CHPC: Cheap Heat Pump Controller
The CHPC a minimal cost Heat Pump (HP) controller, which can be used as provided, or can be adopted to nearly all use cases due to open source nature.
Works from ground heat collectors (loops) to radiant in-floor heating system.
Driving:
Temperature sensors installed:
Controlled via both RS-485 and 16x2 display with buttons.
Usage. | Brief description. | Application examples | Available protections |
---|---|---|---|
1. Thermostat. | Precision thermostat. Simple and cheap. Only one relay and one temperature sensor required. |
Room heat control. A chicken coop climate control. Distillation column. Else. | N/A |
2. Heat pump (HP) control. | Controller drives HP system components: compressor, Cold and Hot side Circulating Pumps (CP). Protect system from an overload, overheat and freezing up. Drives EEV to optimize running conditions. | DIY heat pump system. Repair module for commercial system. Water heater, house heating systems and same applications. | Compressor: cold start or overheat. Discharge and suction lines protection. Short-term power loss. Anti-freeze. Power overload protection. |
3. EEV controller. | Only drives EEV, no relays. Require two T sensors. | Upgrade your system from capillary tube to EEV. | Protects from liquid at suction line by design. |
For more information about Heap Pumps look at Wikipedia about HP
None: Target temperature uploaded to board with firmware and not changed anymore. System used as an fixed thermostat. You can change target temperature with firmware re-upload.
0.96 OLED or 1602 LCD screen + buttons: Simple, local screen controlled system.
Remote computer terminal over RS-485 line. Target temperature and running conditions under remote control. A user can get stats from all T sensors. Up to 1.2 kilometer line.*
Remote automated control/stats via RS-485. Firmware was written with python scripting in mind (and real scripts at the prototype 485 network).
Both screen + buttons and RS-485. Combination allowed.
* RS-485 specification. The hardware test succeeded on 400 meters line.
Example: day/night setpoint control and data visualization with JSON communication way.
Only one Relay: drive an electric heater (any)
5 Relays, drives all you need:
These abbreviations used in the interface during sensors installation procedure
Abbr. | Full name | Required for |
---|---|---|
Tae | after evaporator | EEV Anti-liquid protection at suction line |
Tbe | before evaporator | EEV |
Ttarget | target | Thermostat Thermostat+EEV |
Tsump | sump | Automatic Compressor Heater Compressor overheat protection |
Tci | cold in | Antifreeze protection |
Tco | cold out | Antifreeze protection |
Thi | hot in | Hot CP automatic control |
Tho | hot out | Overheat protection |
Tbc | before condenser | Discharge overheat protection |
Tac | after condenser | |
Touter | outer (outdoor) | |
Ts1 | additional sensor1 | |
Ts2 | additional sensor2 |
PCB v1.1
This is prototype 2 (PCB v1.0). 1602 is the best choice.
EEV development started here, PCB v1.0.
Prototype 1. Say v0.0. History ) But worked well for a 2018-19 season.
gonzho АТ web.de (c) 2018-2019
If you have any comments or questions, please do not hesitate to contact me.