I recently changed my set-back in the downstairs part of the house to
58, down from 66 degrees at night. Could the warm up to 71 at 7 am. use more gas than keeping it 66 all night? I don't think it actually ever gets down to 58, and the furnace doesn't run at all during the night on this setting, and it used to run 3-4 times during the night to maintain 66 degrees.
If you DAGS on this, you'll find many extensive discussions. Distilled: unless you have a heat-pump (thus low recovery-rate, and use of resistive-electric heat strips), you will reduce energy use by setback. The physics and math are pretty simple.
Many regional utilities will provide local rule-of-thumb for pct- savings for a given setback amount.
The heat loss through the walls/windows/doors/roof of your house is proportional to the difference in temperature between the inside and the outside (and some wind effects too.) The greater that difference the faster the BTUs flow out.
If you keep it warmer at night more BTUs will flow out.
The less BTUs you lose overnight the fewer lost ones you'll have to replace the next day.
That answers the question. If you are correct I'm saving a degree &
1/2 per day. That in spite of bumping the daytime temperature up 2 degrees. I had it a 66 - 69, now at 58 - 71. I also bumped the setback time up 1/2 hour. The higher daytime temp was the goal, 69 was just too cold, it isn't worth sacrificing your health. I realize the temperature displayed by a thermostat is subjective, but this is a pretty good one, (Carrier Humidistat). The main thing is how you feel about it, and even with appropriate winter attire, 69 felt cold, unless you just came in from outside doing chores.
You haven't quite got it. Regardless of thermostat settings, you need to measure the average actual temps in the house before and after you changed the settings. Just because you set the thermostat at 58 - 71 doesn't mean your house is actually cooler on average. The house responds gradually in both directions, and each direction may be a different curve than the other.
Precisely, yes. It also depends on the average outside temperatures and so on as well. But, the time-weighted average thermostat settings will be a reasonable first approximation given other conditions the same.
Best answer is he seems to be more comfortable at the present setting and an observation of actual useage over a period of time will determine if there's a discernible reduction in useage. I'd venture it will be difficult to measure except over a longer time period at the mentioned settings unless the setback becomes much more extended relative to the previous.
What everyone else said, plus furnaces are more efficient the longer they run; so you actually save by letting the furnace run a long time to bring the temperature in the morning simply because of the long run.
A customer and 2 other neighbours have the exact same home and floor plan etc. All 3 homes are new with high effecient gas furnaces.
The customer and the two neighbours have relatively the same heating bill for January. About 108.00 Canadian
The customer's neighbours are home all day all the time and apparently keep the heat flowing as one would expect them.
The customer however works 8 hrs a day Mon-Friday. When the customer leaves for work, the heat is turned right down to it's lowest setting. What factors would cause the customer to have a similar gas bill.
Some contributing factors that I have dealt with.. small amount of air infiltration and a disconnected floor vent. The floor vent was in a well insulated space, so I don't think that would have contributed much.
What works for us is to have the heat go to 70 first thing in the morning, then after two hours it drops to 68. That way, you feel warm at first, but then as you become more active doing things, the 68 feels OK the rest of the day.
There can be many factors. Here's just one: The people who are home all day may keep a lot of lights and appliances on that contribute heat that will not be reflected in their heating bill.
This is said only partly in jest but any post-menapausal woman will suggest that body heat may contribute to a lower heating bill. Our thermostat is now 4° (68°) lower than a few years ago.
By the way, I'm south of Fort Worth. The high yesterday was 34, low last night was 23. My heat pump has operated 1 hr 41 minutes of the last 24 hours.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.