Pod systems have become the dominant hardware category in vaping retail, overtaking the pen-style kits and tank-and-mod combinations that defined the market in earlier years. Their rise reflects a genuine improvement in the technology: pods deliver excellent flavour and nicotine satisfaction in devices that are compact, discreet, and far simpler to operate than the variable-wattage boxes and complex coil systems they have largely displaced for everyday use. Within the pod category, however, there is a fundamental split that many buyers do not fully understand before making their first purchase: the distinction between open pod systems and closed pod systems.
This distinction has practical consequences for your ongoing cost, your flavour options, and the overall experience of using the device. Understanding it before you buy saves both money and frustration.
Closed Pod Systems: What They Are
A closed pod system is one where the pods are sealed, pre-filled units. You purchase the pods containing both the e-liquid and the coil, already assembled. When the liquid is exhausted, you discard the entire pod and install a fresh one. The only user action required is inserting a new pod and charging the battery. There is no liquid to pour, no coil to change, and no tank to reassemble.
The simplicity of closed systems is their defining advantage. They are the nearest equivalent to the cigarette experience in terms of user interaction: you consume the unit and replace it when empty. This makes them particularly well-suited to new vapers who are not yet comfortable with the mechanics of refilling and maintenance, and to experienced vapers who want a genuinely low-effort backup device for travel or the times when their main setup is impractical.
The limitations of closed systems are also rooted in this simplicity. You are entirely dependent on the manufacturer for your e-liquid supply. The flavour range is limited to whatever the manufacturer produces in pod format, which is invariably a fraction of the options available in the open e-liquid market. The cost per millilitre of e-liquid consumed via a closed pod is substantially higher than buying equivalent liquid in bottles. And if your favourite flavour is discontinued or becomes unavailable, your device is rendered useless for that preference regardless of its remaining battery life.
Open Pod Systems: What They Are
An open pod system uses pods that are refillable by the user. The pods contain a coil but no liquid; you fill them from any compatible e-liquid bottle. When the pod runs dry, you refill it. When the coil inside the pod is exhausted, you either replace the pod (in systems where the coil is integrated with the pod) or replace just the coil head inside a reusable pod shell (in systems designed this way).
Open systems access the full range of the e-liquid market. Any liquid in the appropriate PG/VG ratio for your pod and coil combination can be used, giving you access to thousands of flavour options rather than the dozens available from a single manufacturer. Cost per millilitre drops significantly compared to pre-filled pods. You can switch between flavours at will by simply rinsing the pod and refilling with a different liquid, rather than being locked into whatever is currently loaded.
The trade-off is a small increase in operational complexity. Refilling a pod takes thirty seconds once the technique is established, and replacing a coil head takes a similar amount of time with practice. For most vapers, this level of engagement with the device is entirely manageable. For users who find any degree of maintenance off-putting, the closed system may remain preferable despite its other limitations.
Coil Integration: Pods vs Separate Coil Heads
Within open pod systems, there is a further distinction worth understanding. Some open pods integrate the coil into the pod itself, meaning that when the coil is exhausted, the entire pod is replaced. Others use a separate coil head that sits inside a reusable pod shell, with only the coil head being replaced when exhausted.
Systems with integrated coil pods are simpler to maintain: when the flavour degrades, you discard the pod and install a fresh one. The disadvantage is that you are discarding the pod shell every time the coil burns out, even though the shell itself is perfectly functional. This creates more waste and higher running costs than systems with replaceable coil heads.
Systems with separate coil heads are more cost-efficient and generate less waste. The pod shell can be reused many times, with only the coil head replaced at roughly one to three week intervals. The additional step of removing the old coil head and installing the new one adds a small amount of complexity that integrated pod systems avoid.
Nicotine Salt Compatibility
Most pod systems, both open and closed, are designed with nic salt e-liquids in mind. The low wattage at which pod coils typically operate is well-matched to the faster-absorbing, smoother nicotine delivery of nic salt formulations. The higher nicotine concentrations that nic salts allow, up to twenty milligrams per millilitre under TPD regulations, make them particularly suitable for ex-smokers who need robust nicotine delivery in a discreet package.
Open pod systems give you the freedom to use any nic salt product from the full market range, which is an important advantage given the difference in quality and flavour variety between different nic salt brands. Closed systems restrict you to the manufacturer nic salt product line, which may or may not include the concentration range and flavour profile that suits you best.
Some open pod systems also accommodate standard freebase nicotine liquids in lower concentrations and moderate VG content, making them usable as versatile devices for vapers at different stages of their nicotine reduction journey. Closed systems generally do not offer this flexibility.
Which Should You Choose?
For a first-time vaper who wants the lowest possible barrier to getting started, a closed pod system from a reputable manufacturer provides a genuinely simple entry point. The setup requires no technical knowledge, the ongoing operation is intuitive, and the quality of nicotine delivery from the best closed systems is genuinely excellent. The higher per-millilitre cost is a reasonable trade-off for the simplicity during the initial learning period.
For anyone who has been vaping for more than a few weeks and has established their preferred nicotine concentration, the open pod system is almost always the better long-term choice. The access to the full e-liquid market, the significantly lower running costs, and the flexibility to adapt as your preferences evolve make it a categorically superior option for anyone prepared to invest the small amount of time needed to learn the basic refilling and coil replacement process.
Many experienced vapers use both: a quality open pod system as their primary device for everyday use, and a closed pod device or a stock of disposable vapes for situations where the open system is not practical. This hybrid approach captures the advantages of both formats while managing the limitations of each.