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Nibe Heatpump Home Automation - WIP

I have an F1255 Nibe heatpump in my home which I’d like to read out and possibly automate. In this blog post I document my approach.

Goal

  1. Show live performance of the heatpump (e.g. COP) during both heating and cooling
  2. Optimize consumption to either low electricity price (via epexspot) or low carbon intensity (via co2signal)
  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) . Full options are:

  1. Raspberry Pi using nibepi (github.com) OR using nibe (github.com) and nibe-mqtt (github.com) libraries
  2. ESP using esphome-nibe (github.com)

Raspberri Pi with Modbus

Hardware (total: 52 EUR):

Arduino/ESP32 with Modbus (preferred)

Hardware (total: 17-36 EUR):

OR a combined board:

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 them.

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) .

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:

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: internal (hot water?) 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). Whether this fully works I don’t know because I have a gap of ~8kWh/day of unaccounted energy usage (~320W average load)

Test Jan 11, 2024

  1. Energy use: 44.3kWh
  2. From grid: 41.8kWh
  3. To grid: 0.0kWh
  4. From solar: 2.5kWh Total: 41.8-0+2.5 = 44.3

time first_value


2024-01-10T23:00:02Z -8364596400 time last_value


2024-01-11T22:59:02Z -8214195600

(8364596400J-8214195600J)/3600/1000 = 41.778 kWh

Automating / optimizing

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.

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.

#ESP8266 #Heating #Home-Improvement #Linux #Server #Smarthome #Unix