remote temp sensors instead of programmable stats in each room

[mistadave]

Hi All,

I have been looking around for heating controls for my house renovation.

Basically I want something that can control heating of up to 8 zones, I have UFH downstairs and rads upstairs and all will be controlled on actuators.

The nearest i have found so far to what I want is Heatmiser's network system, but all I really want is one central programmer unit with access via a web browser or failing that just a big control screen, and the one unit has small temperature sensor in each room. On the heatmiser system you have to have a big ugly programmer in each room - basically i just want one programmer that does 8 zones, not 8 programmers that only do one zone each.

Any ideas would be much appreciated!

[mistadave]

Ohh how rude of me, I've been browsing this forum for so long I thought I had posted before!

Hello Navitron Forum, and thankyou for all the fantastic information I have received so far!

[dhaslam]

You could use a one wire system  and a computer program  to operate the relays for the separate circuits.   However the  software isn't easy to write.   It would be  better than a standard system because  you could pre-program various options that can be triggered by outside temperature  etc. 

I have  Danfoss 5000 Si s in all rooms including  bathroom ones with remote sensors.  The mains voltage wiring was  done while the house was being built.     The two  bathroom ones failed  plus all the supplied Sony batteries but otherwise they work well.  Because the house is so well insulated  only a two or three circuits are used normally so  they don't have all that much to do  but when needed they can control the temperature within about .5C.

[wookey]

I'd do it with 1-wire and HR20s plus a little linux box (in fact that's my plan - but it's all got stalled rather by extension building).
The completely obvious solution you want seems sadly unavailable generally. The only  commercial supplier that might supply what you want without spending crazy money is alertme.

[hiccup]

Hi

There are very few commercial off the shelf systems that hit all of your requirements. Kanmor comes close but still has a "room thermostat" in each room although you can  probably mount the sensor remotely from the thermostat. There was another system available a few years ago but you needed a big lottery win to afford it.

This is why a few of us on here are growing our own systems.

Mine is based on 1 wire sensors with the actuators on the manifolds controlled by a Barix Barionet connected via ModBus to some R6 relay modules and some custom built multi I/O modules for controlling the HRV unit, boiler, and other bits. The Barionet is then in turn controlled by some python (well quite a lot really) running on a linux server that integrates the heating, solar-hw, HRV, security and other systems around the place.

At least, like Wookey, that's the plan. I keep getting distracted, but most of the hardware is now in place and I'm working on the python to control it all.

Happy to discuss ideas further

Hic!

[billt]

Heatmisers new Wi-Fi thermostats are remotely accessible, so could be suitable if you can stomach the price.

I'm very reluctant to roll my own heating control system; in my experience PC based systems are less reliable than purpose built ones, mainly because of the tendency to keep tweaking the system. If you want to sell the house in the near future, the simpler the control system the better, and DIY ones won't be attractive to potential purchasers. And if you want to stay in the house for the rest of your life, you might forget how the system works!

[HolmWood]

I have a similar problem, I have Solar Thermal Store [just installed] and want to replace my [very old] gas backboiler with a gas boiler to feed the central heating, with motorised valves to switch the heat into the store when it calls for heat and there's no sun [like now].

A visit to the Worcester Bosch [WB] showroom [in Worcester] identified that I can't use any WB fancy controls and thus have to use external controls [I think it's because their system runs on low voltage and the motorised valves are mains]. The technical specialist said that because I want to run the boiler that way it becomes a heat only boiler and it needs third party controls; he suggested Danfoss or Honeywell. Danfoss website not very helpful but the Honeywell website with their RF units look the dog's danglers.

http://www.honeywelluk.com/Documents/All/pdf/Application_Manual.pdf
http://www.honeywelluk.com/Documents/All/pdf/1064.pdf

They mention OPENTHERM-Bridge for boiler control. I understand that OPENTHERM-Bridge is an interoperation standard, but am having a problem identifying a boiler that does this. Was considering WB or Vaillant.

There seems to be more to it than just specifying a boiler, I understand the difference between vented and pressurised, but there is flow rate, TPI, external temperature compensation, set points, zone control etc etc. I want to get my head round this before contacting a plumber since there's no guarantee that they'll be aware of what's do-able [don't want a  -nah mate I just fit boilers don't know nuffink about no fancy controls;  - ok I'm sure they're not all like that, but I don't want to be pressured into buying something that is not suitable]

One wire is quite inexpensive, but you need coding skills to make it do what you want
http://www.sheepwalkelectronics.co.uk/products-components.shtml
provide bits and the basics

DigiTemp is a simple to use program for reading values from 1-wire devices. ..."
www.digitemp.com/


Googling one wire with linux will bring up lots of sites which may be of use to you.

