The following information is provided courtesy of The Catering Equipment Suppliers Association.

Down to Basics 

The Catering Equipment Suppliers Association (CESA) has drawn up the following basic explanation of the main cooking equipment in a professional kitchen. (Note: Combi-ovens, ranges, microwaves and fryers are covered in separate guides)

Convection ovens

While many ovens underneath cooking ranges rely solely on the natural convection of hot air in the oven cavity to spread the heat, in a convection oven, the heat is spread very evenly around the cavity by means of an electric fan built into the wall of the oven. This gives very even cooking for all foods, but it is especially important in bakery and dessert work where evenness of temperature is critical. 

Because the heat is forced around the oven cavity, cooking is faster, so on standard recipes either the cooking time or the temperature needs reducing. While a combi-oven will perform all the functions of a convection oven, if a lot of dry air baking and roasting is done, it pays to buy a convection oven to free up the combi-oven for cooking tasks which require its steaming function. 

Key points to look for 

Is there a humidifier feature that will inject a moderate amount of steam to aid crisping on baked goods? 
Is there variable fan speed to allow for cooking delicate goods? 
Is there a timer/programming facility? 
Will it do cook and hold?  

Grills and salamanders 

These are two words for the same item of equipment and there are two types available. The conventional grill is usually gas powered in the UK, but electric models are available. Some have variable heat settings that adjust the cooking temperature, but raising or lowering the grill tray with the heat full on is the usual method as this keeps cooking even. An additional item popular for meat grilling is a branding plate. This is a ridged cast ironplate that sits on the grill pan. When a piece of meat is put on the brander plate it cooks from both sides and has a char-grilled appearance. 

The less common type of grill is a pull-down grill. These are usually electric and work the reverse of a conventional grill. The grill plate is static while the radiant head is pulled down towards the food. They are popular for gratineeing and browning cheese-topped dishes.

Key points to look for 

Cleaning is a big headache with grills. See how easily it strips down and to remove traces of carbonised food and fat.
Griddles and char-grills 
Griddles are a very simple item of cooking equipment, popular for breakfast preparation, burgers and any thin food items, but are slow to cook thick portions of meat such as steaks or chops.

There are two surfaces to choose from. Steel is the cheaper and most popular, either as carbon steel or stainless steel. Chromed griddles cook the same, but tend to be less prone to food sticking and are easier to keep clean. 

Char-grills are popular for the barbecue look and taste they bring to meat, fish and vegetables. There are two popular systems of delivering the heat, almost always coming from gas. Lava rock is the most common and gives a traditional barbecue taste and smell. Its drawbacks are that the lava rock can become impregnated with food, which when it burns off creates a lot of smoke in the kitchen and distribution of the lava rock has to be very level to give even cooking when the char-grill is full. 

The other system is not to use lava rock at all, but to have upward-facing gas jets that are shielded by a protective steel shroud to prevent fat falling into the jets and clogging them. As the fat falls onto the hot protective covers, it carbonises and gives of the smoke that brings the barbecue flavour. This system is easier to clean. 

Key points to look for 
With griddles, check how easy it is to clean the fat chute and collection tray and ensure the heat settings meet the purpose for which you mainly intend to use it. Check the uniformity of heat across the full cooking surface. If you need it, see if there is both manual heat control and thermostatic control. 

With char-grills, cleaning is a big issue, ensure there is easy access for cleaning. See if there is a split level facility to enable part of the grill irons to be lifted for cooking more delicate foods or those which require longer cooking time.

Steamers 

Steamers lost some popularity with the advent of combi-ovens, but are a very useful item of equipment where a lot of steaming is done in the kitchen such as with fish, vegetables or steamed puddings. Having a dedicated steamer prevents tying up the combi-oven for long periods of steaming when it is needed for other cooking modes. 

There are two types of steamer. A pressure less steamer cooks with steam at normal atmospheric pressure and is very gentle for items such as fish. A pressure steamer is like a domestic pressure cooker, working with a sealed chamber that allows the steam temperature to rise, so cooking faster and able to tenderise tough cuts of meat.