September | 2016 | Marsh Flatts Farm Self Build Diary

Week 50, Day 1:

A bit more second-fix plumbing, installing the WC and the flush plate for the concealed cistern in the Master Bedroom En-Suite and some other work on the plumbing systems
More second-fix electrical, including commissioning the ImmerSun Solar PV diverter which is connected to the immersion heater
- This monitors the amount of on-site generation (Solar PV power) being exported to the Grid and runs the immersion heater on something equivalent to a dimmer switch in order to use as much self-generated power as possible even if not generating the full 3kW required to run the immersion at full power
- This is expected to meet most, if not all, of the hot-water demand in the summer months, instead of running the heat pump
- Similar devices are available from other manufacturers but I chose the ImmerSun because it seemed to be the most mature solution on the market and has the best remote control and monitoring integration, uploading data to The Cloud at http://www.myimmersun.co.uk/
- Unfortunately, just after I’d bought the ImmerSun unit and its optional remote monitoring add-on, the company who manufactures the units (and runs the websites) went into administration so I was kicking myself for not going for an Open Source solution such as the one from the Open Energy Monitor Project and wondering whether the radio communications between the main unit and the monitoring add-on might use a standard protocol I could pick-up with an RFXCOM transceiver
- Fortunately the company has now been rescued and the websites are back up and running

Week 50, Day 1

Ideal Standard Playa wall-mounted WC with concealed cistern and dual flush plate

ImmerSun Solar PV diverter connected to the immersion heater

Week 49, Day 5:

At the moment a lot of the progress doesn’t show up in the pictures – there’s quite a lot of “soft” configuration of the lighting, security and heating systems where it doesn’t look like anything has changed
Since there’s a duct heater on the MVHR Supply to the house, the ducts down-stream of this need to be insulated to keep the heat inside the ducts so the air is still warm when it gets to the far end
- The “hot” water supply to the duct heater is coming from the Ground Source Heat Pump and is therefore going to be warm rather than hot with most likely a relatively small effect on the air temperature
- The small-bore plastic heating ducts are naturally better insulated than steel ducting and these were intentionally enclosed in the inter-floor insulation (more intended for acoustic rather than thermal purposes) so it’s really just the steel ducts and plenums in the Plant Room that need insulating
More work commissioning the lighting systems
- Now all of the internal downlights and wall lights are installed and working, with just the LED strip lights and most of the outside lights to go
- In the evening I completed the basic KNX programming so that the ceiling-mounted PIR switches in the bathrooms and hallways / landings control the relevant lights and the relatively small number of wall switches control the main lights in each room
- The Up/Down light on the Balcony (a Nordlux Canto Maxi) has a pair of (allegedly) dimmable 5W GU10 LED bulbs controlled by an Aurora AU-DATR400 mains-voltage DALI dimmer. Compared to the excellent dimming behaviour of the internal lights with their separate DALI dimmers this combination isn’t anything like as good. More investigation required.