Propane or Butane: What’s the Difference? A Practical Guide to Choosing Calor Gas

Trying to decide between propane and butane Calor Gas for your home, caravan, or BBQ? We’ll explain the essential differences in plain English, covering performance, safety, and cost, to help first-time buyers make a confident, cost-effective choice.

Choosing the right type of Calor Gas can make the difference between reliable warmth and frustrating appliance failures, especially if you’re new to home heating, caravanning, or outdoor leisure. Propane and butane are both forms of liquefied petroleum gas (LPG), each with distinct characteristics—some crucial, others simply practical. First-time buyers often focus on price or cylinder size, without realising how temperature, efficiency, or even safety can depend on which gas they choose for their heater or stove.

We’ll break down what genuinely matters: when to use propane and when butane’s a better fit, how this impacts your wallet and environment, and why a good local supplier like Harringtons of Reading matters. By the end, you’ll know which Calor Gas suits your needs, what size to look for, and where to get reliable advice and support.

Understanding Propane and Butane: The Basics

Propane and butane may look similar at first glance, but their performance sets them apart. Both are LPGs—clean, portable fuels stored in pressurised cylinders. Propane’s commonly used at home, in heating and large cooking appliances. Butane, by contrast, often finds its way into compact stoves, portable heaters, or camping kit.

Calor Gas is the best-known brand supplying both gases across the UK. Whether you’re heating a remote cottage, firing up a BBQ, running a boat galley, or keeping cosy in your caravan, you’ll likely use Calor-branded cylinders. In the UK, you will typically see blue Calor Butane bottles and red Calor Propane cylinders*, each compatible with specific regulators and appliances.

If you’re a first-time buyer, pause before grabbing the nearest (or cheapest) bottle. Understanding when to use each can prevent frustration, wasted fuel, and even unsafe setups.

Key Differences Between Propane and Butane

Boiling Points and Temperature Performance

Here’s where propane and butane differ most dramatically. Propane’s boiling point is about -42°C (-43.6°F), meaning it’ll vaporise even in the coldest British winter. That matters because, for an LPG appliance to work, the gas must turn from liquid to vapour inside the cylinder.

Butane, meanwhile, has a boiling point just below freezing at -0.4°C (30.2°F). On a frosty campsite or winter night, butane can freeze up or fail to vaporise. Appliances relying on it may struggle or stop working entirely. For outdoor use, caravanning in shoulder seasons, or unattended cold storage, propane is the safer—and often only—choice.

Energy Output and Efficiency

Efficient heating matters, both for comfort and cost. Propane has a slightly higher calorific value—about 50.35 MJ/kg, compared to butane’s 49.1 MJ/kg (megajoules per kilogram). In plain terms, propane produces more heat per kilo and tends to combust better, especially in low temperatures.

Butane’s efficiency is perfectly adequate for small stoves, lighters, or heating in mild indoor environments. If you plan to heat a house, cook for a family, or run gas appliances outdoors, propane’s superior vapour pressure and output often make it the more practical and cost-effective option.

In financial terms, suppose you use 1,500 kWh annually for heating (roughly £100–£190 per year on LPG, depending on efficiency and tariffs). Choosing propane can mean fewer refills and more reliable energy delivery.

Cylinder Sizes and Storage Options

Calor Propane offers a wide range of cylinder sizes, from portable 3.9kg and 6kg bottles to hefty 19kg or even 47kg tanks for whole-home heating. These vary by regulator fitting (clip-on or screw) and storage location—propane cylinders should always be stored outdoors.

Calor Butane typically comes in 4.5kg, 7kg, or 15kg blue bottles, with smaller canisters available for camping stoves and lighters. Butane bottles often have clip-on connections specifically for portable or indoor appliances. Their size and lighter weight suit quick trips, hobby use, or where mobility is key but output and duration requirements are lower.

Choosing the right size comes down to appliance consumption and storage space. A small 7kg butane canister suits one- or two-ring camping stoves nicely. A 19kg propane cylinder can comfortably feed a combi-boiler, caravan heating, or large BBQ through a cold weekend.

Practical Uses: Which Gas is Best for Your Needs?

Home Heating and Cooking

Propane is almost always the right choice for fixed home heating—whether that’s boilers, large indoor gas fires, or full-sized cookers. Its resistance to freezing and steady vaporisation ensure your appliances run, even when there’s a sudden cold spell.

Butane finds its niche in smaller, portable indoor heaters and lightweight gas rings. Many tabletop stoves, compact heaters, and decorative flame lamps are designed around butane, thanks to its mild-weather performance and manageable canister size.

Caravanning, Boating, and BBQs

Propane excels where you need fuel that works—every time, anywhere. If you’re towing a caravan for winter escapes, running a galley on the Thames, or cooking at a riverside BBQ, choose propane. It performs better outdoors, copes with fluctuating temperatures, and supplies a consistent flame.

Butane remains popular for spring or summer camping, day trips, and lighters or lanterns where failure isn’t critical, weight is a priority, and the temperature’s unlikely to drop far below 0°C overnight.

In summary: if unsure, propane’s more flexible for British weather. Butane serves best where compactness and room temperature use trump outright power.

Safety and Environmental Considerations

Safety Features

Both propane and butane are non-toxic, but—like all LPG—they’re heavier than air, so leaks can collect at ground level. To aid safety, Calor Gas adds a chemical odorant so even a small leak is easy to detect by smell.

Safe use involves sturdy, upright cylinder storage in well-ventilated spaces—never in garages with open drains or cellars. Regulators must match the gas type and be installed according to WRAS (Water Regulations Advisory Scheme) guidance. Always shut off the cylinder when changing appliances, and check rubber hoses for cracks or perishing.

Environmental Impact

Calor Propane and Butane are both classed as clean-burning fuels—producing much less particulate and carbon pollution than oil or coal. Of the two, propane emits slightly less CO₂ per energy unit (229g CO₂/kWh for propane vs. approximately 239g CO₂/kWh for butane). Both offer a notable drop in greenhouse emissions compared to older oil burners or petrol generators.

For those conscious of reducing their carbon footprint without access to mains gas, LPG from Calor remains a straightforward, lower-impact option.

Calor Gas vs. Oil and Mains Gas

Flexibility and Convenience

Not every rural home has access to mains gas. Calor Gas cylinders bring instant heating and cooking fuel without trenching roads or major works. LPG can be delivered, exchanged locally, or even picked up if you’ve got suitable transport.

Switching from oil or electricity to LPG is often attractive for those wanting cleaner, consistent fuel without major upfront investment. If you’re putting a heating system in a new extension, doing up a boat, or fitting out a garden building, Calor Gas can be simpler and quicker than running new gas pipes.

Cost and Pollution Comparison

On cost, LPG is generally competitive, though prices fluctuate (roughly 6–10p/kWh delivered, compared to 4–6p/kWh for mains gas and 6–9p/kWh for domestic oil—these ranges depend on supplier and usage).

*Calor also produce red and black “FLT” propane cylinders, for use on Fork Lift Trucks, plus a “Patio” range of small green cylinders for barbcues and outdoor heaters.

To find out more detailed information about the different types of Calor Gas and their various ratings, visit our Calor Gas Stats page, here…