On 1/15/2015 8:19 PM, Nil wrote:
On 15 Jan 2015, Tony Hwang wrote in
alt.home.repair:

What is the temp. you set for sleep?

60 F.

'stat needs some time to learn the pattern. After a few days it'll
learn how much it takes to bring up the temp. from sleep to wake
and gradually adjusts it. Isn't it logical, is it?

Is it logical that it should take almost a week to adjust, is it? Is it
logical that it should come on more than 3 hours early, is it?

I always used Honeywell 'stats and my favorite is Pro 8000 series.
I am using wireless one at home now. You are a bit impatient,
aren't you?

I don't think so. You are a bit impertinent, aren't you?

Might be interesting to run some experiments to graph temperature
decay time from 70 to 60 and back from 60 to 70.
First tells you how much heat you're losing. Second tells you how much
you're adding. The difference should tell you something about the thermal
mass of the house.

My thermostat has the smart predictive on-time to get the house at the
right temp at the right time.

I have a running graph of the on-time of the furnace.
It's sensitive enough that I can see the % on-time throttle back
when I get up and turn on my computer.
After watching it for a while, I convinced myself that the amount
I saved during the setback interval was only slightly more than the
energy it took to heat all the thermal mass back up.
I turned off all the automagic stuff and set the thermostat for 66F.
The better your insulation, the less you save with setback.
The more you're home, the less you save with setback.