RE: Re: Ultimate Central Heating Thermostat

[nick.broughton@xxxxxxx]

One feature my central heating currently has (installed by previous
occupant), is no internal thermostat.

If the heating is on, the control panel determines the temperature of
the water to be used in the radiators.  It does this by monitoring an
external thermometer.  There are user(installer) controllable settings
on the control panel to determine the coefficients of the equation
used.  Once set and adjusted after a bedding in period, these should
never need to be changed.  The boiler maintains the water at this
temperature.

I think this is what Patrick is talking about.

Benefits of this are;
1) the radiators are never so hot to be untouchable
2) it seems very efficient (I've always been amazed how low the gas
bills are)
3) there's no temperature fluctuation as the thermostat comes on and off

Ray's system does have some additional features that I'd also like to
incorporate in the future.

Nick



-----Original Message-----
From: patrick [mailto:patrick@xxxxxxx]
Sent: 27 October 2000 08:40
To: ukha.d
Cc: patrick
Subject: [ukha_d] Re: Ultimate Central Heating Thermostat


--- In ukha_d@xxxxxxx, REB.Barnett@T... wrote:
> Winter is nearly here, and I have a spare 5 minutes, so I've
started on the
> spec for the house thermostat I've always wanted (no commercial
product I
> can afford does what I want). My requirements are moderately
sophisticated,
> and there's a chance what I want won't work, so if anyone has any
comments
> or experience to share I'd appreciate it.
>
> *Multi-zone via Dallas one wire temperature monitors

I've been mulling this over too, and have a cunning and devious plan,
my lord. Possibly.

Traditional thermostats are deployed primarily because they enable a
closed feedback loop, with the ability to change the set point, in
the absence of more intelligent control. Does a heating control
system actually need to emulate this feedback & is monitoring of the
temperature in each zone actually necessary?

- The thermal properties of the house do not change

- The thermal properties of the house will be influenced by: sunlight
hours, external temperature, wind, rain, and insulation effects of
snowfall (which is not really worth considering in central London).

- If you have zoned control of the heating system, it should be
possibly to build a relatively simple model which takes these
influences into account, and I would guess that you could get pretty
accurate climate control based on just external temperature. From a
user interface perspective all you would need to modify is the offset
applied to each zone to raise or lower the relative temperature (...a
bit of an over simplification, since it assumes zones are
independent, but probably close enough)

The benefit of this approach is that it saves all the hassle of
monitoring the temperature in each room. There's also scope for some
nice refinements: you could get fancy, and adjust the model based on
the three day weather forecast pulled off the net. Any thoughts? Is
there a glaring flaw in my plan that I've missed?

Patrick





-------------------------- eGroups Sponsor -------------------------~-~>
eLerts
It's Easy. It's Fun. Best of All, it's Free!
http://click.egroups.com/1/9699/9/_/2065/_/972636511/
---------------------------------------------------------------------_->

<<attachment: WINMAIL.DAT>>