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jelle.kalf.org/2011/01/home-automation- ... 011-plans/

Happy reading. Any tips/comments? Please add them to the comments of the blogpost. I'll post link-backs to this thread.

Today I got a nice big package from the guys over at ELV. It contained a EM1000-wz building kit, a FHT8v, a FHT8w building kit and 3 units of FHT80TF-2.

I can't use them yet as the FHT80b-3 kits were out of stock, but I chose the split delivery as you can see I have 2 building kits ordered. It saved me a total of € 40,-- and gives me some fun building it all.
Here's the building of the EM1000-wz:



Sadly though, I now have to wait for the CUNO to arrive, it's not in stock and they don't expect it in stock before the 10th.

Tomorrow is the FHT8w building day. That should be very fun

What can you do with those? I don't know all the article numbers yet.

The EM1000-wz device uses an ir led to watch that black/red spot on the wheel spinning in your energy meter. Yes, I have an old one . It transmits it's data via 868.35MHz OR via a 5v pulse wire exit.

I'm going to use the radio transmission option.
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The FHT8w is a 868,35MHz boiler relais device. It'll be paired with my FHT thermostats to turn on the CV or (in my case) send a signal to the honeywell valve that controls the flow of hot water in my district heating pipes.

Thanks!

Just received my last batch of ELV goodies. The FHT80b (thermostats) and the complete kits have arrived. You can buy the FHT80b-3 with a radiator valve (fht8v-2) and a windowsensor (FHT80TF-2) which is cheaper then buying them seperately.

Ohh lordy, my misfortune.

One of the FHT80b units I ordered seems to be broken. On the very good side, ELV is very keen on this and directly asked me to send it back so they can replace it. Kudos for them for picking it up like this.

The other units are now installed in my house. At least, the thermostats and the windows sensors. The FHT8v-2 (radiator valves) aren't installed yet, because the company that build the house has used a standard size thermo-valve. With "standard" being his own standard.

The thread of the coupling is about 2mm short, so the FHT8v-2 can't be installed onto it. I have to drain my system:


Now I have bought a new "el cheapo" thermovalve set, they cost about € 15,99 at the Praxis (DIY shop)


as you can see, the thermohead of that valve is cheap as h*ll, but I need everything but that part so I'm in the clear. The rest of the device is solid.
Comparing this image to the previous one, it'll seem that both couplings are the same size. They are, except for the metalwire part where you hook the RF device onto. It's only 2mm, but enough to not fit

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On the bright side, I've had time to solder the FHT8w boiler relais together. That's the actual switch turning on/off the waterflow of my district heating:

(for the observing viewer: in the right back you'll see an IO-bridge lying around on the NAS)

And here's an image of everything neatly packaged in IP-65 housing:


What's next?
Call my nephew to come over for a cup of coffee on a saturday and ask him if he could bring along his van. (He's a handyman by profession)
Drain the pipes, replace all the valves and hook up the system.

I've had a few brainfarts and I've run them by KidE to see if they could be implemented.

Energy savings
My district heating circulationpump uses about 40w of power 24/7. Seen that it's only effectively used when either the heat is turned on to warm up my house, or when I require hot tap water (the circulation pump is used both for central heating as for hot tap water), KidE pointed it out to me there might be a better way of controlling it's power consumption.

Basic central heating
I'm not going to cover this again, it's in this subject already. I'm implementing the FHT solution and the flowvalve of my district heating is handled by a FHT8w. In the first implementation idea the circulation pump would be running 24/7.
Special remark: The FHT8w sends an on signal on a 15 minute timer. If it requires more then 15 minutes, it'll send another signal. THERE IS NO OFF SIGNAL sent from the FHT8w device!! <-- very important, keep this in mind.

problem no.1
1- If I turn the circulationpump off by default, the FHT8w will be able to open up the flow valve using the internal relais, but no water gets circulated through the system.
2- If I turn the circulationpump off by default, I also get cold tapwater instead of warm tap water.
I can't put both the pump and the flowvalve on the same FHT8w device as there's a distance of several rooms/closets to cover.

Brainwave 1 - FS20 WS1
Put a sender module in the FHT8w and let it remotely control the circulation pump with a FS20 signal to a FS20 WS1 while using the internal relais to switch the flow-valve.

• Error 1: The FHT8w can either use the FS20 send module or the internal relais. Not both at the same time!!
• Solution to error 1: program another FS20 WS1 device with the same adress as the circulation pump FS20ws1 device. That way the FHT8w will trigger both with an ON signal when heat is required.
• Error 3: If the FHT8w triggers the FS20 WS1 to turn on for 15, it will never go off. It seems to be a dumb receiver device that switches on or off. It doesn't seem to have a timer functionality. (I couldn't find it in the documents).
• error 4: if the central heating system doesn't require heat and the circulation pump is off, I'm getting a cold shower.. brrrrr
• half solution to error 4: build a reflux valve and a flow sensor into the tap water pipe that flows through the circulation pump to get heated. Hook this flow sensor up to a pulse device that triggers a FS20 signal to turn on the circulation pump.
• Error 5: If we require hot tap water, but no central heating, we have an issue: If we trigger the circulation pump to go on, the flow-valve of the central heating system will also turn on as it is on the same FS20 address. We spend too much on circulation water in the central heating system while it's not required.

brainwave 2
FS20 SW1 seems to be bad as we can't turn it off in time. What does the FHT8w documentation recommend: use a FS20 AS1. (or at the same price in a smaller non-IP65 package the FS20 SU)
These 2 devices support the FHT8w way of turning the device on. Turn it on, for a specific amount of time. The device does not require a OFF signal.

• Error 1: the FS20 AS1 only switches 1 relais, not 2.
• Solution to error 1: Buy 2 FS20 AS1 devices.
• Smart question: so now the FHT8w can simultaneously switch both FS20 AS1 devices. What about the hot tap water problem?
• Smarter answer: The FS20 AS1 has to option set multiple FS20 addresses to 1 switch. As long as I only use the SWITCH on with a timer function, and not use the OFF signal it will work in all cases.

For now I came up with this little drawing. (I've used the FS20su in the drawing, but FS20 AS1 is the same):

big update. I've put a part of this brainfart to the test with the ELV guys. I really wanted to know for sure that the FHT8w situation with FS20 and the internal relay wasn't working. They gave me a quick and nice response back:

ELV techy! wrote:"the internal relay is always switched according to the heat demand, regardless of whether the additional release of FS20 command is active or not. Thus, the switching by radio and by FHT8W no problem."

So I've updated my drawing again and thus saved me about 30 euro's.


Now for the more difficult part. How the heck am I going to get a flow sensor into my hot tap water pipe, without it being effected by cold tap water requirements (I'm thinking of a reflux valve "terugslagklep") and to get it's data translated into a usable FS20 command.

Jelle,
Did you also have a look at the fs20 ZPS? Wouldn't that be of any help?

Alexvanhoboken wrote:Jelle,
Did you also have a look at the fs20 ZPS? Wouldn't that be of any help?

Hi Alex, the ZPS won't be of any help to me. It's a sensory system requiring a hot/cold zone. When I'm not requiring hot tap water I'll always have 2 cold zones, which will trigger the ZPS to turn on the pump. <-- doesn't sound very good to me.

I will need a flow sensor of some kind. Any other thoughts that might help? I haven't found a solution myself either.

After doing some research i think a flow sensor wouldn't be the ideal solution for this. If you would mount a pressure switch in the hot and cold rings these would register a drop in pressure when the tap is opened. This signal could be used to trigger the switch that sets the pump