Under-dash heaters and compact A/C units add climate control to vehicles lacking factory systems. Below is a quick comparison of five relevant under-dash heater and heat/cool combo kits selected for universal fit, power source, and installation options.
| Product | Type | Power | Key Feature |
|---|---|---|---|
| Kit Universal A/C Under Dash Heat & Cool 404-000 DBSL | Heat & A/C Kit | 12V / Compressor | 12,700 BTU capacity, condenser + compressor included |
| Saihisday 12V Car Truck Under Dash | Evaporator / Heat & Cool | 12V, 7.6A | Higher cooling BTU stated, electrical thermostat |
| Saihisday BEU-404-100 Evaporator Assembly Kit | Evaporator / Heat & Cool | 12V, 7.6A | 22-pass evaporator, 4-way air, up to 600 CFM max airflow |
| Universal 12V Under Dash Air Conditioner With Heat Strip | Inverter A/C With Heat | 12V, inverter compressor | 20cc inverter/scroll compressor, low-noise operation |
| Under Dash Heater 12V 4 Ports (DNYSYSJ) | Auxiliary Heater | Coolant-powered | 4-port warm air outlets, uses engine coolant for heat |
Content Navigation
- Kit Universal A/C Under Dash Heat & Cool 404-000 DBSL
- Saihisday 12V Car Truck Under Dash, A/C Evaporator Assembly
- Saihisday BEU-404-100 Evaporator Assembly Kit 2 Vents
- Universal 12V Under Dash Air Conditioner With Heat Strip
- Under Dash Heater 12V 4 Ports Universal Auxiliary Heater
- Buying Guide: How To Choose An Under Dash Heater Or A/C Unit
Kit Universal A/C Under Dash Heat & Cool 404-000 DBSL
This kit is a full under-dash HVAC solution that includes an evaporator, compressor, and condenser components for a complete installation. The listed 12,700 BTU capacity and 359 CFM airflow indicate a system intended for significant cooling performance for enclosed cab spaces.
- Evaporator: E-404-000 DBSL H/C, 32 pass, 4-way aluminum coil, expansion valve, 1.5 ton thermostat, rotative 3-speed blower switch, 4 black star louvers.
- Compressor: Sanden-style C5H142A12V with 12V coil and pulley options; designed for automotive belt drive.
- Condenser: Parallel flow micro-tube CPF142018, aluminum rails; compact profile for under-hood mounting.
- Included mounting bracket, drain hose, T fittings, and 10′ flex duct.
Because this product ships as a multi-component kit, expect a requirement for mechanical fitment of the compressor and condenser along with refrigerant charging. The package is suited to users planning a full aftermarket A/C install in trucks, vans, or classic cars.
Saihisday 12V Car Truck Under Dash, A/C Evaporator Assembly
This under-dash unit focuses on the evaporator/air delivery side and targets vehicles without factory A/C. The product lists both heating and cooling capacities and emphasizes a 12V electrical thermostat control.
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- Power: 12V, 7.6A operation suitable for typical vehicle 12V electrical systems.
- Heating/Cooling: Heating capacity ~14,360 BTU (3619 kcal/h), cooling capacity ~16,297 BTU (4107 kcal/h) per listing.
- Design: Universal evaporator intended for retrofit installation with multiple port options for ducting and mounting.
The unit is positioned as a retrofit evaporator/air-delivery assembly; integration with a compressor and condenser (if cooling is desired) will be necessary unless used solely as a heater with a heat source or electric strip. The electrical thermostat allows user temperature control without complex vacuum or HVAC controls.
Saihisday BEU-404-100 Evaporator Assembly Kit 2 Vents
The BEU-404-100 is an evaporator-based kit offering both heating and cooling functions with a higher airflow orientation. It lists a multi-pass evaporator section and a claimed max air volume up to 600 CFM for strong cabin circulation.
- Evaporator & Heater: 22-pass 4-way AL evaporator for cooling; 6-pass 2-way AL heating core.
- Electrical: 12V, 7.6A supply with electronic thermostat and 3-speed airflow control.
- Performance: Cooling ~4107 kcal/h, heating ~3619 kcal/h; multi-speed blower for varied airflow needs.
This kit suits retrofit projects where the evaporator assembly, blowers, and controls are the main deliverables. It requires connection to a refrigerant circuit for cooling or to a heat source for heating, depending on installation choices.
Universal 12V Under Dash Air Conditioner With Heat Strip
This compact underdash A/C claims inverter compressor technology and integrated heat strip for combined cooling and electric heating. The listing focuses on energy-saving operation and low noise for passenger comfort.
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- Inverter Cooling: Frequency-adjusting compressor for improved energy efficiency.
- Compressor: Professional-grade 20cc scroll compressor referenced in features for rapid temperature regulation.
- Noise: Marketing mentions operation below 50 dB for quieter cabin environments.
- Heat Strip: Electric heating element option for warmth when engine heat is unavailable.
This unit is targeted at users seeking a self-contained electrical HVAC approach where an inverter compressor and electric heat provide all-season capability without routing engine coolant or installing belt-driven compressors. Electrical supply capacity and vehicle alternator capability should be checked before purchase.
