Thermostat setting - one temp and leave it or variable?

Reply

  #1  
Old 04-29-05, 01:29 AM
Member
Thread Starter
Join Date: Apr 2003
Posts: 55
Thermostat setting - one temp and leave it or variable?

Which way saves fuel consumption?
1. Setting the zone/house temperature to 68 F and leaving it or
2. Vary the temperature for time of day, e.g. turn it down to 56 F for sleeping and when away and turn up to 68 F when occupants are up and around the living area?

The explanation I hear for setting to a single temperature and not touching it is that when one lets the house cool down and then it's time to heat up, one energy is used to reheat all the furniture, walls, etc.

What is the right answer?
 
Sponsored Links
  #2  
Old 04-29-05, 01:55 AM
pgtek's Avatar
Member
Join Date: Oct 2004
Location: north Carolina
Posts: 1,391
hi
set it one temp and leave.
68 would be ok
if you place at 58 and back to 68 during the day, will cost you more for it has to run a long time to heat up

pg
 
  #3  
Old 04-29-05, 06:01 PM
Member
Join Date: Oct 2004
Location: in
Posts: 126
Thats false. Thats why they make programmable thermostats.
Every second the furnace or AC is not running its saving you money and saving fuel.
The argument about the couch and chairs needing to be "reheated" is a mute point. Your not going to be gone long enough for the furniture to lose enough heat. Bottom line is change the temp according to your living patterns...buy a programmable thermostat.
 
  #4  
Old 04-30-05, 12:26 AM
Member
Thread Starter
Join Date: Apr 2003
Posts: 55
Temperature management for heating efficiency

I am one who has programmable thermostats. My father is the one who keeps his little bungalow at a constant 68 F. I would like to prove to him that he won't save money by keeping the temperature constant. I'd like to be able to show him he could save money.

May be the answer is to get him the programmable thermostat, install it, set the program and run it for a season.

Just wasn't sure if anyone had specific data/examples particularly for a Northeastern US climate.
 
  #5  
Old 04-30-05, 11:42 AM
Member
Join Date: Nov 2001
Location: USA
Posts: 1,873
There are a lot of factors when considering if turning down a thermostat during the winter is cost effective. In general if the house is insulated it should be cost effective. If not, it is not cost effective. Basically insulation retards heat loss, it does it by retaining heat. This characteristic allows you to turn down the thermostat a portion of the day without having to reheat the structure and all furnishings in it again. Without insulation, the heat loss would be so great that you would have to heat the structure and all the furnishings within.

Heat loss is then the determining factor concerning the cost effectiveness of turning down thermostats. Factors like air leakage, infiltration and the by-pass phenomena affect heat loss. So regardless if one's house is insulated, if there is a significant amount of heat loss as a result of the other factors mentioned, then turning down the thermostat is not cost effective.

On average there is about a 3% savings with the installation and use of a programmable thermostat. In most cases there is no significant change in comfort levels. This is based on statistical data that has been collected over the years. To accurately calculate savings, you need the fuel billing histories, the degree days for the periods being compared, knowledge of any other improvements that may influence the savings and the settings of the thermostat for those periods.
 
  #6  
Old 05-01-05, 06:58 AM
Ed Imeduc's Avatar
Member
Join Date: Aug 2002
Location: Mountain Williams Missouri
Posts: 18,389
Wink

To set back a tstat or not to set back a tstat
On the charts I have its a lot in where you live for one thing. AS what the temp out side is. Thats like on heat down here they say you say 16%to 18% but way up north only 6% to 8% then for cool just turn it around.
In winter you can save some if you have gas or oil. With a heat pump and the older programmable tstat when it goes to pick up the heat it turns on the strip heaters so you loose all you saved On the new tstat out to day it works up slow and dont turn on the strip heaters but takes a long time to get the heat back up. On heat set back feel how cold it get in some closets and kitchen cabinets that are on the outside walls. Takes a while for them to come back up to temp.
On the AC you would be better off to let it alone . Set it and forget it. As time goes by and the home drys out some you will push the tstat up some, cause you feel cool. If you did want to push the tstat up while you are away from the home. Best to tie a humidistat in line there and let that take over the AC while you are away.

