[OpenTRV-dev] Basic V0p2 operation

Mon Oct 21 19:01:18 BST 2013

how are the different heating stuuf connected?

one way i know it can be done is that everything is connected in series 
together with a storage tank (last can be an old 1000 liter oil tank for an 
oil burner - well insulated of course)

so the solar water and and gasburner just heats the storage tank and then 
the rads can be feed directly from that one...

hot water tank (with built in heatexchanger) can also be feed from there...

but loads of options... why i was thinking this was that you said the setup 
is complicated....


-----Oprindelig meddelelse----- 
From: Stuart
Sent: Monday, October 21, 2013 4:25 PM
To: Damon Hart-Davis ; Closed list for developer discussions
Subject: Re: [OpenTRV-dev] Basic V0p2 operation

Very helpful. So it is a jazzed-up FHT8R? with some local control?

The missing link for me is connecting FHT8R/FHT8V to boiler control and
weather compensation. My current project is weather compensation and
condensing boiler temp control (to ensure full condensing) with a web
interface.  It is very simple, and uses temperature sensors and controls
the boiler via the heating thermostat (prototype hardware 90% done,
mainly the html to do).

OpenTRV would add the individual room demand to that thus allowing the
boiler go and return circuit to go completely cold if no room demand,
rather than be kept at temperature with boiler cycling, controlled only
by one thermostat in the hall. So a better match between boiler output
and demand, with savings coming from the use of precise individual zone
time and temp controls rather than (crude) TRVs.

The purpose of my web interface is so that instead of setting schedules
on devices in fiddly little plastic boxes, you can sit in front of the
telly with an ipad and set things up at leisure with a nice interface.
Even with the web server the prototype is cheaper than a Worcester Bosch
weather compensator controller.

Ultimately I plan to include DHW but that is complicated by the solar
pv/immersion and solar water inputs that I have.

A small point about the FHT8V, it has a 30mm fitting and replaces recent
TRVs but not older ones (e.g. Drayton TRV3) with different threads.
Their adapters are not comprehensive (I'm having to modify an adapter
for my TRV3s), though mostly I have TRV4s, fortunately.


Stuart Gillies

On 21/10/13 12:20, Damon Hart-Davis wrote:
> Basic outline of V0.2 design operation at Stuart (G) suggestion:
> http://www.earth.org.uk/open-source-programmable-thermostatic-radiator-valve.html#V0p2Basics
> Rgds
> Damon

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