I have an F1255 Nibe heatpump in my home which I’d like to read out and possibly automate/optimize. Here I document my approach.

Goal ¶

1. Show live performance of the heatpump (e.g. power/COP) during both heating and cooling
2. Optimize consumption to either low electricity price (via epexspot (epexspot.com)) or low carbon intensity (via co2signal (co2signal.com)?)
3. Optimize electricity consumption / COP by tuning parameters

Setting up hardware ¶

Hardware setup ¶

There’s a few (hardware) options for reading out the heatpump. I chose a pre-built LilyGO T-CAN485 ESP board (opencircuit.nl) with esphome-nibe (github.com). Other options are listed below

Raspberri Pi with Modbus ¶

Hardware (total: 52 EUR):

• RPi W (19 EUR (kiwi-electronics.com))
• RS485 Pi (18 EUR (kiwi-electronics.com))
• 12V input shim (15 EUR (kiwi-electronics.com))

Software: nibepi (github.com) OR using nibe (github.com) and nibe-mqtt (github.com) libraries

Arduino/ESP32 with Modbus (preferred) ¶

Hardware (total: 17-36 EUR):

• Arduino R3 clone (10 EUR (tinytronics.nl))
• Arduino R3 (25 EUR (tinytronics.nl))
• DFRobot RS485 shield (dfrobot.com) (11 EUR (tinytronics.nl))
• Grove RS485 (7 EUR (kiwi-electronics.com))

OR a combined board:

• LilyGO T-CAN485 (20 EUR (opencircuit.nl))

Software: esphome-nibe (github.com)

Pre-built PRODINo ¶

See here (kmpelectronics.eu) or here (web-engineering.info)

Installation ¶

For details, read the installer manual (nibe.eu). First remove the front panel of the heat pump with the two TX25 Torx screws at the bottom, then tilt the panel and lift up (see page 8 of the installer manual (nibe.eu)). See page 12 for the location of the distribution boxes, and page 20 on how to open it (specifically: box AA3). Below a few pictures of my setup

An overview of electrical diagrams is available here (nibe.eu) (Dutch). here, you can see you need to connect 9-10-11-12 (GND-B-A-12V) on print AA3 rail X4. Alternatively, see the Nibe Modbus moduledocumentation (nibe.eu), or this topic (energiesparhaus.at). In my case there was already a wire connected to the pins (blue/yellow/green/orange wires to 9/10/11/12 = GND/B/A/12V), but it was not connected on the other side (?). I used this to connect my LilyGo.

Software setup ¶

For the LilyGO T-CAN485 ESP board with esphome-nibe combination I chose, I combined the default esphome config template with the LilyGO example (github.com) config of esphome-nibe. This connects to the heatpump via modbus and sets up a UDP daemon for interfacing, which can be read out via nibe_heatpump (home-assistant.io) integration on Home Assistant.

Reading out diagnostics ¶

Determining diagnostics ¶

Once you have a hardware setup for modbus, you can read out certain ‘coils’ which are diagnostics parameters, see e.g. this list of parameters (github.com) (F1155/F1255 (github.com) specifics). In my case many of the >100 parameters were not active. You can plug in a USB stick as well which prints a log file and allows you to

Translation tables ¶

Translation table for eb100_ep14_pca_base_relays_43514:

• 3: off
• 7: heat
• 15: hot water
• ??: cooling

Translation table for eb100_ep14_pca_base_relays_43514:

Calibration of power usage ¶

There are two sensors giving power:

1. compr_in_power_43141: heat pump compressor power
2. int_el_add_power_43084: resistive heater

Using a Riemann integration sensor in Home Assistant gives me energy use (ensure to use left integration, although trapezoidal should work better it doesn’t).

Automating / optimizing ¶

There’s a few ways to optimize a heatpump

1. Heating curves - determining heating circuit temperature depending on outside temperature
2. Timing - optimize consumption by price / CO2 intensity / PV production
3. Calibrating heating circuit (‘Waterzijdig inregelen’) - ensuring optimal heat transfer of the heating circuit

Optimizing curves ¶

TODO

By electricity price / CO2 intensity ¶

Rationale: consume depending on electricity price

1. Use the built-in smart price adaptation (nibe.eu)
2. Use hard-coded schedule based on average electricity prices over the day
3. Use dynamic control via e.g. Home Assistant

By PV production ¶

Rationale: consume depending on local electricity production. This is close to the above, except less at night and more during the day.

Open items ¶

1. What is the difference between HW top and HW load?

Sources ¶

1. NIBE L/W warmtepomp optimalisatie (tweakers.net)
2. Haal meer uit je NIBE warmtepomp met nibepi (tweakers.net)
3. COP berekening voor Nibe warmtepompen (tweakers.net) – NB this is not really COP, but COP scaled from specs based on working point.