ED just my .02 cents
 
  #7  
Old 05-02-05, 03:25 AM
pgtek's Avatar
Member
Join Date: Oct 2004
Location: north Carolina
Posts: 1,391
my 2 cents

ok
why do we have cruise control on car.
It a fact when your on cruise control and keep a steady speed you safe fuel instead of of going up and down on the gas pedal.
My opinion

pg
 
  #8  
Old 05-02-05, 11:24 AM
Member
Join Date: Nov 2001
Location: USA
Posts: 1,873
The difference is variable speed with a car and a constant consumption with a heating system. For example, a car engine on cruise control will still vary in consumption depending on terrain, like going up and down hills. Whereas a heating system will go at full throttle all the time when there is a demand for heat. A heating system rated at 100,000 BTU/Hr. burns at that rate all the time, regardless if it is for one minute or an hour. In other words the amount of fuel it consumes is constant. So the only variable with consumption is time. Which means the major factor to reduce consumption is to reduce the amount of time the heating system comes on. There are several ways to accomplish this.

But for this explanation concerning the cost effcetiveness of turning down a thermostat, heat loss is the determining factor. Heat loss is influenced by temperature degree difference. We all understand that the colder it is outside, the more energy we consume to heat our homes. We all realize this when we receive our energy bills. But the reverse is also true, when it is milder outside, we consume less and our energy bills reflect it. Though we cannot influence the temperature outside, we can influence the temperature inside our homes. By lowering the temperature settings inside the home during the winter, we reduce the temperature difference between the inside and outside of our homes. This in turn reduces heat loss. And that in turn reduces our consumption of energy.
 
  #9  
Old 05-02-05, 12:26 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,752
If you have a heat pump. I vote that you set the temp. and leave it alone.

If you have a conventional furnace my call comes down to where you live (the temperature outside) and how well your house is insulated. If you live in a moderate climate and have a well insulated modern house I'd say set it and forget it. If you live in a colder climate and/or you home is not well insulated than I would get a programmable thermostat to turn down the heat when it's not needed.
 
  #10  
Old 05-02-05, 01:13 PM
Member
Join Date: Oct 2004
Location: in
Posts: 126
http://www.acdoctor.com/enegry_saver...ats_energy.htm

You can easily save energy in the winter by setting the thermostat to 68F (20C) when you're at home and awake, and lowering it when you're asleep or away.

This strategy is effective and inexpensive if you are willing to adjust the thermostat by hand and wake up in a chilly house. In the summer, you can follow the same strategy with central air conditioning, too, by keeping your house warmer than normal when you are away, and lowering the thermostat setting to 78F (26C) only when you are at home and need cooling.

Common Misconceptions

A common misconception associated with thermostats is that a furnace works harder than normal to warm the space back to a comfortable temperature after the thermostat has been set back, resulting in little or no savings. This misconception has been dispelled by years of research and numerous studies. The fuel required to reheat a building to a comfortable temperature is roughly equal to the fuel saved as the building drops to the lower temperature. You save fuel between the time that the temperature stabilizes at the lower level and the next time heat is needed. So, the longer your house remains at the lower temperature, the more energy you save.

Another misconception is that the higher you raise a thermostat, the more heat the furnace will put out, or that the house will warm up faster if the thermostat is raised higher. Furnaces put out the same amount of heat no matter how high the thermostat is set-the variable is how long it must stay on to reach the set temperature.

In the winter, significant savings can be obtained by manually or automatically reducing your thermostat's temperature setting for as little as four hours per day. These savings can be attributed to a building's heat loss in the winter, which depends greatly on the difference between the inside and outside temperatures. For example, if you set the temperature back on your thermostat for an entire night, your energy savings will be substantial. By turning your thermostat back 10 to 15 for 8 hours, you can save about 5% to 15% a year on your heating bill-a savings of as much as 1% for each degree if the setback period is eight hours long. The percentage of savings from setback is greater for buildings in milder climates than for those in more severe climates. In the summer, you can achieve similar savings by keeping the indoor temperature a bit higher when you're away than you do when you're at home.

To maximize your energy savings without sacrificing comfort, you can install an automatic setback or programmable thermostat. They adjust the temperature setting for you. While you might forget to turn down the heat before you leave for work in the morning, a programmable thermostat won't! By maintaining the highest or lowest required temperatures for four or five hours a day instead of 24 hours, a programmable thermostat can pay for itself in energy saved within four years.
 
  #11  
Old 05-06-05, 12:25 PM
Member
Thread Starter
Join Date: Apr 2003
Posts: 55
Thanks for the detailed and useful information. I've printed it out.

Taking it to my dad. I'll see if I can use it to sway him to use a programmable thermostat.
 
  #12  
Old 09-24-05, 03:14 AM
Civy
Visiting Guest
Posts: n/a
I know myself; my previous owners did not have a programmable thermostat and they were paying upward of almost 190$/month for natural gas. I know even now that I have a programmable thermostat; I have already saved 18$/month; and they haven't got around to reassessing me for my annual monthly payment (that will happen in November).

The best plan of action; definetly use the programmable options. Its quick; and a great way to save money.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes