Combi Oven Specs Explained: What Irish Commercial Kitchens Actually Need to Know

If you've started shopping for a commercial combi oven, you've probably noticed the spec sheets don't make it easy. GN capacity, direct steam vs boiler systems, Delta T probes, closed wash cycles - it's a lot of jargon for what's meant to be a straightforward decision. So here's the plain-English version: what each spec actually means, why it matters for an Irish commercial kitchen, and how to match it to what you're actually cooking.

A combi oven is one of the best investments a busy kitchen can make - it roasts, steams, bakes and holds, often replacing two or three separate pieces of equipment. But the wrong spec for your volume either leaves you paying for capacity you'll never use, or queuing at service because you bought too small. Let's break it down properly.

What Is a Commercial Combi Oven, Actually?

A combi (combination) oven blends a convection oven with a steamer, giving you dry heat, steam, or both together in the same chamber. That combination is what lets one unit roast a joint of meat, steam vegetables, bake bread and reheat plated meals - all without shrinkage, drying out, or the flavour loss you get from a standard oven. If you're weighing up a convection oven against a combi, the honest answer is: a convection oven bakes and roasts brilliantly, but it can't steam. A combi does both, which is exactly why kitchens with mixed menus - cafes, gastropubs, hotels, contract catering - tend to land on a combi rather than a straight convection unit.

The Specs That Actually Matter

1. GN Capacity - How Many Trays Do You Actually Need?

Combi ovens are sized by how many 1/1 Gastronorm (GN) trays they hold, and this is the single biggest decision you'll make. In our own range this runs from compact 5-grid units like the UNOX XV393 (5 shelf positions, GN1/1, W750 x D773 x H772mm) right up to large roll-in models like the Giorik Evolution SERE201W, which takes a full trolley of 20 x GN1/1 trays (or 16 x 600x400mm bakery trays).

As a rough guide:

• 5-6 grid suits a cafe, small takeaway or a snack/deli counter doing steady but modest volume.
• 10 grid is the workhorse size for a busy restaurant kitchen or gastropub doing lunch and dinner service.
• 15 grid fits hotels, larger restaurants or venues running events alongside a la carte.
• 20 grid roll-in is built for central production kitchens, large hotels and contract caterers, where you're wheeling in a full trolley rather than loading trays by hand.

Buying bigger "just in case" isn't free - larger units need more floor space, more power, and often a different electrical connection. Buy for your busiest realistic service, not your best-case dream volume.

2. Steam System - Direct Injection vs Boiler

There are two main ways a combi oven generates steam. A direct injection system sprays water onto a heating element or fan, producing steam almost instantly - it's simpler, cheaper to service, and there's less to go wrong, which is exactly the system used across our Blizzard RDA range. A boiler system generates steam in a separate chamber first, which typically gives finer control over steam quality and is more common on higher-spec units - our Giorik Evolution SERE201W, for example, uses a "Supersteam" quality-control system with two levels of steam generation for exactly this reason.

Neither is objectively better - it's a trade-off. Direct injection ovens tend to be cheaper up front and easier to maintain (less scale build-up to worry about in areas with harder water). Boiler systems generally deliver more consistent steam quality for delicate items like fish, patisserie or sous-vide finishing. If your water is hard, ask about a water treatment/softening requirement either way - some of our roll-in models, including the Giorik Evolution, specify that a water treatment system must be fitted for the warranty to remain valid.

3. Temperature Range

Most commercial combi ovens on the market run somewhere between 30C and 300C, though the exact figures vary by model - our Giorik combi range runs +50C to +300C, while the Blizzard RDA range runs +50C to +270C. A wider top-end range matters if you're doing high-heat roasting or pizza-style bakes; if your menu is mostly steaming, poaching and gentle reheating, the lower end of the range matters more than the ceiling.

4. Electric vs Gas

Both are available across most GN sizes - our 6-grid Giorik Combisteamer, for instance, comes in an electric version (400V, 7.9kW) and a gas version (5.5kW gas output plus a small 1.3kW electrical draw for controls and fans). Gas tends to suit kitchens that already have a gas supply and want lower running costs at high volume; electric is simpler to install if you don't already have gas on site, and it's the more common choice for smaller units. Check what's actually feasible in your kitchen before you fall in love with a spec sheet - a gas combi oven is no use to you without a gas connection and the right extraction to go with it.

