Andy Hall wrote:
On Wed, 28 Jan 2004 22:33:45 GMT, Velvet wrote:



I keep the house to a fairly normal cycle of heat even when I'm not
there for a weekend (tend not to be gone any longer than that) because I
have pets who, though they'd no doubt survive, would take a while to
acclimatise to lower temps, and then have to acclimatise to higher ones
again - and other pets who will simply end up with their own heaters
running constantly to keep them up to temp. With that in mind, the stat
never sets itself below about 12C at any time day or night, and while
daytimes are cooler than if I'm around, they're still no lower than 16,
with a burst of a couple of degrees of an evening.

My previous experiences with letting a house cool to around 10C is that
it took hours, literally hours and hours, to warm back up again.
Possibly even longer than that - a day, maybe. It wasn't this place so
I'm not sure how much of that was the heating (different system, not
going to start an argument so won't say what it was).


I'm perfectly happy with the stat dropping to 11 or 12 overnight,
because at the moment (well, before this recent cold spell) it's never
got down beyond 14 or so. Me personally I don't mind if it drops below
that, cos I have a thick duvet and prefer a cold rather than hot room to
sleep in. But getting up in the morning I'm conscious of how long the
heating runs for to bring it back up to temperature, vs how often and
long it runs for if it's just maintaining the steady temp.

That's how I got to wondering which one actually does use more gas, and
therefore, costs more... and searched the web, but to no avail, no
concrete examples and theories that demonstrate the differences between
the two methods seem to exist. And whilst I'd give it a go as a home
experiment, I know the weather's too variable to make the results
worthwhile.

Oh well. Ta for the replies. Anyone else?


Well...... you've introduced additional information that you have
animals who require an environment influenced by the room temperature.

If there are a significant number of them or more to the point their
enclosures and the energy requirements, then the cost difference of
energy for the house may well become irrelevant. If the heating for
the enclosures is electric, then that is costing 3-4 times the gas
cost anyway.

If economy is a real issue for you, then insulating the animal
enclosures makes sense.

I've done this for an enclosure housing two creatures who like to have
an environment of about 29 degrees and 80% humidity. It was a
challenging project, but I made a significant difference on
electricity use with insulation to avoid heatloss to the room.






Velvet


.andy

To email, substitute .nospam with .gl

That's an interesting point. In my situation, it's only one that'd
actually cost me more financially (potentially) - tropical fish tank. I
found somethign that gives an estimate of cost/month based on wattage of
thing, and hours run, which was quite handy. Need to establish what the
heater wattage is of course, then it'll be a stab in the dark for how
long it actually spends running.

The majority of the other critters wouldn't mind, but a couple of them
would be prone to getting far more chilled than they should, and lack of
'freedom to roam' if I'm not there means they can't use exercise as a
means of keeping body temp up. They don't have any form of heating, cos
there's absolutely no way to stop it escaping straight into the room.

I'm still really looking for a fairly simple explanation of the energy
used to heat a place from a colder temp, vs energy used to maintain a
temp. Someone somewhere must have done the research for this, I just
can't find it :-) I thought maybe there were lurking people here who
had the physics etc knowledge to calculate this sort of thing, I was
thinking it was something that people might know from sizing CH systems
since you have to generate enough heat to actually get the place warmed
up in the morning, but I think I'm realising that the efficiency isn't
looked at in an overall sense like this but more as an 'insulate as much
as possible then fit the most efficient boiler' - just seems there's a
bit bit of the puzzle being missed out, which is how to run the CH most
efficiently.

Off to google again for more physics based stuff I think!

Velvet