Flow, temperature, energy measurement and PWM pump control
- Measure temperature IN and OUT (DeltaT) for floor heating and boiler
- Measure water flow
- Calculate Energy: Flow * DeltaT * 4.18
- Control the floor heating pump by PWM, based on DeltaT
- Report flow, temperature, energy and pump speed to Domoticz
- Control pump On/Off from Domoticz
- A small box for local read-out with a LCD 1602
- Switched back-light for the LCD
- Water consumption flow/temperature measurement
- Boiler-load energy measurement
- Boiler-unload energy measurement for sanitair water
- Boiler-unload energy measurement for floor heating
- Floor heating energy consumption
- Floor / Air thermostat
- Temperature-adaptive floor heating pump control
- Automatic / Manual Boiler temperature adjustment (NTC adjustment)
After more then 23 years of operation, it's time to re-think and replace some components of my central heating system.
The modified system will be based on a Producer-Consumer concept. Heat producers and heat consumers with both their optimal pace by decoupling with a boiler-buffer in-between.
In 2014, I modified the Grundfos UPS 25-60-180 floorheating pump's from mechanical 3 speed adjustment to a Z-wave 3 speed remote control capability. While the conventional mechanical adjustment can still be used. See: http://www.domoticz.com/forum/viewtopic.php?f=34&t=5025
During the refurbishment those pumps will be replaced (after 23 years of problem-free operation!) by PWM controlled pumps based on DeltaT and flow measurement will be added, to calculate the effective heat consumption of the 2 distribution units.
Since 2014, I measure with #16 DS18B20 sensors via #4 Z-Wave units, the heater and floor distribution units In/Out temperatures. In 2017, I started to replace them by 2# ESP_Easy units and increased the number of sensors to #28.
A good insight of the real energy need is lacking:
m3 gas * gas energy content * heater brochure efficency
the latter are both disputable (like with cars!).
For that reason I like to calculate the energy production/consumption with:
Flow * DeltaT * 4.18
Further posts will cover:
- Electrical scheme
- Bill of Material
- Building suggestions (1&2)
- RCWL-0516 Microwave Radar modification
- Level shifter modification and PWM discussion
- ESP Tasks
- ESP Rules
- Known Issues
- Incoming fresh water measurement
- Floor thermostat with rotary encoder adjustment
- Boiler thermostat with rotary encoder adjustment
[edit 21-1-19] application update