Liquid Cooling "Wish List" -- compiled by Short Course attendees, December 2005

Since this is a wish list, of course some of these ideas are going to sound impossible. But you never know! (This list has been edited only for clarity.)

• I wish I didn't have to do it!
• Manage hot spots (due to power map) using tunable local heat transfer coefficient or flow variation in cold plate
• One stop shop for all the parts of a system, including non-thermal: fittings, accumulators, reservoirs; industrial and military grade
• Maintenance free complete systems
• Faster fluid temperature response time, dT/dt
• Bubble free systems
• Pumps with built-in redundancy
• Compact, reliable pumps
• Method to minimize bubble size in two-phase flow
• Low cost cold plates
• Corrosion inhibitors suitable for microchannel applications
• Permanent (maintenance free) biocide
• Durable filter for microchannel applications
• Low pressure drop, compact filter
• Self-cleaning filter
• Self-cleaning system (as for ovens)
• Coolants with better thermophysical properties than water
• Method or product to minimize fouling
• Readily available materials compatibility information
• Lightweight materials for fittings and cold plates
• Smaller fittings
• Thinner-walled fittings (to save weight)
• Lower pressure drop quick-disconnect couplers
• Lower friction (I think this means pressure drop) hoses
• Better internal surface coatings for lower pressure drop, corrosion protection, smoother surface, smaller bubbles
• Vibration damping materials in plumbing, fittings, and cold plates
• Improved pump reliability
• Non-cyclic (screw type) pump
• Flexible high-performance heat pipe
• Coolant with lower boiling point, around -55 C
• High-COP thermoelectric coolers
• Modular cold plates that can be assembled like Legos
• Cold plates for multiple processors (adjustable heights)
• Chassis with built-in liquid manifold -- just plug in your hoses
• Cogeneration -- use waste heat from electronics to heat domestic water or air (similar to automotive model) or power a refrigeration (absorption cycle)
• Software to help design liquid cooling systems (plumbing, power map, spreading, heat exchanger and fan)
• Formulate liquid cooling roadmap

Top concerns about implementing liquid cooling, according to CoolingZone Summit Short Course attendees in August 2005:

• leaks

  management resistance

  cost

  field service

  corrosion

  mold growth

  reliability -- many single points of failure

  supply chain -- doesn't have multiple selection of well-tested products

  lack of standards -- part interchangeability, interfacing and  mating parts

  thermal interface -- mating parts, CTE issues

  electrical conductivity of system

  serviceability

  filtration

  ruggedness of heat exchanger

  EE resistance (conductive fluid)

  space

  weight

  portability (weight, size, power consumption)

  design complexity

  coolant limitations (few choices, drawbacks)