Saihisday Under-Dash Universal 12V Evaporator/Heater Core — 4 Vents, 22-Pass Coil (Compact Retrofit)

If you want to retrofit an older car, truck, or custom vehicle with climate control, this compact Saihisday evaporator/heater unit supplies both cooling and heat through four directional vents and a 22-pass coil design. The assembly runs on 12V at 7.6A, pairs with external compressors and condensers, and is built for integration beneath the dash rather than direct bolt-in replacement. It’s sold as the evaporator/heater core only — mounting and refrigerant plumbing are part of the install process.

How much cooling and heating performance does this unit deliver?

The unit provides substantial thermal capacity for a compact under-dash core: roughly 4,107 kcal/h cooling (about 16,297 BTU) and 3,619 kcal/h heating (about 14,360 BTU). Its 22-pass, four-way coil and blower design optimize airflow through the cabin when matched with a suitable condenser and compressor.

• Cooling capacity: 4107 kcal/h (≈16,297 BTU)
• Heating capacity: 3619 kcal/h (≈14,360 BTU)
• Power draw: 12V, 7.6A with electrical thermostat control
• 22-pass coil for increased heat exchange and airflow

What does “universal” mean and will it fit my vehicle?

Universal indicates the core is designed to be adaptable to many dashboards rather than being a model-specific, bolt-in part. It is intended for custom installation projects where the evaporator is mounted under the dash and connected to an aftermarket compressor, condenser, hoses, and controls.

• Not a direct OEM replacement — custom mounting and brackets usually required
• Requires external refrigeration components and professional or skilled DIY installation
• Works best in older vehicles or custom builds that lacked factory A/C
• Electrical thermostat included for temperature regulation, integrates with vehicle 12V system

What do I need to install this evaporator assembly?

Installation requires basic HVAC components and some fabrication: a compatible compressor and condenser, refrigerant lines, expansion valve/orifice, receiver/drier or accumulator, and wall fittings or bulkhead ports through the firewall. Proper evacuation and refrigerant charging must be performed to system specifications.

• Aftermarket compressor and condenser matched to cooling capacity
• Refrigerant lines, fittings, expansion device, and drier/accumulator
• Mounting brackets or custom under-dash support and vent routing
• Tools for evacuation, charging, and leak testing — or professional HVAC service

How does the user interface and airflow work on this unit?

The assembly routes conditioned air through four directional vents allowing targeted distribution across the cabin. Fan speed and temperature are controlled via a 12V electrical thermostat and the blower; airflow patterns depend on ducting and vent orientation chosen during installation.

• Four-way vents allow directional airflow to driver and passengers
• Electrical thermostat provides temperature regulation on 12V systems
• Airflow effectiveness depends on duct layout and vent placement
• Designed for under-dash mounting to keep instrument panel clearance

Who is this for? The Saihisday universal evaporator assembly is aimed at car and truck owners, custom builders, and restoration specialists who want to add factory-style A/C and heating to vehicles without original equipment. It’s ideal for those comfortable planning or overseeing a retrofit — including selecting a matched compressor, condenser, and fittings — or for professional installers seeking a compact, high-capacity under-dash core for custom systems.