Opinions needed

Unknown

Thank for the info man.
I'll check it out.

Unknown

Fuel Opinions needed

Which will cost more in fuel oil, Maintaining a home @ 65 degrees at all times, or going into setback for 8 hours to 60 degrees then bringing it back to setpoint ?

If it takes 45 minutes for the boiler to recover fully, will the times it comes on after the 8 hour setback be less than the time on needed for the boiler to maintain temps ?

Brad White_185

If

If when you say that the boiler recovers fully in 45 minutes, I assume you mean that the house temperature recovers in that time. Correct?

Assuming that is so, what happens from the moment your house goes into setback?

(Say on a day halfway between design outdoors and comfort or the no-heat-needed point as an average).

Does the temperature holds steady more or less and drops off gradually?

Does the temperature drop like a rock and the boiler fires to low space limit?

How long does it take to reach the setback temperature?

Does it indeed ever get from 65 to 60 during your setback period?

If you recover your house temperature in under an hour, count the number of hours your boiler sits idle during setback periods. I think you will find your answer.

A data logger (onsetcomp.com is one company I deal with) can set you up with recording loggers for temperature and for burner on-time. With this you can track hours of run time at all indoor and outdoor temperatures for a more definitive answer. A 45 minute recovery is not bad in my estimation though, but your system may be over-sized.

realolman

Some times

You can't see the forest for the trees.

I made this computer program and hooked up these sensors to my boiler to try to get a handle on my fuel usage.

I'm wondering why I have been unable to reach a satisfactory conclusion. This thread caused the bulb to light... because you don't have any comparison data! duh!

I put the programmable thermostat on "Hold" at 71° for one day so I would have something to which to compare my setback data. It is normally set back to 68 at night and while we're at work.

Temperature is across the bottom, gallons of oil up the right side. Each dot is one day's average temperature and fuel usage. The one day with no setback is in red.

I will try it for one more day, but if it looks similar to this one, that's it, I don't want to use the fuel.

Edit... since no one replied I will just edit this to show what happened on the second day. That's it... back on the setback program.