12-24VDC 75W 252 BTU BD25HC R134A Compressor Small Condensing Unit For 100L Refrigerator Freezer Cooler Air Cooling With Temperature Controller DIY KIT

Specifications:

• Product: Refrigeration Condensing Unit
• Model: BD25HC

      Digital Thermostat Controller:

• Voltage range: DC 12-24V
• Operating current: 0.1A
• Door Lamp Function: Door lamp voltage follows input voltage
• Temperature probe accuracy: ±1℃
• Operating ambient temperature: -10℃～60℃.
• Dimensions(L*W*H)
• Fan: 120*120*25mm
• Condensing Unit:330*180*165mm

      Compressor:

• Model: BD25HOperating voltage: 12/24V DC
• Maximum input voltage for DC 12V:17V
• Maximum input voltage for DC 24V:31.5V
• Working Back Pressure: Low Back Pressure (L.B.P)
• Cooling status: natural cooling / air-cooled
• Throttling device: capillary tube
• Motor type: BLDC
• Ambient temperature: 0～43℃
• Evaporating temperature: -35～-10℃
• Operating voltage range: 9.6～17/21.3～31.5V
• Max. exhaust pressure: 1.86 MPa(abs)
• Max. condensing temperature: 65℃
• Max. winding temperature: 130℃
• Max. case temperature: 95℃
• Max. exhaust temperature: 120℃
• Starting performance : 12/24V [0.5/0.5MPa(abs)
• Minimum case pressure: 35 bar
• Oil type: Ester oil
• Oil filling volume: 150ml±10ml
• Diameter of suction pipe (inner diameter): Φ6.2±0.1 mm
• Exhaust pipe diameter (inner diameter): Φ5.0±0.1 mm
• Process pipe diameter (inner diameter): Φ6.2±0.1 mm
• Compressor noise : ≤40dB(A)\
• Vibration: 0.6m/s²。
• Working volume:2.5cm³

Cooling Capacity:

• RPM is 2000, cooling capacity is 45W , 38.7 Kcal/h ,153.5 btu/h,Efficiency COP is 1.25 w/w,electric current is 2.9/1.4，input Power is 36W
• RPM is 2500, cooling capacity is 55W , 47.3 Kcal/h ,187.7 btu/h,Efficiency COP is 1.25 w/w,electric current is 3.5/1.7,input Power is 44W
• RPM is 3000, cooling capacity is 64W , 55 Kcal/h ,218.4 btu/h,Efficiency COP is 1.25 w/w,electric current is 4.1/2.0, input Power is 51W
• RPM is 3500, cooling capacity is 74W , 63.6 Kcal/h ,252.5 btu/h,Efficiency COP is 1.25 w/w,electric current is 4.9/2.4, input Power is 59W

Applications:

• For refrigerators Within 100 litres, freezers, fridges, water coolers, ice machines, etc and prototyping projects.

Package Includes:

• 1 x 12-24VDC 75W BD25HC R134A Compressor Small Condensing Unit With Temperature Controller DIY KIT

Features:

• Adapts to dual voltage, i.e. DC 12V and 24V power input systems
• Cooling Capacity of 252 BTU (74W)
• Efficient Cooling Performance with 1.2COP
• Working volume up to 2.5cm³
• Suits for prototyping projects, small size refrigerators and freezers within 100L capacity
• Comes with a temperature control panel and power cord with an  alligator clip
  Versatile Application and Compatibility
• Durable and User-Friendly Design

Frequently Asked Questions (FAQ)

• Does this kit come pre-filled with R134A gas?
  No. Due to shipping regulations and the need for you to connect custom tubing, the unit is shipped with a holding charge or empty. You must vacuum and fill it after assembly.
• Can I run this directly from a solar panel?
  Not directly. You need a battery buffer (12V or 24V) to handle the startup current surge. Connect the solar controller to the battery, and the battery to this compressor.
• What is the maximum size fridge this can cool?
  For a well-insulated box (50mm PU foam), it can handle up to 100 Liters for fridge temperatures (4°C) or 40-50 Liters for freezer temperatures (-18°C).
• Is the temperature controller included?
  Yes, a digital thermostat with a temperature probe is included and pre-wired to the compressor driver.
• How much power does it consume?
  It varies by load, but typically between 40 Watts and 75 Watts. This is significantly more efficient than a Peltier cooler which often draws 70W+ for much less cooling.
• Can I use this to make an air conditioner?
  Technically yes, for a very small space (like a pet crate or a helmet cooler), but 252 BTU is too small for cooling a room or a car cabin.
• What kind of evaporator do I need?
  You can use a roll-bond evaporator plate, a copper coil, or a fin-and-tube heat exchanger, depending on your project.
• Do I need to solder the copper pipes?
  Yes, or use high-quality compression fittings. However, brazing/soldering is recommended for a leak-proof refrigeration seal.
• Can I use R600a gas instead of R134A?
  No. The BD25HC is designed specifically for R134A oil and pressure ratios. Using other gases can damage the compressor.
• What battery do you recommend?
  A 12V Deep Cycle or LiFePO4 battery with at least 20Ah to 40Ah capacity is recommended for reliable daily operation.
• Does the compressor have a low-voltage cutoff?
  Yes, the controller board has built-in battery protection to prevent deep discharge of your lead-acid or lithium battery.
• Can I replace the digital controller with an Arduino?
  Yes. You can bypass the stock controller and use a relay or MOSFET (rated for the signal current) to trigger the compressor ON/OFF via the control pins.
• How loud is the unit?
  It is very quiet, typically <40dB, similar to a high-quality home refrigerator.
• What is the filter drier for?
  It removes moisture and contaminants from the refrigerant gas. It is a critical component that is already installed on the high side for you.
• Can I mount this unit upside down?
  No. Rotary compressors must be mounted horizontally (upright) to ensure proper oil lubrication.
• Does it vibrate a lot?
  The compressor is mounted on rubber vibration isolators, so vibration is minimal and won't damage your enclosure.
• What is the maximum pressure this system reaches?
  The high side (condenser) can reach up to 200-250 PSI depending on ambient temperature. Always wear safety glasses!
• Why is the "Condenser" fan blowing hot air?
  That is normal! It is removing heat from the refrigerant gas. Ensure the fan has good airflow and isn't blocked.
• Can I extend the wires for the display?
  Yes, the temperature probe and display wires can be extended if you want to mount the controls far from the compressor.
• Do you sell the evaporator and capillary tube?
  We currently sell this as a condensing unit kit. Please check our "Cross Sell" section or consult a local refrigeration spares shop for the specific tubing length you need.