Help & Guidance — Purple Haze MK
What Is Sub-Ohm Vaping?
Sub-ohm vaping means vaping with a coil that has an electrical resistance below 1.0 ohm. Lower resistance lets more power flow through the coil, heating it faster and hotter — producing larger vapour clouds, warmer vapour and more intense flavour. It requires specific gear and low-nicotine e-liquid and is better suited to experienced vapers than beginners.
An ohm (symbol: Ω) is the unit that measures electrical resistance in your vape coil. The coil is the heated wire element that vaporises your e-liquid. Higher resistance means more opposition to electrical flow — the coil heats more gently, uses less power and produces less vapour. Lower resistance means less opposition — the coil heats faster and more intensely, vaporising more liquid and producing much larger clouds. Sub-ohm means any coil resistance below 1.0Ω. In practice, most cloud-focused sub-ohm setups use coils of 0.2Ω to 0.5Ω and are paired with high-wattage devices (40W to 100W+), high-VG e-liquids and very low nicotine strengths of 0mg to 6mg. The inhalation technique is direct-to-lung (DTL) rather than the mouth-to-lung (MTL) draw of a cigarette.
Resistance Ranges and Vaping Styles Explained
| Resistance range | Style | Wattage | Inhale type | Best for |
|---|---|---|---|---|
| 1.2Ω to 0.8Ω | Mouth-to-Lung (MTL) | 10–20W | Draw into mouth, then inhale | Beginners, ex-smokers, nic salts, tight draw |
| 0.7Ω to 0.5Ω | Restricted Direct-to-Lung (RDTL) | 20–40W | Semi-direct, slightly open | Transitioning vapers, flavour focus, moderate clouds |
| 0.5Ω to 0.3Ω | Direct-to-Lung (DTL) — sub-ohm | 30–60W | Direct inhale to lungs, open airflow | Experienced vapers, larger clouds, warm vapour |
| Below 0.3Ω | High-power DTL — cloud chasing | 50–100W+ | Full direct-to-lung, maximum airflow | Advanced vapers, cloud chasing, high performance |
MTL vs DTL: The Fundamental Difference
Mouth-to-Lung (MTL) — like smoking
- Draw vapour into the mouth first, then inhale to lungs
- Tighter, more restricted airflow
- Higher resistance coils (0.8Ω to 1.2Ω)
- Lower wattage devices (10W to 20W)
- Higher nicotine strengths (10mg to 20mg)
- 50/50 or higher-PG e-liquids
- Smaller vapour production
- Best for: beginners, ex-smokers switching to vaping
Direct-to-Lung (DTL) — sub-ohm style
- Inhale vapour directly to the lungs in one draw
- Wide-open, unrestricted airflow
- Low resistance sub-ohm coils (below 0.5Ω)
- High wattage devices (40W to 100W+)
- Low nicotine strengths (0mg to 6mg — never higher)
- High-VG e-liquids (70% VG or more)
- Large, dense vapour clouds
- Best for: experienced vapers, cloud chasing, flavour intensity
What Gear You Need for Sub-Ohm Vaping
High-wattage device (mod)
Sub-ohm coils require a device capable of delivering 40W or more. Box mods, pod mods with variable wattage and advanced kit mods all work. The device must support the specific coil resistance you are using — always check the manufacturer's recommended wattage range for each coil.
Sub-ohm tank or pod with low-resistance coils
Your tank or pod must be designed for sub-ohm use with coils below 0.5Ω for genuine cloud performance. Mesh coils are now standard in most sub-ohm hardware — the large surface area heats quickly and evenly, improving both cloud production and flavour.
High-VG e-liquid (70% VG minimum)
VG (vegetable glycerine) is the thick, viscous ingredient that produces dense vapour. PG (propylene glycol) carries flavour and produces throat hit. Sub-ohm vaping requires high-VG ratios — 70/30 VG/PG is the minimum, with 80/20 or max VG preferred. High-PG liquid will taste harsh and dry your coil rapidly at sub-ohm wattages.
Low nicotine — 0mg to 6mg only
The large vapour volume produced by sub-ohm vaping delivers far more nicotine per puff than MTL vaping. Using standard 10mg or 20mg e-liquid in a sub-ohm setup would deliver an unpleasant, potentially dangerous nicotine overdose. Always use 0mg to 6mg freebase nicotine with sub-ohm kits. Never use nicotine salts in sub-ohm devices.
Wide-open airflow
Sub-ohm coils produce more heat and need substantial airflow to cool the vapour and make the direct-lung inhale comfortable. Sub-ohm tanks and pods have adjustable wide airflow systems. Open the airflow fully when using the lowest resistance coils at the highest wattages.
