Heat and thermodynamics
The second part of Revelations introduced a new feature: Heat. With Heat came the option of overloading your modules for an extra performance boost. When you need to squeeze a few more shield hit points out of your shield booster, or you need to deal just a little bit more damage to your opponent, you can overload your modules for extra effect.
The drawback of overloading is the generation of heat. Prolonged exposure to heat will damage and eventually knock your modules offline, making them unusable until they have been repaired.
Heat is distributed over racks, which cover your High, Medium and Low power slots. Heat will spread over the rack causing heat damage to some or all modules on the rack. This means that you can damage many modules while only overloading one module. Multiple overloaded modules will cause increased heat consumption on the rack and faster damage to your modules. It is thus advised to treat this with caution.
Different modules cause more damage (per cycle) than others when overloaded. You can find out the exact amount with the Show Info tool. Heat damage is spread across their respective fitting class (referred to as racks). High slot modules overheat and cause damage to high slot modules, Medium slot modules cause damage to other medium slot modules, etc.
Equipped modules in the User Interface have a circle around them. If they are capable of being overloaded, you will notice that there is a button on the top of the ring.
Once activated, the top part of the ring will glow green indicating activation. Your heat consumption is measured above the Capacitor and lists the three racks.
Once modules start taking damage, the rest of the ring around them will start glowing red. A module will be offlined once the ring is completely red.
There are 3 small buttons with "fitting" symbols on them. Their purpose is to overload all possible modules in a rack (high, medium or low) with a single click.
Heat will dissipate slowly, and over time... not its damage.
Heat and Damage Attenuation
Heat builds up quickly, and is slow to dissipate. As modules continue to be overloaded (and active), the amount of heat will rise, and your modules will take damage over time.
It is possible to slow down the rate heat builds up, and reduce the damage modules take from overload:
- De-activate overloading module(s) for a few cycles.
- The Thermodynamics (rank 3, Science) skill not only allows overheating, but it also reduces heat damage by 5% per level.
- By managing one or more heat sink(s) in the module layout of the ship.
As an inactive, but overloaded, module will not generate heat, it will immediately be ready to function at heightened attributes on the first cycle : a great way to sporadically use your non-repeating modules.
The position of an overloaded module in the rack affects the chances of the other modules in the rack to take damage from heat. The further away from the overloaded module they, the smaller the chances are for the other modules to become damaged.
Damage will not spread in a totally random way over the rack. It will most probably hit the overloaded module(s) generating heat. There is less chance of damage being done to modules equipped next to them, with further reductions in chance to modules further away from the overloaded one. The exact formula can be found and discussed in the "Ships & Modules" section of the forums.
The damage spreading "sideways" also depends of the heat dissipation of the different modules :
- Module Groups have specific behavior towards overloading, an afterburner will produce more heat than one missile launcher or a shield booster for instance.
- Tech Levels are getting different heat sustenance levels, some can take the heat better, such as the run of the mill Tech 1 modules that don't suffer from the delicate construction of specialized modules.
- Shield Boost Amplifiers are one of a kind, has they passively double the heat damage for the amplified Shield boosters.
Having the Thermodynamics skill at a high level and clever fittings won't let you overload your modules forever, but it might give you those several additional cycles's advantage that can make the difference between an expensive repair bill and a whole new ship purchase.
You can thereby create heat sinks or buffers by putting less critical modules on the sides of the to-be-overloaded module.
Offline modules and empty module slots function as heat sinks, reducing the heat damage taken over time both locally (nearby overloaded module(s) on same rack) and globally (whole ship). Hence such heat dispersion slots will give you middle-term overload as trade-off.
Indeed, while the heat propagation is specific to a single rack, the effect of heat sinks is cumulative and independent of any single rack (as the calculation is roughly based upon a ratio of enabled to disabled / empty modules). So, the more offline modules, the more damage cooled down and the less chance of the online modules to take heat.
So while it is usually better to fit an active module, if no CPU, power grid or turret/launcher point is available, these heat sink modules can be used to great effect.
Repairing Heat Damage
If you find yourself needing to repair your modules, you can always dock at a friendly station and utilize the repair service. However, you may not always have that option available to you in deep space. If the modules are still online, you can also repair damaged modules with Nanite Repair Paste.
Station repair costs for modules are as follows : up to 50% of base price if the module is partially damaged and up to 100% of base price if the module is fully damaged.
On the other end, Nanite Repair Paste can be quite expensive, and can take up a reasonable amount of space if you intend to overload your modules frequently (0.01m3 per unit, one unit per HP repaired, sold by common empire corporations).
Nanite Operation (A rank 2 skill in the Mechanic category) reduces the amount of paste needed by 5% per level. Nanite Interfacing (a rank 3 mechanic skill) increases the speed of the repairs by 20% per level.
- EVE FanFest 2007 - Heat System Session Overview (external link)