Marcin at 21:53, 26 December 2025

2025-12-26T21:53:32Z

Marcin: Created page with "= Open Heat Pump Module v1.0 = This page documents an open-hardware heat pump module built from off-the-shelf, serviceable, replaceable HVAC parts. The design is a reversible 2-ton (≈24,000 BTU/h) R-410A heat pump that can be integrated into air-to-water or water-loop hydraulic systems. == Goal == Create a modular, serviceable, repairable heat pump core using standardized refrigeration components that any trained technician can maintain without proprietary..."

2025-12-26T21:51:30Z

Created page with "= Open Heat Pump Module v1.0 = This page documents an open-hardware heat pump module built from **off-the-shelf, serviceable, replaceable HVAC parts**. The design is a **reversible 2-ton (≈24,000 BTU/h) R-410A heat pump** that can be integrated into air-to-water or water-loop hydraulic systems. == Goal == Create a modular, serviceable, repairable heat pump core using standardized refrigeration components that any trained technician can maintain without proprietary..."

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= Open Heat Pump Module v1.0 =

This page documents an open-hardware heat pump module built from **off-the-shelf, serviceable, replaceable HVAC parts**.
The design is a **reversible 2-ton (≈24,000 BTU/h) R-410A heat pump** that can be integrated into air-to-water or water-loop hydraulic systems.

== Goal ==
Create a modular, serviceable, repairable heat pump core using standardized refrigeration components that any trained technician can maintain without proprietary parts or black-box controllers.

== System Overview ==
Each module consists of:
* Refrigeration compressor (≈2-ton, R-410A)
* Reversing valve (4-way)
* Brazed plate heat exchanger (refrigerant to water)
* Expansion device (catalog TXV or EEV)
* Filter/drier, accumulator, service valves
* Controls (temperature sensors, relays/PLC)

Four modules in parallel yield ~96,000 BTU/h total capacity.

== Bill of Materials (per 2-ton module) ==

=== Core Refrigeration Components ===

* **Compressor (2-ton R-410A scroll)**
* **:contentReference[oaicite:0]{index=0}** – widely stocked OEM scroll compressor, 208/230 V.
* **:contentReference[oaicite:1]{index=1}** – lower-cost alternative option.
* **:contentReference[oaicite:2]{index=2}** – budget surplus compressor option.
* **:contentReference[oaicite:3]{index=3}** – cost-competitive eBay option.

* **Reversing Valve (4-way)**
* **:contentReference[oaicite:4]{index=4}** – standard 4-way valve for heat pump duty.
* **:contentReference[oaicite:5]{index=5}** – budget valve option.
* **:contentReference[oaicite:6]{index=6}** – alternative 2-ton reversing valve.
* **:contentReference[oaicite:7]{index=7}** – low-cost generic reversing valve.

=== Heat Exchanger (Refrigerant-to-Water / Plate HX) ===

The refrigerant-to-water heat exchanger is a key part that replaces an air-side indoor coil and lets you extract or reject heat to a water loop.

* **Bell & Gossett brazed plate heat exchangers:**
* https://www.nationalpumpsupply.com/bell-gossett-brazed-plate-heat-exchangers/ – a family of quality brazed plate HXs in a range of sizes suitable for 2-ton service (e.g., BP400-20, BP400-30MT, BP400-40). :contentReference[oaicite:8]{index=8}

* Other brazed plate suppliers (R410A capable):
* Alibaba R410A brazed plate HX listings – industrial/contractor supply. :contentReference[oaicite:9]{index=9}
* Alfa Laval / SWEP BPHE catalogs – high-performance brazed plates. :contentReference[oaicite:10]{index=10}

*Note:* Plate HXs must be rated for R-410A pressures (≈450-650+ psi) and water side pressures typical of hydronic systems. :contentReference[oaicite:11]{index=11}

=== Other Refrigeration Parts (Standard HVAC) ===

* Expansion Device (TXV or Electronic Expansion Valve) sized for 2–3 ton R-410A duty (from HVAC wholesaler).
* R-410A bi-flow filter/drier.
* Suction accumulator.
* Service valves and access ports.
* Sight glass (optional) for service diagnostics.

These parts are commodity HVAC parts available from local wholesalers.

=== Hydronic Components ===

* Water circulator pump (≈3–8 GPM range depending on module quantity).
* PEX/Tubing, manifolds, IBC tote manifold headers.
* Hydronic buffer tank(s) or thermal battery.
* Load side heat exchangers e.g., fin-coil units or radiant manifolds.

== Refrigerant Circuit (Simplified) ==

1. Compressor discharge → reversing valve.
2. Reversing valve switches flow between:
* Outdoor air coil (evaporator in heat mode)
* Brazed plate water coil (condenser in heat mode).
3. Liquid line filter/drier and expansion device (TXV/EEV).
4. Evaporator/plate HX → suction accumulator → compressor suction.

*Ensure correct bi-flow filter/drier and proper check valves for bi-directional flow in heat pump mode.*

== Line Sizes and Connections ==

* Suction: ~3/4″ ODF or flare (common for 2-ton compressors). :contentReference[oaicite:12]{index=12}
* Liquid: ~1/2″ ODF or flare. :contentReference[oaicite:13]{index=13}
* Brazed plate HXs: typical 1/2″ to 3/4″ ports depending on model.

Match hose/barb or flare adapters accordingly.

== Controls ==

* Temperature sensors on water inlet/outlet.
* Refrigerant pressure sensors (optional).
* Relays/solid-state drivers for:
* Compressor contactor.
* Reversing valve solenoid.
* Outdoor fan motor.
* Water circulator pump.
* Open controller (PLC/ESP32/industrial controller) with basic logic for:
* Heat/cool mode.
* Defrost (if outdoor coil used as evaporator).
* High/low pressure protection.

== Notes ==

* This design uses **standard R-410A refrigerant**, which is common in residential HVAC equipment. :contentReference[oaicite:14]{index=14}
* All pressurized refrigeration work must be performed by a certified HVAC technician with proper tools and leak testing.
* Brazed plate heat exchangers for HVAC duty must be rated for R-410A service and hydronic water pressures. :contentReference[oaicite:15]{index=15}
* This open architecture decouples the **heat pump core** from proprietary OEM boards, enabling replacement of compressors, valves, and heat exchangers with catalog parts.

== Open Hardware Intent ==

This repository’s purpose is to define a **modular, repairable heat pump building block** that:

* Uses widely available components.
* Can be maintained without proprietary spares.
* Serves as the basis for higher-level systems (thermal batteries, PV-driven heating, open water heater modules).
* Allows swarm innovation on controls, hydronics, and integration without vendor lock-in.

Open Source Heat Pump BOM - Revision history

Marcin at 21:53, 26 December 2025