If you own or manage a strip center, restaurant, office suite, or light industrial building in Schaumburg or Palatine, your rooftop units are doing more work than anything else on the property — and getting the least attention. Most commercial RTUs in the northwest suburbs were installed between 1998 and 2012. That puts a large share of them at or past the end of a realistic 15-to-20-year service life, right as refrigerant availability and parts supply are tightening.
This guide is written for building owners and facility managers making the repair-or-replace call, and it covers what the work actually costs, what drives those numbers, and how to sequence a replacement so tenants never lose a business day.
When Repair Stops Making Sense
The honest framework we use on commercial equipment:
Repair is usually still the right call when
- The unit is under 12 years old and the failure is a contactor, capacitor, motor, or board
- The cabinet, coils, and heat exchanger are sound
- The repair is under roughly 25% of replacement cost
- The unit still runs on a refrigerant you can source at reasonable cost
Replacement is usually the right call when
- The compressor has failed on a unit older than 12 years
- The evaporator or condenser coil is leaking on an R-22 unit
- You have had three or more service calls in 18 months
- The heat exchanger is cracked — that is a safety condition, not a maintenance item
- The cabinet base is rusted through and holding water
The refrigerant question deserves its own note. R-22 units are long out of production and reclaimed refrigerant pricing makes a major leak repair economically painful. R-410A equipment is now in its own transition as the industry moves to lower-GWP refrigerants such as R-454B under the current HFC phasedown. Practically, that means a 2026 replacement decision on a leaking R-22 unit is not close — you are pouring money into a machine you will replace anyway within a couple of seasons.
Commercial RTU Replacement Cost Ranges
| Unit Size | Typical Application | Installed Cost Range |
|---|---|---|
| 3 – 5 tons | Small office suite, single retail bay | $9,000 – $16,000 |
| 7.5 – 10 tons | Restaurant, mid-size retail, medical suite | $16,000 – $30,000 |
| 12.5 – 15 tons | Larger retail, small warehouse zone | $28,000 – $48,000 |
| 20 – 25 tons | Big-box zone, manufacturing area | $45,000 – $80,000+ |
Ranges are for gas/electric packaged units with standard controls, installed in the Chicago northwest suburbs. Line-item variables that move the number:
- Curb adapter vs. matching curb ($800 – $2,500 per unit). New equipment rarely matches a 20-year-old curb footprint.
- Crane day ($1,200 – $3,500). This is why replacing three units on one day is dramatically cheaper per unit than replacing them one at a time across three seasons.
- Electrical service and disconnect updates. Higher-efficiency units sometimes change MCA/MOCP requirements.
- Economizer, smoke detectors, and controls. Often required by current energy code even if your old unit lacked them.
- Roof curb and flashing repair, which you should expect to find once the old unit comes off.
- Permits and inspection, which in Schaumburg and Palatine are straightforward but must be pulled by a licensed contractor.
Efficiency and Operating Cost: What Actually Pays Back
Current commercial packaged units are meaningfully more efficient than the 2005-era equipment they replace, especially at part load. The features that generate real savings for northwest suburban buildings:
- Two-stage or variable-capacity compressors — buildings almost never need full capacity, and part-load efficiency is where the annual dollars live.
- ECM supply fan motors — often the single largest electrical savings item in a retail space with long runtime hours.
- Functional economizers — free cooling on Chicago spring and fall days is substantial, and a large share of existing economizers on older RTUs are broken or disabled.
- Demand-controlled ventilation — particularly valuable in restaurants and gyms with variable occupancy.
Depending on runtime, a 10-ton replacement typically trims 20% to 35% off cooling energy. Check current ComEd and Nicor commercial prescriptive incentives before you sign; on qualifying high-efficiency equipment they can offset a real portion of the equipment cost, and the paperwork has to be filed before installation in most programs.
Sequencing the Work So You Never Close
The concern we hear most is downtime. A single-unit changeout on a prepared curb is a one-day job, and with an adapter it is usually still one day. Practical tactics:
- Do it in the shoulder season. April–May and September–October give you weather margin. A July changeout means the space is warm for a few hours no matter how well it is planned.
- Pre-stage the curb adapter so crane time is spent lifting, not fabricating.
- Phase multi-unit projects by zone, replacing the units serving the least occupancy-sensitive area first.
- Schedule the crane once. If you have four aging units, replacing all four on one crane day can save $4,000 to $8,000 versus spreading them out.
- Plan for after-hours work in restaurants and retail. It costs more in labor but nothing in lost revenue.
What to Get in Writing Before You Sign
- Model numbers, tonnage, efficiency ratings, and refrigerant type
- Whether a curb adapter is included, and who fixes roofing penetrations
- Crane and rigging responsibility
- Permit and inspection handling
- Startup, commissioning, and economizer verification
- Warranty terms — compressor, parts, and labor stated separately
- Disposal and refrigerant reclamation documentation
Frequently Asked Questions
How long should a commercial RTU last in Chicagoland?
Fifteen to twenty years with consistent maintenance. Units on restaurants and buildings with heavy grease or chemical exhaust often fall to ten to fifteen because of coil corrosion.
Can I replace just the compressor?
You can, and on a younger unit it can be sensible. On a 15-year-old R-22 unit, a compressor replacement frequently costs 40% to 60% of a new unit with none of the warranty or efficiency.
Do I need a permit in Schaumburg or Palatine?
Yes. Like-for-like commercial mechanical replacements require a permit and inspection in both villages, and the contractor must be licensed and bonded with the municipality.
What maintenance keeps a new RTU alive?
Quarterly filter changes at minimum, semi-annual coil cleaning, belt and bearing inspection, economizer function checks, and annual heat exchanger inspection. Our maintenance agreements cover this on a fixed schedule.
Is financing available for commercial equipment?
Yes. We work with Sunbit and PowerPay, and for larger multi-unit projects we can structure phased billing across budget years.
Get a Real Number on Your Roof
MMDS provides commercial HVAC service, RTU replacement, and preventive maintenance for buildings in Schaumburg, Palatine, and throughout the northwest suburbs. We will survey every unit on your roof, document age, refrigerant, and condition, and give you a prioritized replacement plan instead of a single scary number.
Call (847) 221-6280 or schedule a rooftop survey.