LiquidCool Submerged Server Technology (LSST) frequently asked questions
LiquidCool Submerged Server Technology (LSST) employs total liquid immersion cooling, a cost-efficient technology that eliminates fans and substantially reduces the amount of energy needed to cool IT components. Liquid immersion cooling exposes components directly to a dielectric liquid coolant.
LSST coolant has 1400 times more heat capacity than an equal volume of air, making it a far more effective at transporting heat. Using our patented Directed Flow technology to circulate fluid through a sealed server chassis, coolant is constantly flowing through the system, maintaining optimal stability and reducing power-to-cool by 98%. Unlike water, the coolant LSST uses does not carry an electric charge and is completely safe to use with any electronic component. A diagram of coolant flow through the system is shown below:
The system is fanless and there are no moving parts in the chassis. In fact, the only moving parts are central pumps, typically located in a mechanical room. Liquid coolant is pumped through the server chassis, removing heat from all of the components and carrying the heat out of the unit. The warm liquid then flows to a heat exchanger, where the temperature is reduced and the cycle repeats, similar to the central heating system in a home. The “cool” liquid can be as hot as 45°C (113°F), so the heat exchanger typically is a simple fan-coil system.
LSST uses a sealed system, similar to the coolant system in a vehicle. That means you’ll never see the fluid except when performing an upgrade, in which case it can be drained in 90 seconds using a simple tool. Only LSST and its licensees are able to utilize this patented technology. To assure that no coolant will escape from the system, LSST uses a modular design in which each component is individually pressure-tested prior to assembly. LSST systems are also equipped with fluid sensors to detect and isolate the source of any fluid escaping from the system.
Because of the extreme reliability of directed-flow total immersion cooling, LSST servers require a lot less maintenance than conventional server. However, in the event you need to perform component upgrades, the process is simple. LSST server systems are modular in design with all fluid connections made using drip-free quick-connect fittings. This makes it possible to remove a server from a rack just as easily as a conventional server. Next, using a service tool developed by LSST, fluid can be drained from the server in less than two minutes. After removing a few screws and opening the enclosure, components can be added or removed in the same manner as with a conventional server. After re-securing the enclosure, the server can be refilled using the same service tool, again in under two minutes. Any residual fluid can be cleaned up easily with glass cleaner and a paper towel.
Yes. LSST servers use off-the-shelf components. Standard configurations are offered, but it is simple to customize CPU, GPU, memory and storage.
Compared to an air-cooled server with identical specs, the upfront costs of a four node device are about equal on a per-node basis. However, with substantially higher efficiency and component density, upfront capital expenditures and operating costs are significantly reduced compared to traditional equivalents. See our case studies to see how LSST can save you money from day one.
A very long time, LiquidCool submerged servers are designed for extreme reliability. Our total immersion and sealed system design eliminates nearly all major causes of electronics failures. Components are protected from oxidation, corrosion, dust, electrostatic discharge, and humidity. The servers have no moving parts, no fans to fail, and no vibration which can stress components. Liquid-cooling keeps components cooler than with air-cooling and temperature fluctuations are minimized. In an ongoing test, a system of LiquidCool submerged servers has been in continuous operation for nearly five years. After over 250,000 device hours at 100% CPU load there have been no failures or changes in cooling performance and periodic inspections of the servers have shown them to be in ‘like new’ condition after years of operation. Bottom line, you can be confident that LiquidCool submerged servers will operate reliably over the entire useful life of the product, whether that be three years, five years, or more.
Clean as a whistle – components after 36 months of continuous operation
LSST cooling of IT equipment offers five key advantages over air-cooling:
- Extreme energy efficiency. Because LSST cooling eliminates fans and cools far more efficiently than air, the power to cool servers is reduced by up to 98% compared to air-cooling. Further energy savings are gained because the need for air conditioning and air-handling systems is virtually eliminated.
- Extreme reliability. LSST total immersion cooling eliminates the causes of most electronics failures, such as oxidation, corrosion, heat, temperature fluctuations, and vibration. As a result, mean-time to failure is expected to be much longer compared to conventional computing systems.
- High Performance Computing. LiquidCool Solutions patented directed-flow cooling excels at removing heat from high-density components. LSST cooling can easily support compute densities in excess of 50kW per server rack.
- Harsh Environment Operation. LSST systems package electronics within sealed metal enclosures, protecting components from the effects of oxidation, corrosion, dust, dirt, humidity, and electrostatic discharge. LSST systems are also capable of operating at temperatures well below freezing and at temperatures above 100°F.
- Silent Operation. LSST systems have no fans and the only moving parts are centralized pumps to circulate dielectric fluid through the system. The decibel level at point of use is typically less than can be measured. In other words, silent.
No. Mineral oil is a refined petroleum oil, which can contain contaminants. Instead, the coolant used in LSST systems is a synthetic hydrocarbon oil specially formulated for electronics cooling and to meet military standards for aeronautics applications. LSST coolant has roughly half the viscosity of mineral oil, which reduces the pumping energy needed to circulate the coolant. It also contains additives to prevent oxidation and promote extremely long coolant life. LSST coolant is low-cost, 100% non-volatile, non-hazardous, and never needs replacement over the life of the system.