#Cheap Heat Pump Controller (CHPC)
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. --------------------------------------------------------------------
###Applications: ###1. Thermostat. _Brief_: Precision thermostat. Simple and cheap. Only 1 relay and 1 temperature sensor required. _Application examples:_ Room heat control. Chicken coop climate control. Distillation column. Else. ###2. Heat pump (HP) controller. _Brief_: Heat pump controler. Controller drives HP system components: compressor, Cold and Hot side Circulating Pumps (CP). Protects system from overload, overheat and freezing up. Drives EEV to optimize HP running conditions. _Application examples:_ DIY heat pump system. Repair module for commercial system. Water heater, house heating systems and same. _Available protections_: Compressor: cold start or overheat. Discharge and suction lines protection. Short-term power loss. Anti-freeze. Power overload protection. Others. ###3. EEV controller. _Brief_: EEV driver, no relays. Requires 2 T sensors. _Application examples:_ Upgrade your system from capilary tube to EEV. _Available protections_: Protects from liquid at suction line by design. For more information about Heap Pumps look at [Wikipedia about HP](https://en.wikipedia.org/wiki/Heat_pump)
###Features: - Up to 13 T sensors (more info: github page), - 5 relays (Compressor, Hot CP or Air Fun, Cold CP or Air Fun, Sump Heater, 4-way valve), - 4 inputs, - 5/6 pin EEV connection, - 1602 display support, - RS485 or Serial(UART 5V) support, - Automatically turns on/of system when heating required, - Takes care of system components health.
###Control interfaces: None: Target temperature uploaded to board with firmware and cannot be changed. System used as fixed thermostat. Target temperature can be changed later with firmware re-upload. 0.96 OLED or 1602 LCD screen + buttons: Simple, local screen controlled system. Remote control is not possible. Remote computer terminal over RS-485 line. Target temperature and running conditions under remote control. 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 prototype 485 network). Both screen+buttons and RS-485. Combination allowed. \* RS-485 specification. Hardware test succeeded on 400 meters line.
###Relays: ###"Thermostat": Only 1 Relay: drives electric heater (any) ###Heat Pump. Capillary tube, TXV, EEV: 5 Relays, drives all you need: * Compressor (can be used as external relay driver for High Power systems) * Cold Circulating Pump (CP) * Hot CP * Sump Heater (optional, recommended for outdoor HP installations) * 4-way Valve (support coming up: autumn 2019) ###Temperature sensors: * Up to 13 temperature sensors can be connected to CHPC to control all processes that you want. * Only 1 sensor needed for "Thermostat" or "Heat Pump capillary/TXV" * 3 sensors needed for "HP with EEV" (absolute minimum scheme)
* See [https://github.com/gonzho000/chpc](https://github.com/gonzho000/chpc) for more details and firmware

Found 1 3D-models for “cappilary” across many websites

Cheap Heat Pump Controller