reasoning for what I thought was such a small difference he explained that the lower inside temps would keep the boiler from running as much due to the time it would take for the inside temp to drop and then call for the boiler and, albeit small temp difference between outside and inside air would call for less heat as well.
The biggest reason was that when you lower the temp inside too much, you then lower the temp of the walls, furniture, etc and when the temp desired goes back up in the morning, the boiler has to fight to heat all of these cold masses that retain the lower temp until they reside in warmer temps for a longer time. This calls for more heat to overcome the 'cooler effect' like ice cubes in a cooler.
All that said, we have three heating zones in our house, one for the main first floor area, one upstairs (bedrooms and a bath) and one in the mudroom/laundry addition that was an attached garage at one point in the 40's.
The mudroom has a pine floor with no sub floor, it is over a 12" crawl space that has the broken concrete floor of the old garage in it and no insulation on the foundation. We keep that room that thermostat at 64 during the day and 62 at night. We are lucky since the original exterior door from the kitchen is still in place and we can close off the mudroom in winter.
The main house we keep at 67 during the day and lower to 65 at night. We have determined over the years that 67, with the 2x4 construction and lots of windows, thus a pretty decent heat loss/cold infiltration ratio is about as low as we can go and be comfortable.
Upstairs we leave the heat at 64 all the time. Heat rises and we shut the door to unused rooms and let the heat go into our bedroom and the bath. The thermostat is in our bedroom. This generally keeps the temps above 64 and the heat upstairs only comes on when the outside temps are in the 20's, keeping it above 64.
All three zones have programmable thermostats and all are on the same time schedule. Most programmable thermostats can be set to have a custom time schedule (when the heat goes up/down) that meets your needs. We do not lower the temps during the day as some do since my wife and I both have varied work schedules and do not have the same time/days off, etc. Some have 7 day programming meaning all days can have their own schedule, weekday/weekend programming, or one program for all 7 days.
We go to bed late and rise early so the temp drop for night comes at 10pm and kicks back up at 6am. The temps in the house are generally the same when we go to bed at 11 or 11:30 unless it's really cold outside. Even though 2 degrees sounds small, I must admit that the heat coming on at 6am does make the house feel 'toasty' in the morning since the heat has just come on and warmed the place.
Since moving in and finding areas to improve (new boiler without heat coil for domestic water, replacing the old rotary analog thermostats with digital programmable, insulation in the attic, deadlights on windows and I have rebuilt several outside walls and insulated well) we have cut the fuel usage in half from what the previous owners used when we bought the place.
Bottom line is, we have found that a 2 degree difference in night/day programming has worked for us, both in comfort and fuel savings.
Etta says "WOOF"
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Nicholas
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Re: Most cost effective way to run heat
It is 4:30 am, as I am an early riser, and temps here are just now at 39. I had the thermostat on the heat strip Rheem set at 72, these floors are cold, crawlspace, no insulation below.
This Rheem has the circuit board controls that start the outside unit first, then the airhandler, and shuts down in reverse order, which it did most of the night.
So as I am reading this post, I noticed that the outside unit shut off, but before the handler shut down, the outside unit came back on. Seems to be running steady now. I am going to lower it to 70 see what happens. I think this house holds the cool better than it holds the heat.
Having said that I believe in the maintain temperature school of thought for saving power, I never use the program.
I am still toying with the idea of putting an antique style wood burning stove back where one used to be. If nothing else, just for the looks because it wouldn't be used often.
Usually I shut off the heat as soon as the sun comes up, the house will stay in the high 60's to 70's.
This Rheem has the circuit board controls that start the outside unit first, then the airhandler, and shuts down in reverse order, which it did most of the night.
So as I am reading this post, I noticed that the outside unit shut off, but before the handler shut down, the outside unit came back on. Seems to be running steady now. I am going to lower it to 70 see what happens. I think this house holds the cool better than it holds the heat.
Having said that I believe in the maintain temperature school of thought for saving power, I never use the program.
I am still toying with the idea of putting an antique style wood burning stove back where one used to be. If nothing else, just for the looks because it wouldn't be used often.
Usually I shut off the heat as soon as the sun comes up, the house will stay in the high 60's to 70's.
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Ober51
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Re: Most cost effective way to run heat
My gravity-fed hot water system would take forever to adjust to temperatures. We are going to try to simply keep them at 65-68. That being said, we still do not have heat in our house.... The plumber/heating guy is trying to get it all done tomorrow. We are pushing our luck here in NJ without heat.
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phil
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Re: Most cost effective way to run heat
I just have gas forced air. one thing I did was install a programmable timer. I set it to dip just a little at night and to warm up around meal times. If I'm at work it drops but it is easy to override the heat for the present period so I just tell my girlfriend if she's cold turn it up and as the program goes to the next time block it goes back to the scheduled program.
I'm not sure about the load of preheating or how one could even calculate that but I like it to come on when I shower and get ready in the morning and I like that it can warm the place up before I get home. there is something nice about having the heat running when you are doing things like getting ready in the morning and the timer schedules that to happen on a schedule so you can use that to your advantage as well.
I burn wood when it's convenient, that helps. My bathroom never had a fan and I do see tiny black specks on the ceiling. I replaced the bulbs and try to leave them on more as it sends a little heat up to the ceiling but it is starting to concern me a little. If I burn the fire maybe it doesn't get as much heat to some areas because the fire warms the thermostat
I'm not sure about the load of preheating or how one could even calculate that but I like it to come on when I shower and get ready in the morning and I like that it can warm the place up before I get home. there is something nice about having the heat running when you are doing things like getting ready in the morning and the timer schedules that to happen on a schedule so you can use that to your advantage as well.
