Arduino and home heating help/ideas

yfaykya

Hi,

I currently have a multi zone central heating setup and was thinking of making it smart. I looked at off the shelf stuff like honeywell and heatgenius but I think they are over priced and better fun to do it yourself I reckon!

So currently I have 8 zones downstairs with thermostats (Danfloss TP4 - wired - 2 wires) that feed to a "control plane" that the underfloor actuators connect to:



These is a feed from this to a Zelio Logic PLC (SR1 A201FU) that controls the boiler:



There are also 3 other zones :a hot water zone, downstairs bathrooms and upstairs rads which all feed into the PLC also. The PLC opens motorised valves to feed each zone.

I was thinking of connecting the arduino in instead of the PLC and then adding an ethernet port. Then allowing control from web/app from phone as well as still having the thermostats controls in the rooms.

The upstairs is all one zone at moments so I would also like to swap out the TRVs on the rads there and perhaps use some smart ones with Z-wave or similar.

Has anyone attempted anything similar? Any ideas/caveats etc?

I am newish (hacking for a long time but never did anything substantial like this) to electronics but a decent comp dev (imho!).

Thanks muchly.

Chet T16

Perfectly doable. All you're going to be doing is turning on and off relays to control the valves. You can get some motorised rad valves for upstairs if you want individual control.

What do you want it to do that is doesn't do now?

yfaykya

Chet T16 wrote: »

What do you want it to do that is doesn't do now?

Hi there! Thanks for response. I would like to add control of the upstairs rads. I assume wirelessly.

Also I would like to have central control of all zones. Don't have that now. I would add in rules similar to Nest etc that will look at warm up times etc and weather conditions to make better decisions.

Also would be great to keep historic records of times each zones were on etc to display charts. I have quite a few computers in this house on 24/7 (media players/NAS etc) so I could offload decisions/processing there quiet easy. It is more the electronics side of things and what way to control the arduino (or PI or whatever might be more suited - I picked arduino as I have a uno at moment).

Thanks for reply - I am quite excited about taking this on even if I make a mess of it :-)

Chet T16

You can add motorised valves to the rads, you can get either mains powered or 24v.

You are going to need temp sensors in each room and a way of getting this information back. Wired is always better, is that possible?

Offloading the processing is the way to go, get that running wherever your strengths are and feed it back to the arduino to act on - all thats going to need to do is be told which outputs to have on or off.

yfaykya

Wired will prob not be an option for the rads upstairs. I was hoping to get some sort of a wireless TRV with a stat built in and then calculate an offset from that temp (as it will be on the rad!) for the room.

The downstairs UFH is already wired to thermostats so no worries there.

I have an arduino uno at moment so might need a bigger one with more inputs/outputs. I also need to look at getting it on the network (there is an ethernet switch in the room where all the stats feed back to so cabling will not be an issue there).

At moment there are 8 stats downstairs and if I zone upstairs how I want to I will be adding 4/5 more.

I'll do some googling on potential wireless rad controls.

Thanks for replys!

yfaykya

This looks interesting :

http://opentrv.org.uk/

DublinDilbert

Looks interesting and I love arduino projects but would you consider just updating the plc?

You can get a micrologix plc with Ethernet for around 300 new and a lot less on ebay.

If you want to use an arduino you could still use one to talk to the plc and maybe run a webserver which will allow you adjust settings.

yfaykya

I want to add z-wave etc. What I have ended up doing is buying a Pi and a Razberry z-wave module (and some z-wave thermostats for rads upstairs).
I have taken a lot of the wiring apart and figured out how it currently works pretty much.
Each downstairs thermostat is just a relay for 240V. These all feed back to a another relay that talks to the PLC and turns the boiler on. The boiler feed is also 240V.

I have bought a relay for the PI (AC one) so I can control the boiler from there. I was hoping to run DC to the thermostats and feed then back to the PI GPIO pins like a switch in essence. I am hoping that 3.3v is enough to travel around the house with out issue. If it is a problem I can keep the AC and the relay I bought is 16 channel so would be able to cover that.

I will then set up homegenie on the pi to control the z-wave rads upstairs and the UFH heating downstairs. I can then override the thermostats from the PI also. This also allows me add lighting etc in time.

Anyone see any issues with my notions? :-)

Thanks.