If you’re opening a restaurant in Schaumburg or building out a commercial kitchen in Wheeling, the hood system is the single most expensive, most heavily inspected, and most commonly under-scoped mechanical item in the project. It’s also the one that can hold your occupancy permit hostage.
The mistake we see most often isn’t a bad hood. It’s a hood installed without proper make-up air — and that mistake shows up as doors that won’t close, pilot lights blowing out, smoke rolling out of the hood face, and a health inspector who won’t sign off.
Type I vs. Type II: Get This Right First
| Type I | Type II | |
|---|---|---|
| Handles | Grease and smoke | Heat, steam, odor only |
| Required over | Fryers, griddles, ranges, charbroilers, woks | Dishwashers, steamers, ovens without grease |
| Filtration | UL 1978 grease baffle filters required | No grease filter required |
| Duct | Welded liquid-tight 16 ga. black iron or 18 ga. stainless | Galvanized acceptable |
| Fire suppression | Required (UL 300 wet chemical) | Not required |
| Typical cost, 12 ft run | $18,000 – $45,000+ | $5,500 – $12,000 |
Putting a Type II hood over grease-producing equipment is the most expensive shortcut in the business — you’ll be tearing it out. When in doubt, the appliance manufacturer’s data plate and the inspector’s read of your menu govern.
The Make-Up Air Problem
A 12-foot Type I hood over a charbroiler line may exhaust 3,600–4,800 CFM. That air has to come from somewhere. Illinois Mechanical Code requires replacement air for exhaust over 400 CFM, and the reason isn’t paperwork — it’s that a building under strong negative pressure misbehaves in specific, diagnosable ways:
- Entry doors that are hard to pull open, or slam
- Hood that “spills” smoke into the kitchen despite correct CFM
- Water heater or boiler backdrafting — a carbon monoxide risk, not just a nuisance
- Toilet exhaust reversing and pulling sewer odor into the dining room
- Heating bills that make no sense, because you’re heating outdoor air pulled in through every crack
In Chicagoland the make-up air unit has to be tempered. Pulling 4,000 CFM of 5°F January air into a kitchen without heating it is not an option. A direct-fired gas MUA unit, interlocked with the hood fan, is the standard solution:
| Component | Typical installed cost |
|---|---|
| Type I hood, 10–12 ft with filters | $6,500 – $14,000 |
| Welded black iron ductwork and roof penetration | $4,500 – $12,000 |
| Upblast exhaust fan (NFPA 96 compliant, hinged) | $2,200 – $5,500 |
| Tempered make-up air unit (3,000–5,000 CFM, direct fired) | $9,000 – $22,000 |
| Wet chemical fire suppression + gas shutoff interlock | $4,500 – $9,000 |
| Electrical: fan disconnects, interlock, controls | $2,500 – $6,000 |
| Gas piping to MUA and appliances | $1,800 – $6,500 |
| Engineering, permits, drawings | $2,000 – $6,000 |
| Complete system, typical build-out | $33,000 – $80,000 |
The variance is driven by roof access, duct run length, whether structural steel needs reinforcement for the curb, and gas service capacity. A build-out where the existing gas meter can’t support a new MUA unit plus a fryer bank means a utility upgrade — find that out during design, not during install.
Six Requirements Inspectors Fail Projects On
- Hood overhang and capture. Type I hoods generally need 6 inches of overhang beyond the appliance on open sides, with mounting height per the listing. Under-sized hoods over deep equipment fail on capture, not on CFM.
- Duct clearance to combustibles. 18 inches unless you use a listed grease duct wrap or enclosure. This is the most common field violation in older buildings.
- Access panels. Cleanable access at every change of direction. Fail this and you’ll be cutting into finished ceilings.
- Fan and gas interlock. Fire suppression discharge must shut off gas to all appliances under the hood, and the hood fan and MUA must be electrically interlocked.
- Upblast fan with hinge kit and grease containment. Non-negotiable under NFPA 96.
- Balance report. Many Cook County jurisdictions want measured exhaust and make-up CFM at final inspection. Plan for a test and balance line item.
Ongoing Compliance After the Install
Your certificate of occupancy is the beginning, not the end:
- Hood and duct cleaning: quarterly for high-volume solid fuel and 24-hour operations; semiannual for moderate-volume; annual for low-volume. Certified cleaning with a dated service sticker is what inspectors look for.