Under Dash Heater 12V 4 Ports Universal Auxiliary Heater
This auxiliary heater uses engine coolant to provide cabin heat and is marketed for a wide range of vehicles including trucks, minivans, and construction equipment. It emphasizes low energy consumption by leveraging waste engine heat.
- Operation: Uses engine coolant and a powerful blower motor to deliver warm air via four outlet ports.
- Design: Mounting brackets and speed control switch included for under-dash installation.
- Heating Core: Copper pipe heating core for efficient heat transfer and rapid warm-up.
Because this heater taps into engine coolant, it integrates directly with the vehicle’s cooling system. It is suited to users who want additional cabin heat or faster defrost capability without an electrical heating element or refrigerant circuit.
Buying Guide: How To Choose An Under Dash Heater Or A/C Unit
Choosing the right under-dash unit requires matching the product type to your vehicle, electrical system, and installation willingness. Below are the key considerations to guide selection.
Type Of System
- Coolant-Based Heater: Uses engine heat; best for supplemental heating and defrosting. Lower electrical draw but requires plumbing to coolant lines.
- Electric Heat Strip: Self-contained electric heating; useful when engine heat is unavailable but increases electrical load on alternator/battery.
- Evaporator Only: Provides blower and air distribution; requires external compressor and condenser for cooling operation.
- Full HVAC Kit: Contains evaporator, compressor, and condenser; suitable for full retrofit A/C installations but requires mechanical mounting and refrigerant handling.
Power And Electrical Considerations
- 12V Supply: Most under-dash units run on 12V; confirm amp draw (e.g., 7.6A listings) and ensure vehicle wiring and fuse capacity match.
- Compressor Type: Belt-driven compressors require mechanical mounting; inverter and scroll compressors require robust electrical supply and may need DC-to-AC inverters or dedicated controllers.
- Alternator Capacity: High-draw electric compressors or heaters demand sufficient alternator output to avoid battery drain.
Cooling And Heating Capacity
- BTU / kcal Ratings: Higher BTU indicates stronger cooling/heating potential; match capacity to cabin volume. Universal kits list BTU or kcal—use these to compare performance.
- Airflow (CFM): Look for blower airflow ratings (e.g., 300–600 CFM) which affect how quickly the cabin reaches set temperature.
Installation Complexity
- Plug-and-Play Evaporators: Some evaporator assemblies are simpler installs if used only for heating or attached to an existing refrigerant system.
- Full Compressor Kits: Require mechanical installation of compressor and condenser, belt or mounting considerations, and refrigerant charging by a qualified technician in many jurisdictions.
- Coolant Hookup: Coolant-based units need routing heater hoses and may require draining and system bleeding—consider a professional if unfamiliar.
Fitment And Space
- Under-Dash Clearance: Measure available space under the dash or seat. Many units include compact condensers, but compressor mounting needs engine-bay room.
- Ducting: Verify included ducting length and outlet configuration to reach desired vents and defroster locations.
Noise And Comfort
- Blower Noise: Product literature may list dB; quieter units improve long-distance comfort.
- Air Distribution: Four-way louvers and multiple outlet ports improve directional control of airflow for passenger comfort.
Durability And Materials
- Coil Material: Aluminum coils resist corrosion and are common; titanium coatings are noted in some listings for increased corrosion resistance in marine or salty environments.
- Compressor Quality: Look for proven compressor designs (e.g., Sanden-style) if integrating a belt-driven compressor; inverter/scroll units have different maintenance profiles.
Regulatory And Safety
- Refrigerant Handling: Cooling kits that require refrigerant charging should be serviced by qualified technicians and comply with local laws for refrigerant use and recovery.
- Electrical Safety: Confirm proper fusing, wiring gauge, and connections. High amp draws without proper wiring can cause overheating.
Comparison Perspectives
- Performance vs. Simplicity: Full kits (compressor + condenser + evaporator) deliver the most complete cooling but are complex to install. Evaporator-only or coolant heaters are simpler but may need other systems to deliver full A/C capability.
- Electrical Load vs. Engine Integration: Electric-inverter solutions remove the need for belt mounting but demand electrical capacity. Coolant-based heaters use engine waste heat and have minimal electrical impact.
- Cost of Installation vs. Features: Consider the professional labor and potential modifications required for compressor mounting and refrigerant charging when evaluating overall project cost.
Use the considerations above to align the selected unit with your vehicle type, desired functionality (heating only, cooling, or both), and your capacity for installation. For refrigeration additions, plan for professional refrigerant service and mechanical mounting where required.
Tips for Getting the Best HVAC Prices
- Prioritize Quality Over Cost
The most critical factor in any HVAC project is the quality of the installation. Don’t compromise on contractor expertise just to save money. - Check for Rebates
Always research current rebates and incentives — they can significantly reduce your overall cost. - Compare Multiple Quotes
Request at least three estimates before making your choice. You can click here to get three free quotes from local professionals. These quotes include available rebates and tax credits and automatically exclude unqualified contractors. - Negotiate Smartly
Once you've chosen a contractor, use the proven strategies from our guide — How Homeowners Can Negotiate with HVAC Dealers — to get the best possible final price.