Adequate battery capacity
High wattage draws significantly more power from batteries than MTL vaping. A 3000mAh to 5000mAh battery is recommended for all-day sub-ohm use without needing to recharge mid-session. External battery mods using 18650 or 21700 cells are popular with advanced sub-ohm vapers for their battery life and replaceability.
Sub-ohm means any coil resistance below 1.0 ohm — most serious cloud setups use 0.2Ω to 0.5Ω coils with wattages of 40W to 100W or more
Never use high-strength nicotine in a sub-ohm device — the large vapour volume makes even 6mg deliver a strong hit; 10mg or 20mg would be unpleasant and unsafe
Sub-ohm vaping requires high-VG e-liquid for dense cloud production — high-PG liquid will taste harsh and burn through coils rapidly at sub-ohm wattages
Is Sub-Ohm Vaping Right for You?
Sub-ohm vaping is not suitable for everyone and is not the best starting point for beginners or recent ex-smokers. The following guidance helps you decide:
- If you are brand new to vaping or recently switched from cigarettes: start with a MTL pod kit at 10mg to 20mg nicotine strength. This most closely mimics the sensation of smoking and will be far more satisfying than trying to adapt to sub-ohm immediately.
- If you have been vaping for several months on a MTL setup and want bigger clouds, more intense flavour and a warmer vape: sub-ohm is a natural next step. Move down to 6mg nicotine first and try a pod mod with 0.5Ω to 0.6Ω coils before going to fully open DTL.
- If you want maximum cloud production and are experienced with vaping: dedicated sub-ohm tanks with 0.2Ω to 0.3Ω mesh coils on 50W to 80W regulated mods deliver the best cloud performance.
- If you primarily need discretion for use in work, public or travel settings: sub-ohm is unsuitable — the large vapour clouds are highly visible and draw attention. A compact MTL pod kit is far more practical for discreet use.
Sub-ohm vaping is safe when done correctly with appropriate equipment, the right e-liquid and the right nicotine strength. Modern regulated devices include multiple safety protections including short-circuit protection, overheat protection and battery safety cutoffs. The risks associated with sub-ohm vaping come primarily from using incompatible equipment, wrong nicotine strengths or unregulated devices without safety protections. Always buy from reputable UK retailers, check that products are TPD-compliant, and follow the manufacturer's recommended wattage range for every coil.
Part of Our Guide
Help & Guidance Centre
This article is part of the Purple Haze MK Help and Guidance Centre. For more vaping guidance, visit the Purple Haze MK Help and Guidance Centre.
Frequently Asked Questions
Can I use my regular e-liquid in a sub-ohm device?
It depends on your e-liquid's VG/PG ratio and nicotine strength. High-PG or 50/50 e-liquids are not ideal in sub-ohm setups — they can taste harsh at high wattages and drain the coil quickly. More importantly, if your regular e-liquid contains 10mg or 20mg nicotine, do not use it in a sub-ohm device — the large vapour volume would deliver too much nicotine per puff. You need high-VG liquid (70%+ VG) and a maximum of 6mg nicotine for sub-ohm use.
Is sub-ohm vaping more harmful than regular vaping?
Current evidence does not indicate that sub-ohm vaping is significantly more harmful than standard vaping for adults who use it correctly — both are substantially less harmful than smoking. The key safety considerations with sub-ohm vaping are using the correct (low) nicotine strength and using a regulated device with built-in safety protections. Using high-nicotine e-liquid in a sub-ohm setup would increase nicotine intake to unsafe levels.
What is cloud chasing?
Cloud chasing is the hobbyist practice of producing the largest possible vapour clouds, often using extreme sub-ohm setups with coils below 0.2Ω, wattages above 100W, maximum VG e-liquids and zero-nicotine liquids. Some cloud chasers compete in organised events. It represents the advanced end of sub-ohm vaping and requires significant knowledge of battery safety, coil building and device performance. It is not the same as standard sub-ohm vaping — most sub-ohm vapers are interested in better flavour and satisfying clouds rather than competitive cloud production.
Related Articles
For more vaping guidance, visit the Purple Haze MK Help and Guidance Centre.
Sub-Ohm Kits in Milton Keynes
Purple Haze MK — Vaping Specialists
For expert advice on sub-ohm setups, the right device and the right e-liquid, visit us at Stall 109, Milton Keynes Market. Tue, Thu to Sat 9am to 5:30pm. Sun 10am to 5pm.