- Fire suppression inspection: semiannual by a licensed contractor, plus nozzle changes when equipment under the hood changes. Swapping a range for a fryer without re-engineering the nozzle layout voids compliance.
- Filter cleaning: weekly at minimum. Grease-loaded baffles kill capture performance and CFM.
- Belt, bearing and MUA burner service: at least annually — ideally on the same visit as the rest of your commercial HVAC maintenance.
Why Single-Source Matters on This Job
A hood project is simultaneously mechanical, electrical and gas piping work. When those are three separate contractors, the interlock wiring, gas shutoff and balance report become everyone else’s problem — and the general contractor absorbs weeks of schedule slip while trades point at each other.
MMDS handles the mechanical, the electrical and the gas piping under one contract, including permit drawings and inspection coordination in Schaumburg, Wheeling and surrounding villages. One number to call when the inspector has a question.
Budgeting Realistically: Where Projects Go Over
Four line items account for most cost overruns we see on Schaumburg and Wheeling kitchen build-outs:
- Gas service capacity. A fryer bank plus a direct-fired make-up air unit can double the building’s gas demand. If the existing meter and service can’t carry it, you’re waiting on the utility — often 6–12 weeks. Load-calculate during design.
- Structural support for the roof curb. A 4,000 CFM MUA unit plus curb is significant rooftop weight. In older strip-center buildings that means an engineer’s review and sometimes steel. Nobody budgets for it.
- Electrical service. Hood fan, MUA blower and burner controls, plus a full kitchen equipment package, frequently push an existing 200-amp service past its limit. A service upgrade is a separate permit and a separate utility coordination.
- Landlord and shell conditions. Roof penetration rights, existing shafts, and required rooftop screening vary by lease and by village. Read the lease before you design the duct route.
None of these are surprises if the mechanical, electrical and gas scopes are designed together. They’re all surprises if the hood is bought first and everything else is figured out later — which is the most common sequence in restaurant build-outs.
Energy Costs and Demand Control Ventilation
A hood exhausting 4,000 CFM for 14 hours a day is exhausting roughly 3.4 million cubic feet of conditioned air per day. In a Chicago January, heating that replacement air is one of the largest single line items on a restaurant’s utility bill.
Demand control kitchen ventilation (DCKV) uses temperature and optical sensors in the hood to modulate exhaust and make-up fan speed based on actual cooking activity. During prep hours and slow periods the fans drop to 30–50% speed. Typical savings run 20–40% of kitchen ventilation energy cost, and DCKV is required by current energy code for larger systems in many jurisdictions anyway. Utility incentives are sometimes available; we’ll check what’s live at the time of your project rather than quoting a stale number. If you’re already committing to variable-speed fans, the incremental cost of controls is usually the best payback in the whole mechanical package.
Frequently Asked Questions
How long does a commercial kitchen hood installation take?
Design and permitting typically run 3–8 weeks depending on the village. Installation is usually 1–3 weeks once equipment is on site. Order the MUA unit early — lead times, not labor, drive most schedules.
Can I reuse the existing hood in a space that was already a restaurant?
Sometimes, and it’s worth checking before you budget a new one. We evaluate the hood listing, duct condition (welded vs. taped), fan compliance, suppression system age, and whether the CFM matches your new equipment lineup. Menu changes are what usually kill reuse.
Do I need make-up air for a small pizza oven hood?
If total exhaust exceeds roughly 400 CFM, plan on replacement air. Small systems can sometimes use transfer air from a conditioned space or an untempered louver with interlock, but that determination belongs to the mechanical engineer, not a guess.
What about ductless recirculating hoods?
Listed ductless systems exist and can work for limited menus in spaces where roof penetration is impossible. Approval is jurisdiction-specific and the filter maintenance burden is high. Treat it as a last resort, not a cost-saver.
Who is responsible if the hood fails inspection?
Practically, the owner’s schedule pays for it. That’s why we do a pre-inspection walk-through against the approved drawings before the official inspection is scheduled.
Planning a Kitchen Build-Out?
MMDS provides commercial mechanical, electrical and plumbing services across Schaumburg, Wheeling, Arlington Heights, Palatine, Des Plaines, Mount Prospect, Glenview, Northbrook, Skokie and Evanston. Bring us in during design and we’ll size the exhaust and make-up air together, flag gas and electrical capacity issues early, and give you one budget number you can hold.
Call (847) 221-6280 or request a commercial consultation.