5. Controls - Manual, Programmable or Touchscreen

This is where price and complexity scale together fast. Our Blizzard RDA range uses straightforward mechanical dial controls with a manual humidity flap - genuinely simple to train new staff on, with less that can go electronically wrong. Step up to something like the Giorik Evolution SERE201W and you get a 7" touchscreen with 120 preloaded recipes, 99 programmable menus with up to 9 cooking phases each, a core temperature probe with "Delta T" cooking mode, and even a USB port for loading new menus or software updates. It also runs an automatic closed-wash cleaning system that uses up to 50% less water than an open wash cycle.

The honest advice here: if your team is small and turnover is high, mechanical controls are genuinely easier to hand over on day one. If you're running a structured menu with consistent dishes across shifts, programmable controls pay for themselves in consistency and reduced training time.

6. Footprint & Power Supply

Don't skip this one - it trips people up constantly. Compact 5-grid units typically run on a single-phase supply, while larger and higher-powered units usually need three-phase power (our Giorik 6-grid electric combi runs on 400V, and the 20-grid Giorik Evolution needs a 415V/63amp three-phase connection). If you're not certain what your kitchen has, get an electrician to confirm before you order - swapping a single-phase kitchen to three-phase mid-fit-out is a cost and delay nobody needs.

Matching Specs to Your Kitchen

If you're running a small cafe or coffee shop with a simple bake-and-hold menu, a compact 5-6 grid electric combi oven with direct steam injection and mechanical controls covers you well, and keeps both the purchase price and the learning curve low. A busy independent restaurant doing two services a day is usually better matched to a 10-grid unit, giving you headroom for a Saturday night without oversizing for a quiet Tuesday lunch. Hotels, event caterers and central production kitchens are the ones who typically justify the jump to 15 or 20-grid roll-in models with programmable controls - the consistency and labour savings across a big menu make the higher spend worth it.

Browse the full range across brands in our Combi Steam Ovens collection, or go straight to Giorik Ovens and Unox Ovens if you already know the brand you're after.

What Does a Commercial Combi Oven Cost?

Prices vary a good bit by GN capacity, controls and brand, so treat these as ballpark ex VAT figures rather than gospel - always check the collection page for current pricing on the exact model you're after. Compact 5-6 grid electric combi ovens with mechanical controls typically start from around €3,000 to €6,500 ex VAT. Step up to a 10-grid model and you're generally looking at somewhere in the region of €8,000 to €12,000 ex VAT, with gas versions and touchscreen controls sitting toward the top of that. Large 15 to 20-grid roll-in units built for high-volume kitchens run from roughly €11,500 up to €26,000+ ex VAT, depending on spec.

FAQ

Do I need a combi oven if I already have a convection oven?
Depends on your menu. If you never steam, poach or need gentle reheating, a convection oven may be all you need. The moment steaming or holding quality matters - veg, fish, batch cooking, plated reheats - a combi earns its keep fast.

Is direct steam injection or a boiler system better?
Neither wins outright. Direct injection is simpler, cheaper and easier to maintain. Boiler-style systems generally give finer steam control, which matters more for delicate or high-precision cooking.

What size combi oven do I need for a small kitchen?
Start with your busiest realistic service, not your peak dream volume. Most small cafes and takeaways are well served by a 5-6 grid model; buying bigger "just in case" mostly just costs you floor space and power.

Does a combi oven need special plumbing or drainage?
Most commercial combi ovens need a water connection for steam generation and a drain for condensate and wash cycles, and larger roll-in units may specify a water treatment system depending on your water hardness. Get your installer to confirm requirements for the specific model before fit-out.

Ready to Choose the Right Combi Oven?

If you're still weighing up GN size, steam system or electric vs gas, we're happy to talk through your menu and service volume and point you at the right spec rather than the priciest one. Browse the full Combi Steam Ovens range now, or get in touch and we'll help you match a model to your kitchen. And if you're kitting out a whole new site, our guide to essential equipment for opening a restaurant in Ireland is worth a read too.