Home » Heater Hire » Direct Vs Indirect Heaters

The Difference Explained

Aqua Hire can offer both Indirect and Direct Fired Heater hire units depending on your space Heating requirements. Below we’ve given an outline of the main differences between the two options, however our Hire team are always on hand, to give you as much assistance as you need re: product selection and suitability.

Nationwide Coverage

Our Direct And Indirect Fired Heater units and specialist engineers are based right across the UK, ensuring Aqua Hire offer customers nationwide coverage, every day of the year. When you Hire from Aqua, you have the benefit of knowing that one of our engineers is never too far away and can support your business 24/7. Whether it’s an initial site visit or final site delivery, we are used to working quickly! Aqua can offer next-day delivery on a range of Cooling and Heating equipment and our minimum hire period starts from just one week.

Wherever you are in the UK, our top priority is to get your business up and running with minimal disruption and downtime. In emergency breakdown scenarios, a fast response is important and with a network of F-Gas engineers and Gas Safe engineers across the UK, we’re able to offer that every time.


Indirect Fired

Indirect Fired Heaters are primarily designed to be used in areas that have limited ventilation or in situations where combustible materials are nearby.

The fuel itself (diesel oil) is injected into a gas-tight combustion chamber, it’s then ignited and burnt at a regulated rate.

The resulting effect is a continual large volume of safe, clean, dry heat.

These Indirect Heaters are often used for space heating applications where people are involved – for example in halls and marquees.

They can also be used for drying during construction or in disaster recovery after flooding.

Click here for more information about Aqua Hire’s range of Indirect Fired Heaters

Direct Fired

A Direct Fired Heater differs in that, once the fuel is ignited and burnt, it’s expelled with the main air stream to deliver a large volume of heat. They operate on diesel oil or kerosene.

These Heaters aren’t suitable if combustible materials are nearby or if there’s limited ventilation, for example in a marquee. These models operate on oil or gas. The resulting effect is large volumes of warm air.

With the Direct Fired Heater model, ventilation is very important because the heating process adds moisture to the air during combustion. So, these Heaters aren’t ideal for drying applications or in a scenario where an increase in humidity may cause damaged to surrounding materials – for example if you were storing paper – see our Indirect Heater range

These Direct Fuel Heaters can be thermostatically controlled, giving automatic operation and ensuring you’re only using the fuel you need to and keeping a handle on your fuel bills. Direct fired units are commonly used in large factories or warehouses.

Click here for more information about Aqua Hire’s range of Direct Fired Heaters

Cooling/Heating Calculators

Our calculator tool will quickly help you determine an approximate heating and/or cooling capacity for comfort cooling purposes. You simply enter a few key facts and then press “calculate” for a guide figure which is often helpful for initial planning purposes.

To get an exact calculation you’ll need to factor in other variables, for example any HVAC equipment already on site. Our hire specialists are highly trained and experienced in a range of cooling and heating applications. They’ll help you every step of the way, from working out capacity required and product selection right through to getting the right equipment on site.

Click Here to view Aqua’s Cooling and Heating Calculators

cooling and heating calculators

Comfort Heating Enquiry?
Before you call…

There’s some key information that will enable our hire specialists to find the best solution for you as quickly as possible and we’ve detailed this below. These answers will help speed up the quotation process and our overall response time from enquiry to delivery/installation – essential in an emergency scenario. If you don’t have all the answers to hand then our team will help guide you through the process and can always arrange a free, no obligation, site visit if needed.

  • Minimum time you’ll require the equipment for
  • Approximate room/building size – width/length/height – photos or floor plans are really useful
  • Number of occupants within the space
  • Number of windows and doors within the space, are they easily accessible and are any fire doors?
  • Details of any computers or other machinery within the space
  • Location – ground floor or otherwise
  • Is noise a consideration? We have low noise equipment options available
  • Any access/delivery restrictions to overcome?
  • Availability of outside space – if siting equipment externally

Our Cooling and Heating Calculators will also help you to work out an indicative cooling/heating capacity.

Direct Vs Indirect Heaters
Service Type
Direct Vs Indirect Heaters
Provider Name
Aqua Hire,
Unit D4, Segensworth Business Centre,Fareham,Hampshire-PO15 5RQ,
Telephone No.0333 004 4433
United Kingdom
Direct or Indirect Heaters? Aqua Hire can offer both Indirect and Direct fired Heaters depending on your space Heating requirements. Not sure which type will suit your requirements? Call our experienced Heating Hire Engineers for help with product selection.