Passivhaus new build - help needed!

Hi everyone,

My energy consultant recommended using the openenergy equipment for house monitoring so I am just starting to look into it, whats involved, what I would need etc. and thought someone might be able to help.

So we are mid way through the construction of what will be a certified passivhaus. We are building a house with detached garage and planning to install PV panels on both roofs to approx. 11kW array. We are having a 3 phase supply which will feed into the garage, one phase will run the garage with a 4kW array and the other two phases will go to the house running 2 x 3.5kW arrays. Obviously these phases will run lighting, sockets etc. also.

I would like to be able to monitor electricity generated, usage and the amount exported. Also thinking out loud, I would like to monitor temperature/humidity upstairs and downstairs (possibly individual rooms), external temperature/humidity, slab temperature in a few places (if possible), MVHR inlet/outlet temps, plant room temp (under the stairs cupboard!), ASHP temp/usage,

If someone could point me in the right direction as to what I would need for this that would be great! At this stage I just want to make sure I have enough sockets in the right places before we start plastering although it seems most of these units are battery operated.




Robert Wall's picture

Re: Passivhaus new build - help needed!

It certainly sounds do-able.

At a minimum, it look as if you wil want 3 × emonTx, one per phase, each will give you the true nett power on that phase and you'll have 2 high power and one low power current inputs left over, one you will use for the P.V> and the remaining two can be used for individual circuits. Each will need a socket on the phase you are measuring the voltage of.

You can add a handful of emonTH's (battery powered) for the individual rooms. If your garage emonTx is near an outside north-facing wall, you can add an external temperature sensor to that, otherwise it's another emonTH but it need a ventilated and weatherproof enclosure.

For the other temperatures, if they are reasonably close to an emonTx, you can add many temperature sensors to each.

To record and make all of this available, you'll probably want an emonPi (which can replace one of the emonTx's if it only uses two current inputs), but that will need a second socket for its 5 V power as well as the one for the a.c. measurement. If you don't want to replace an emonTx, then a plain Raspberry Pi and the RFM69Pi radio and the software will do the job (and that needs a 5 V supply too).

The main thing to think about at this point is the wiring you'll need - for temperature sensors in particular and maybe Ethernet connections to your router, if WiFi isn't viable. The emonBase (the emonPi or RPi) needs to be within radio range of all the emonTH's and emonTx's. If you have foil-backed insulation, that could be a major problem and we'd need to think of wires rather than radio, and that would be a nightmare once construction is finished. 

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