Comparing the Thermoblock vs the Boiler, the Thermocoil and Other Espresso Machine Heating Systems..

除了a great espresso machine, the key to a great espresso shot is consistency. Consistent grind, consistent tamp, consistent temperature. But how do espresso makers manage to deliver shot after shot at the perfect 93 degrees Celsius?

Today there are four primary technologies that heat water for espresso: thermoblocks, boilers, heat exchangers, and thermocoils. Each technology comes with its own benefits and drawbacks.

How a Thermoblock Works

热块是带有嵌入式加热元件和水管的金属块。当水沿着管道的长度上行驶时，它会从块中捡起热量，并在所需温度下退出。水与热水块接触短时间，但是在那段时间，它可以闪烁热量以高到足够高的温度以产生干蒸汽。

最简单的tw thermoblocks是捏造的o plates of metal with a spiral route cut into it for the water to travel through. A gasket is compressed between the two pieces, preventing the system from leaking. Other thermoblocks are simply a length of pipe with a heater attached along its length. (1）

热块的常见材料包括铝，黄铜和不锈钢。一些热块使用复合设计，并带有铝制体内包裹的不锈钢管。

Thermoblocks are inexpensive to produce and also are energy efficient as they only heat water immediately prior to it being used. Many superautomatic espresso machines (like a few oneshere）采用热块系统，可快速加热水。尽管热块能够极快地产生热水，但其温度控制比其他一些加热技术的完美不佳。

It is common for espresso machines to use thermoblocks on the steam side and a boiler for the brew side. This allows the thermoblock to do what it does best, heat water quickly, while avoiding the pitfalls of its inconsistency.

The thermoblock is often put near the group head, providing indirect heating of the brew chamber in addition to heating the water.

浓缩咖啡机如何加热水

Boilers

The original espresso makers used stainless steel boilers heated by open flame, but as time went on they progressed to electric heat. In the 1920s Achille Gaggia invented the lever-operated espresso maker, culminating in the first espresso shot that would satisfy a modern aficionado. His machines used boilers, but instead of steam pressure used a lever-operated, spring-powered piston to drive the water through the grounds. (2）

While lever operated systems have mostly been replaced by pump driven systems, the single boiler heating unit has persisted.

这些咖啡机使用单个锅炉来生产浓缩咖啡和蒸汽的热水，需要额外的护理才能使用。一些单个锅炉系统要求您在酿造和蒸之间的开关时翻转开关（3）。忘记这样做可以通过地面过度热水或导致水太凉而无法有效产生蒸汽。

Heat exchangers

开发热交换器系统是克服单个锅炉的固有局限性的一种方式。热交换器系统从这些系统中的锅炉仅直接加热蒸汽侧的水。

The coffee brew water runs through a copper line that is coiled through the heated water. As the water travels along the line it picks up heat from the steam reservoir and comes up to a temperature sufficient for espresso brewing.

Double Boilers

Double boiler espresso makers employ two separate heating units: one for steam, and one for coffee. With one boiler dedicated to steam and another to espresso, you never have to worry about a long series of milk drinks lowering your espresso brew temperature.

许多商业意式浓缩咖啡机 -就像我们在这些帖子中提到的那样– use double boilers as they churn out consistent espresso shots and steam all day long. See some of the best ones here:

While double boiler systems are great coffee makers, they have several disadvantages. They are bulkier than other heating systems, involve considerable complexity and corresponding cost, have long preheating times, and are not energy efficient as the water is held at temperature constantly.

热胶质

作为相对于热块的亲密关系，热胶机在相同的原理上起作用：一种嵌入在金属运行中的加热元件，并在水管旁边闪烁加热水。虽然热固体的身体通常是铝制的，但嵌入式管道可能是铜或不锈钢等不同材料。这两种技术之间的主要区别在于，热固体是一件单元，因此不会遭受热块泄漏问题的困扰。

Some thermocoils are built into the exterior of boilers. These units serve double duty, heating the water in the brew chamber and then directing water from the tank through the serpentine passages in order to create steam. (4）

与其他热加热单元相比，热胶质机器的主要缺点是它们的成本。

Quick Comparisons

热块与锅炉

Thermoblocks:

• 需要减少预热的时间
• 可以产生恒定的热水
• Are more energy efficient
• 与单锅炉系统相比，温度控制更好
• 与双锅炉系统相比，温度控制较差
• 更容易泄漏
• Are more heavily impacted by scale
• 在需要维修或更换之前，寿命较短

Thermoblock vs Thermocoil

Thermoblocks:

• 费用更低
• Are equally energy efficient
• 更容易泄漏

照顾您的热块系统

对热块的最大危险是钙沉积物的积累，也称为比例。一些材料（例如不锈钢和青铜）积累尺度的可能性较小，但没有任何材料不受问题的影响。（（5）

If your water is hard you are at a greater risk, but even relatively soft water can cause scale accumulation over time. Avoid this by using a water filter. Filters lose their efficacy over time, so change it at the manufacturer’s recommended intervals.

如果您怀疑钙的积累，那么您需要降低机器。您的制造商将详细介绍该过程，大多数主要制造商都有自己建议使用的降落产品。

随着时间的推移，热块加热单元仍然有泄漏的趋势。加热单元最终将需要更换垫圈。根据您的舒适度，这可能是一个DIY项目，或者可能涉及将您的设备发送到维修公司。

There’s more to浓缩咖啡机的工作方式，但是现在您知道其中最技术的一部分！现在去那里，选择您的机器at the right budget，然后酿造！

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