modern house heating control [LWN.net]

modern house heating control

Posted Oct 11, 2013 0:19 UTC (Fri) by giraffedata (guest, #1954)
In reply to: The Thing System by rmayr
Parent article: The Thing System

What is it about heat pumps and proper insulation that means you don't want the house to be colder when you're at work (or asleep, I suppose)? Are you saying it takes all day to change the temperature a few degrees?

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modern house heating control

Posted Oct 11, 2013 0:54 UTC (Fri) by dlang (guest, #313) [Link]

maintaining a temperature difference between the house and the outside when there is no need to do so costs money and power. (nobody is home so comfort isn't an issue, pets and equipment are able to deal with different temperature ranges than we consider comfortable)

Insulation and heat pumps don't change this basic fact.

Insulation changes the rate at which the inside equalizes temps with the outside, and therefor the amount of heating cooling needed to maintain the temp difference. Heat pumps are relatively efficient tools to maintain the temp difference (at least under most conditions), so they reduce the cost.

but by far the most efficient thing to do is to not maintain the temp difference when it's not needed.

modern house heating control

Posted Oct 11, 2013 6:35 UTC (Fri) by rmayr (subscriber, #16880) [Link] (3 responses)

Yes. In my own house as an example, with a temperature difference of roughly 20°C between inside and outside, inside temperature will decrease by about 1°C over the day when heating is turned off -- even less when the blinds are down, or it might actually increase by 2°C when we have autumn/winter sunlight coming in through the windows throughout the day (large areas of glass and proper insulation will do that to you). This is so close to measurement error and on/off hysteresis width that it simply doesn't make any sense to turn off the "normal" mode during the day.

Combine that with the fact that heating pump systems have a (realistic, not placebo) reaction time of >2h between turning on the heating system and actually making a difference in room temperature and you'll see the big difference between "modern" houses and old 1-glass-pane-windows-with-gas-heating scenarios (in which an elaborate control of heating makes sense, but those houses will probably lack the infrastructure to do so).

However, all of this is a complete tangent to the original article, and I am sorry for even bringing it up. I just get bored by the same examples for smart houses that have been used for the last 15 years (yup, I've been to ubiquitous/pervasive computing conferences for a while) and that just don't make that much sense.

modern house heating control

Posted Oct 13, 2013 19:42 UTC (Sun) by jzbiciak (guest, #5246) [Link] (2 responses)

If you had computer-controlled blinds, it might make sense to control those, either to maximize incoming sunlight in the winter, or minimize it in the summer, except in occupied rooms of course. This is an extension of the lighting theme, but applied to natural lighting which also doubles as a source of heat.

modern house heating control

Posted Oct 14, 2013 12:23 UTC (Mon) by mathstuf (subscriber, #69389) [Link] (1 responses)

There's also the question of what does "occupied" mean in a house with pets. For lighting, probably nothing changes, but cats do like to lay in sunlight (even in the middle of summer), so for cats, calling it occupied for blinds could make sense.

modern house heating control

Posted Oct 14, 2013 13:06 UTC (Mon) by jzbiciak (guest, #5246) [Link]

My cats, at least, have no problem climbing directly into the window sill, behind the blinds. ;-)

But yes, pets do throw things off a bit.