Temperature targets: Most CPUs operate safely up to 95-100°C, but optimal performance occurs below 80°C. Idle temperatures should be 30-50°C, while gaming/workload temperatures of 60-75°C indicate good cooling. Temperatures consistently above 85°C suggest inadequate cooling.

Tower Air Coolers: Use large heatsinks with heat pipes and fans to dissipate heat. Range from budget $20 options to premium $100+ models. Offer excellent price-to-performance, reliability, and low maintenance. Require significant case height clearance (150-170mm typical).

All-in-One (AIO) Liquid Coolers: Closed-loop systems with CPU block, radiator, and pump. Available in 120mm, 240mm, 280mm, and 360mm radiator sizes. Provide better cooling for high-end CPUs and improved aesthetics. Cost more than equivalent air cooling and have potential pump failure risk.

Low-Profile Coolers: Compact designs under 70mm height for small form factor cases. Include downdraft coolers, slim towers, and specialized SFF designs. Limited cooling capacity but essential for ITX builds and HTPCs.

TDP basics: TDP represents heat output under typical workloads, measured in watts. Intel i5 processors typically have 65-125W TDP, while i7/i9 can reach 125-250W. AMD Ryzen 5 processors range from 65-105W, with Ryzen 7/9 reaching 105-170W. However, actual power consumption can exceed TDP significantly during boost periods.

Single Tower Coolers ($20-60): Feature one heatsink tower with 3-4 heat pipes. Good for mainstream CPUs up to 150W TDP. Examples include Cooler Master Hyper 212, be quiet! Pure Rock. Offer excellent value but may struggle with high-end processors.

Dual Tower Coolers ($60-100): Use two heatsink towers with 6+ heat pipes and dual fans. Handle high-end CPUs up to 200W+ TDP. Examples include Noctua NH-D15, be quiet! Dark Rock Pro 4. Provide near-liquid cooling performance with better reliability.

Low-Profile Coolers ($25-80): Under 70mm height for compact cases. Include downdraft designs like Noctua NH-L9 series or slim towers like Scythe Big Shuriken. Limited to 95W TDP typically but essential for SFF builds.

120mm AIOs ($60-100): Single 120mm radiator, compact size. Performance often matches good air coolers but at higher cost. Best for cases with severe height restrictions but AIO mounting options.

240mm AIOs ($80-150): Dual 120mm radiator, excellent performance. Sweet spot for liquid cooling - handles high-end CPUs while fitting most cases. Popular examples include Corsair H100i, NZXT Kraken X53.

280-360mm AIOs ($120-250): Maximum cooling performance for extreme processors. 280mm uses dual 140mm fans (quieter), 360mm uses triple 120mm fans (maximum cooling). Required for CPUs like i9-13900K, Ryzen 9 7950X under sustained loads.

Custom Loops ($300+): For enthusiasts only. Offer maximum cooling performance and customization but require extensive knowledge, maintenance, and significant investment. Consider only for extreme overclocking or aesthetic builds.

Fan considerations: 140mm fans typically run quieter than 120mm fans at equivalent cooling performance. PWM (4-pin) fans offer better speed control than 3-pin fans. Quality fans like Noctua, be quiet!, or Arctic last longer and run quieter than generic options.

Budget Builds ($20-40): Stick with quality stock coolers for low-TDP CPUs, or upgrade to basic tower coolers like Cooler Master Hyper 212 or Arctic Freezer 34. Sufficient for mainstream CPUs without overclocking.

Mid-Range Builds ($40-80): Premium tower coolers like Noctua NH-U14S, be quiet! Dark Rock 4, or basic 240mm AIOs. Handle most CPUs including moderate overclocking. Best price-to-performance ratio.

High-End Builds ($80-150): Dual-tower monsters like NH-D15, or quality 240-280mm AIOs. Required for high-TDP CPUs like i7/i9, Ryzen 7/9. Enable significant overclocking headroom.

Enthusiast Builds ($150+): Premium 280-360mm AIOs or custom loops. For extreme processors, heavy overclocking, or aesthetic showcases. Diminishing returns beyond this price point for most users.

Intel 12th-14th Gen (LGA1700): i3/i5 models work well with $40-70 tower coolers. i7 processors benefit from $70+ coolers or 240mm AIOs. i9 models require premium cooling - dual-tower air coolers or 280mm+ AIOs essential for sustained performance.

AMD Ryzen 5000-7000 Series (AM4/AM5): Ryzen 5 processors pair well with $50-80 tower coolers. Ryzen 7 models need $70+ cooling or 240mm AIOs. Ryzen 9 processors demand premium solutions - high-end air cooling or 280-360mm liquid cooling for optimal boost clocks.

Air Cooler Installation: Typically involves mounting a backplate, applying thermal paste, and securing the cooler with clips or screws. Most installations take 15-30 minutes. Large coolers can be heavy and awkward but rarely require case disassembly.

AIO Installation: Requires mounting the CPU block, routing tubes, and installing the radiator with fans. Takes 30-60 minutes typically. May require case disassembly for radiator mounting and careful tube routing to avoid kinks.

Air Cooler Maintenance: Dust cleaning every 6-12 months using compressed air. Thermal paste replacement every 3-5 years. Fan replacement if bearings fail (5-10 years typical). Total lifespan often exceeds 10 years with proper care.

AIO Maintenance: Radiator dust cleaning every 3-6 months due to tighter fin spacing. No user-serviceable parts - entire unit replacement when pump fails (typically 3-7 years). Some units experience gradual coolant evaporation affecting performance.