Commercial HVAC Install Problems — Grocery
Fifteen installation problems involving refrigeration coordination, condensation, grease exhaust, make-up air, food-area protection, cold rooms, and store pressure.
What this covers
Use this playbook when installation conditions do not match the plan, the work cannot be completed cleanly, or the crew needs a structured way to inspect the problem before changing the installation.
How to use this playbook
- Identify the exact location, system, installation phase, and affected work.
- Open the closest matching problem below.
- Complete the listed checks before changing or removing installed work.
- Use the field solution only when it matches project requirements and crew direction.
- Apply the prevention note to the next similar installation.
- Stop and escalate whenever the listed stop condition applies.
Problems and field solutions
Coordination · Duct mains1. Duct conflicts with refrigeration piping racks
Open
1. Duct conflicts with refrigeration piping racks
What to check
Check coordinated rack elevations, insulation thickness, valve access, and duct dimensions.
Field solution
Revise approved route or elevation; preserve refrigeration service clearance and duct insulation space.
Prevent it next time
Coordinate refrigeration, electrical, sprinkler, and HVAC racks together.
Stop / escalate
Stop if moving either system affects required slope or access.
Moisture Control · Supply duct2. Duct sweats above refrigerated cases
Open
2. Duct sweats above refrigerated cases
What to check
Check insulation continuity, vapor barrier, air leaks, cold surfaces, and ambient humidity.
Field solution
Repair insulation and vapor jacket; seal air leaks; correct missing thermal breaks and supports.
Prevent it next time
Inspect vapor barrier before ceiling closure.
Stop / escalate
Stop if wet insulation or hidden moisture damage is extensive.
Equipment · Make-up air3. MUA discharge short-circuits into hood exhaust
Open
3. MUA discharge short-circuits into hood exhaust
What to check
Check diffuser placement, hood capture, discharge direction, and design intent.
Field solution
Relocate or redirect approved supply outlets; rebalance with exhaust system.
Prevent it next time
Coordinate hood and MUA air patterns before rough-in.
Stop / escalate
Stop if hood capture is compromised.
Grease Exhaust · Grease duct4. Grease duct route cannot maintain cleaning access
Open
4. Grease duct route cannot maintain cleaning access
What to check
Check access-door locations, elbows, shaft conditions, and listed/code requirements.
Field solution
Reconfigure route or add listed access assemblies as approved; support independently.
Prevent it next time
Lay out cleaning access before fabrication.
Stop / escalate
Stop if any section becomes uncleanable.
Grease Exhaust · Grease duct5. Factory-listed grease duct components from different systems are mixed
Open
5. Factory-listed grease duct components from different systems are mixed
What to check
Verify manufacturer, listing labels, bands, gaskets, and support components.
Field solution
Remove mixed components and rebuild with one compatible listed system.
Prevent it next time
Control receiving and stage listed systems separately.
Stop / escalate
Stop installation immediately; mixed listed systems are not acceptable.
Roof Work · Exhaust fans6. Fan hinge kit cannot open because duct/curb arrangement is wrong
Open
6. Fan hinge kit cannot open because duct/curb arrangement is wrong
What to check
Check fan orientation, hinge swing, wiring, curb, and grease duct connection.
Field solution
Reorient fan/hinge or revise connection with approved components; preserve cleaning access.
Prevent it next time
Review fan service motion before crane set.
Stop / escalate
Stop if fan cannot be safely opened and cleaned.
Air Distribution · Case areas7. Diffusers blow directly into open refrigerated cases
Open
7. Diffusers blow directly into open refrigerated cases
What to check
Check throw direction, velocity, case manufacturer zones, and final layout.
Field solution
Reorient or relocate devices with design approval; rebalance.
Prevent it next time
Coordinate diffuser pattern with refrigeration case plan.
Stop / escalate
Stop if airflow causes case performance problems.
Condensation · Cold rooms8. Penetration through cooler wall is unsealed
Open
8. Penetration through cooler wall is unsealed
What to check
Inspect vapor barrier, sleeve, insulation, and panel damage.
Field solution
Install approved insulated sleeve/seal system; restore vapor barrier continuously.
Prevent it next time
Coordinate and sleeve all cooler penetrations before equipment set.
Stop / escalate
Stop if panel structural or sanitary requirements are unclear.
Sanitation · Food prep9. Duct debris falls over food-prep area during install
Open
9. Duct debris falls over food-prep area during install
What to check
Check containment, cleaning, and work-zone separation.
Field solution
Stop work; isolate area; clean surfaces; use caps and controlled cutting away from food areas.
Prevent it next time
Maintain capped duct and sanitation containment in food zones.
Stop / escalate
Stop if occupied food handling cannot be protected.
Hangers · Grease duct10. Grease duct support is attached to light ceiling framing
Open
10. Grease duct support is attached to light ceiling framing
What to check
Check structural load path and listed support requirements.
Field solution
Install dedicated supports to approved structure; remove ceiling-frame load.
Prevent it next time
Lay out structural supports before duct delivery.
Stop / escalate
Stop if support capacity is unknown.
Equipment · Unit coolers11. Supply duct blocks evaporator coil service clearance
Open
11. Supply duct blocks evaporator coil service clearance
What to check
Check coil pull, fan access, drain pan, and valve access.
Field solution
Relocate duct/supports or revise transition; preserve manufacturer service envelope.
Prevent it next time
Mark refrigeration equipment access zones during coordination.
Stop / escalate
Stop if service cannot be performed.
Controls · Smoke/fire dampers12. Damper actuator is inaccessible above freezer ceiling
Open
12. Damper actuator is inaccessible above freezer ceiling
What to check
Check access from warm side, ceiling construction, and listed assembly.
Field solution
Provide approved access or relocate actuator side if listing permits.
Prevent it next time
Coordinate actuator side before installing damper.
Stop / escalate
Stop closure until access is resolved.
Testing · Grease duct13. Welded grease duct has pinhole leaks
Open
13. Welded grease duct has pinhole leaks
What to check
Inspect weld continuity, corners, transitions, and access-door frames.
Field solution
Have qualified welder repair; inspect and retest per project requirements.
Prevent it next time
Use fit-up checks and staged weld inspection.
Stop / escalate
Stop concealment/fire wrap until welds pass.
Insulation · Cold duct14. Hanger compresses insulation and creates condensation point
Open
14. Hanger compresses insulation and creates condensation point
What to check
Check shield/saddle width and vapor jacket damage.
Field solution
Install proper insulation shield; repair insulation/vapor barrier; adjust support.
Prevent it next time
Include insulated outside dimension in support design.
Stop / escalate
Stop if moisture has entered insulation.
Commissioning · Store pressure15. Building is strongly negative after exhaust startup
Open
15. Building is strongly negative after exhaust startup
What to check
Check exhaust, MUA, outside-air dampers, door pressure, and control interlocks.
Field solution
Correct MUA operation, damper position, and balance with commissioning team.
Prevent it next time
Test exhaust and MUA together before opening.
Stop / escalate
Stop if negative pressure affects doors, combustion, or hood capture.
Check
- Current approved drawings and submittals
- Actual field dimensions and access
- Support, joint, equipment, and life-safety requirements
- Whether the correction changes design intent or another trade's work
Warnings
- Do not solve coordination problems by crushing, stretching, or forcing duct and equipment.
- Do not bury access, dampers, controls, filters, coils, cleanouts, or service panels.
- Do not treat lift, rigging, welding, refrigerant, gas, electrical, structural, or life-safety work as apprentice-only work.
Stop and ask
- Stop when the correction changes route, size, pressure class, listed assembly, equipment connection, structure, life-safety function, or another trade's approved work.