I burn wood when it's convenient, that helps. My bathroom never had a fan and I do see tiny black specks on the ceiling. I replaced the bulbs and try to leave them on more as it sends a little heat up to the ceiling but it is starting to concern me a little. If I burn the fire maybe it doesn't get as much heat to some areas because the fire warms the thermostat
Re: Most cost effective way to run heat
THe correct term for this is "setback", just in case anyone needs to learn more. I've found out that most heating engineers agree that it doesn't make sense precisely for the reasons outlined above - warming up all those walls, furniture, air probably uses as much heat as it was saved by not running the boiler at night. Yet you suffer from decreased comfort.
In my house I don't actually have a thermostat at all. The boiler is set to run continuously and modulate the heat output depending on the outdoor temperature. If the temperature outside is bellow 50 degrees the boiler usually runs continuously for hours, adding just enough heat to replace what's lost.
All radiators have Thermostatic valves which allow limit control in individual rooms. Those valves also don't just open/close, but regulate the flow proportionate to the rooms demand.
In bedrooms I have programmable TRVs(had to import from Europe) which allow me to lower the temperature at night because we like to sleep in a fairly cold(sub 60) room. Then the heat climbs back up to 70 by the time we wake up around 10.
It's kind of unfortunate, but most heating systems(especially hydronic) installed in US are literally in the Stone Age compared to how it's done in Europe.
In my house I don't actually have a thermostat at all. The boiler is set to run continuously and modulate the heat output depending on the outdoor temperature. If the temperature outside is bellow 50 degrees the boiler usually runs continuously for hours, adding just enough heat to replace what's lost.
All radiators have Thermostatic valves which allow limit control in individual rooms. Those valves also don't just open/close, but regulate the flow proportionate to the rooms demand.
In bedrooms I have programmable TRVs(had to import from Europe) which allow me to lower the temperature at night because we like to sleep in a fairly cold(sub 60) room. Then the heat climbs back up to 70 by the time we wake up around 10.
It's kind of unfortunate, but most heating systems(especially hydronic) installed in US are literally in the Stone Age compared to how it's done in Europe.
Re: Most cost effective way to run heat
Interesting that you should mention heating based upon the outside temperature...one of the items we installed with the new boiler system that I did not mention above is a Tekmar controller. It essentially 'tells' the boiler what heat output to create depending upon the outside temps. i.e.: if it's 50F outside, it tells the boiler only to heat to 120F for circulated water, when it's 20F outside, it tells the boiler to heat to full heat, etc. This allows better efficiency and burns less fuel yet heats as needed.
Regarding your boiler running continuously....do you burn a lot of fuel? If my boiler ran continuously, I would need to own an oil company!
Regarding your boiler running continuously....do you burn a lot of fuel? If my boiler ran continuously, I would need to own an oil company!
Etta says "WOOF"
Re: Most cost effective way to run heat
Ive been trying only setting it back to 67 at night and 70 for when we wake up, back down to 67 during the day, back up to 70 in the evening and back down to 67 at night.
We are suffocating at night it gets so hot. lol
Were not sweating, its more of a dry heat. I had to get up to get water last night and the rest of the house felt comfortable, but our bedroom stays exceptionally warm. We keep the door shut for 2 reasons, one being Im scared of seeing something pass the door in the middle of the night and two because its safer if there was ever a fire in the house.
We are suffocating at night it gets so hot. lol
Were not sweating, its more of a dry heat. I had to get up to get water last night and the rest of the house felt comfortable, but our bedroom stays exceptionally warm. We keep the door shut for 2 reasons, one being Im scared of seeing something pass the door in the middle of the night and two because its safer if there was ever a fire in the house.
Re: Most cost effective way to run heat
SkipW wrote:Regarding your boiler running continuously....do you burn a lot of fuel? If my boiler ran continuously, I would need to own an oil company!
No, I have modulating condensing gas boiler. Its 85k BTU but it can modulate it's firing rate down to about 1/5 of that, so 17. Thats only about the size of a boiler burner on a stove.
It's actually better for overall efficiency for the boiler to run continuously as the combustion doesn't get to the optimal stage for a minute or so after starting, so less often the boiler cycles on/off is better. Also better for the boiler too as no device likes turning on and off.
Unfortunately modulating oil boilers are only really available in EU, so only people with gas can take advantage of it
Re: Most cost effective way to run heat
hmm, i'm going to get in touch with my wonderful boiler guy and see what he says...
I keep the thermostat at 55 when i'm gone for at least 10 hours a day...I turn it up to 63 when I get and anything above that is too warm for me...I put it back down to 55 for 7-8 hours of sleep time at night...it takes about 20 minutes for the boiler to get the heat up to where it's not chilly...
when I stay with family or friends overnight, it is so hot that I close the bedroom door and open a window...otherwise I wake up with a banging headache...
...jade...cool as a cucumber.....
I keep the thermostat at 55 when i'm gone for at least 10 hours a day...I turn it up to 63 when I get and anything above that is too warm for me...I put it back down to 55 for 7-8 hours of sleep time at night...it takes about 20 minutes for the boiler to get the heat up to where it's not chilly...
when I stay with family or friends overnight, it is so hot that I close the bedroom door and open a window...otherwise I wake up with a banging headache...
...jade...cool as a cucumber.....