Anyroad, Honeywell RF units appear to do what you want, only problem is the likely cost. I want to check if I can fit simple Honeywell rad valves now, and can I add the intelligence onto the valves later.

HTH

[artful_bodger]

I'm a real fan of technology and there's nothing I like doing better than buying something plugging it in, messing with it for hours unsuccessfully, getting more drunk and angry with the designers until I've read the manual.  Then I spend the rest of my life tinkering with it to make it work 110% perfectly, or until I get another new toy.  So read 99% and new toy.

I love the idea of UFH and individual zones/rad upstairs.  I seriously looked at it for my last renovation and I'm glad I didnt as the investment was huge and I would never have acheived the savings unless I'd died in the house.  As it happened I sold up in 3 years. 

Having bought both branded and unbranded TRV's I'd personally plump for cheap ones on every rad.  They all gum up after 5-10 years.  For a mechanical device they are reliable and control the temperature well.  I would, however, recommend good quality valves on the other side of the rad, as the cheap ones do leak very quickly.  I'd spend the money saved on beer, err, I mean getting cavity wall insulation. £200 well spent.  The the remaining £500 the missus will blow.

[Baz]

Have you looked around home automation forums for ideas? There are some self contained home control units with simple interfaces and displays so no need for a dedicated controller.
You might find a horticultural controller that has multiple zone control.
People are attracted to wireless because of the idea of 'easy fit' but as people find with wireless broadband  British houses with solid walls and foil plasterboard present major problems for the signal. Also electronics placed next to a hot radiator is going to have a short lifetime.
Long term it would be better to get some hard wiring in, use standard TMVs so it can work conventionally to start with (not that TMVs have an infinite life/reliability) and override the TMV with a 1W resistor heater. Wire up with phone wire between a central control point and a junction box in each room so you have several circuits for radiators, thermostat, temp sensor, occupancy detector.
Get the simplest possible boiler with just on off so you are not tied to a fancy built in controller that always seems to have been designed by a geek with no human interface skills.

[martin W]

sort of jumping on the band wagon here.

irrespective of the control and sensing system, most domestic heating system are still wet and rely on radiators or under floor heating. Are there cheap soleniod (or motorised) valves available? In therory for an efficent heating system you want each room to be zoned. 

thats easily 8-10 motorised or soleniod valves - alot of expense at £30-40 per 2 port valve...

[martin W]

Just thinking on it, it would probable be best to use a motorised valve in doemstice settings as you can use the actuator switch to turn on the heating pump / boiler etc. If you just used a solenoid valve we would have a problem if the valve did not actually open and the pump was running.....


anyone know if you can by standard soleniod valve with proof of open position?

[Countrypaul]

sort of jumping on the band wagon here.

irrespective of the control and sensing system, most domestic heating system are still wet and rely on radiators or under floor heating. Are there cheap soleniod (or motorised) valves available? In therory for an efficent heating system you want each room to be zoned. 

thats easily 8-10 motorised or soleniod valves - alot of expense at £30-40 per 2 port valve...

Am I missing something, but surely this is exactly what a UFH manifold does for you?

Paul

[pb]

irrespective of the control and sensing system, most domestic heating system are still wet and rely on radiators or under floor heating. Are there cheap soleniod (or motorised) valves available? In therory for an efficent heating system you want each room to be zoned. 

thats easily 8-10 motorised or soleniod valves - alot of expense at £30-40 per 2 port valve...

BES sell 2-port motorized valves for £18+vat or thereabouts.  Or you could use a UFH manifold with electrothermic actuators: you can get an 8-port manifold plus actuators for around £120+vat, which is about £15 per port.  So not exactly cheap but not quite as bad as the £30 you mentioned.

Both of these have the disadvantage of using significant electrical power all the time the valve is open.  To avoid that you need to use a motor-on-motor-off type valve which, unfortunately, do seem to be rare and expensive.

[pb]

Just thinking on it, it would probable be best to use a motorised valve in doemstice settings as you can use the actuator switch to turn on the heating pump / boiler etc. If you just used a solenoid valve we would have a problem if the valve did not actually open and the pump was running.....

That's true, though a lower-tech solution would be to fit a pressure operated automatic bypass.  That's only about a £7 part and doesn't add any control complexity.

[martin W]

opps, I didnt realise that you could buy electrically valved UFH manifolds, only seen the manual type...

hm... just realised you'd need a motorised on, motorised off valve, or at least a double acting soleniod valve which I suspect is not normally availble for water systems to save the electricity.

The automatic bypass does save the pump if  the valve doesn't open, but the pump might still be running when no radiators or UFH circuits are actually open due to faulty valves.

are we talking 1 or 2 watts to hold a soleniod or motorised valve in the open position, or 5-10 watts (or even more )