Paint Shop Planning—From Floor Plan to First Spray | Article 18 of 28
How to Compare Paint-Booth Proposals
The lowest number on the last page is not always the lowest-cost proposal.
Three paint-booth vendors can receive the same request and return three proposals that look similar at first glance. Each may show a booth, exhaust fan, lights, doors, controls, and a final price.
Look closer, and the differences begin to appear. One includes an air-makeup unit. Another assumes the owner will supply replacement air. One includes exhaust ductwork to the roof. Another stops at the booth outlet. One includes startup and testing. Another considers its job finished when the equipment arrives.
Comparing only the total price can reward the proposal that leaves out the most work. A proper evaluation brings every proposal to a common scope, verifies performance, identifies assumptions, assigns missing costs, and considers the system’s operating life.
The workman’s rule: Before comparing prices, make sure everyone is selling the same job.
1. Confirm That Every Vendor Received the Same Information
Begin by confirming that every bidder received the same specification, drawings, product data, coating information, addenda, and answers to questions.
Common bid information should include
- Owner’s Project Requirements
- Equipment specification
- Building and site drawings
- Product sizes, weights, and production rates
- Coating technical and safety data
- Utility information
- Required scope and responsibility matrix
- Requested proposal format
- Required schedule
- All issued addenda
If one vendor priced an earlier drawing or missed an addendum, correct the problem before beginning the commercial comparison.
2. Check the Proposal for Completeness
A polished cover and a convincing sales letter do not prove that the proposal is complete. Check every required proposal section.
- Scope of supply
- Equipment description
- Performance data
- Utility requirements
- Codes and listings
- Preliminary layout drawing
- Control sequence
- Responsibility matrix
- Installation scope
- Testing and commissioning
- Training
- Documentation
- Schedule
- Itemized price
- Options and alternates
- Deviations, assumptions, and exclusions
- Warranty and service
Record every missing item. Do not assume silence means compliance.
3. Build a Bid-Leveling Sheet
A bid-leveling sheet places each vendor’s proposal into the same categories. This allows the owner to compare scope, performance, price, and risk side by side.
Included
The vendor clearly includes the requirement in its base price.
Excluded
The vendor clearly states that the requirement is not included.
Exception or alternate
The vendor proposes a different solution or does not meet the requirement exactly.
Not stated
The proposal does not provide enough information to determine compliance.
“Not stated” should never be converted into “included” without written clarification from the vendor.
4. Compare the Physical Equipment
Confirm that every proposed system provides the required working space and access.
Compare:
- Internal usable length, width, and height
- External equipment dimensions
- Door size and arrangement
- Personnel-door locations
- Product clearances
- Floor, pit, or raised-platform construction
- Wall and ceiling construction
- Panel thickness and finish
- Window and lighting arrangement
- Filter access
- Motor and fan service access
- Equipment location within the building
A booth that has the correct outside dimensions may not provide the same usable work area after plenums, filters, lights, and internal structures are included.
5. Compare Airflow Performance
Airflow should be compared at the complete operating condition, not by fan horsepower or free-air fan rating.
Evaluate:
- Airflow pattern
- Required operating CFM
- Air velocity and measurement method
- Calculated system static pressure
- Fan operating point
- Clean-filter pressure drop
- Loaded-filter pressure drop
- Exhaust-duct resistance
- Replacement-air volume
- Booth and building pressure control
- Airflow alarms and interlocks
A larger fan motor does not automatically mean better booth performance. The fan, duct, filters, air-makeup system, and controls must operate as a balanced system.
If a vendor has not included exhaust-duct resistance, filter loading, or replacement air in its calculation, the quoted airflow may not represent field performance.
6. Compare the Air-Makeup System
A booth can exhaust thousands of cubic feet of air per minute. That air must be intentionally replaced.
Determine whether each proposal includes:
- Air-makeup equipment
- Heating capacity
- Supply fan and motor
- Intake hood and weather protection
- Supply filters
- Roof curb or structural support
- Supply ductwork
- Temperature controls
- Pressure controls
- Burner and fuel train
- Electrical and gas requirements
- Freeze protection
- Startup and balancing
If an air-makeup system is excluded, assign the estimated cost of providing one before comparing the proposal total.
7. Compare Filtration
Filter cost, availability, efficiency, holding capacity, pressure drop, and replacement method affect both finish quality and operating expense.
Compare:
- Intake-filter type
- Ceiling-filter type
- Exhaust-filter type
- Filter dimensions and quantities
- Initial pressure drop
- Recommended final pressure drop
- Holding capacity
- Replacement access
- Expected service interval
- Annual replacement cost
- Local availability
- Proprietary versus standard sizes
An inexpensive booth using costly proprietary filters may become the more expensive system after a few years.
8. Compare Lighting, Visibility, and Working Conditions
Count fixtures, but also evaluate how the booth will illuminate actual working surfaces.
Consider:
- Fixture location and angle
- Light level at the product
- Lighting uniformity
- Color-rendering quality
- Glare and shadows
- Fixture listing and approved installation
- Access for cleaning and service
- Replacement-lamp or component availability
- Emergency lighting
Operators should review booth layouts. The people who prepare, spray, inspect, and maintain the product may notice practical problems that a purchasing spreadsheet will miss.
9. Compare Heating and Curing Capability
For a heated booth or oven, compare performance using part-metal temperature and representative production—not just maximum air temperature.
Evaluate:
- Burner or heater capacity
- Direct-fired, indirect-fired, electric, infrared, or combination heating
- Temperature range
- Temperature uniformity
- Heat-up and recovery time
- Maximum product load
- Required part-metal temperature
- Time at temperature
- Maximum volatile load
- Purge sequence
- Cooling requirements
- Product-profiling test
If one proposal is based on an empty enclosure and another is sized for the heaviest production load, the equipment is not equivalent.
10. Compare Controls and Safety Interlocks
The control system determines how the equipment starts, operates, responds to faults, shuts down, and returns to service.
Compare:
- Control-panel construction
- Programmable controller and operator interface
- Airflow-proving method
- Filter and pressure alarms
- Burner safety controls
- Spray-equipment interlocks
- Electrostatic-system interlocks
- Emergency-stop functions
- Fire-system interface
- Power-failure response
- Alarm history and diagnostics
- Remote-support capability
- Owner access to programs and passwords
- Available spare input and output capacity
Require each vendor to provide or confirm a written sequence of operation. Two control systems with similar panels may perform very differently.
11. Compare Codes, Listings, and Approvals
Review the codes, standards, listings, and permit assumptions identified by each vendor.
Determine:
- Which code editions were used
- What equipment listings are provided
- Who prepares permit drawings
- Who submits plans
- Who answers plan-review comments
- Whether hazardous-location requirements are included
- Whether fire protection is included
- Whether insurer requirements were considered
- What happens if the Authority Having Jurisdiction requires changes
A proposal that says “designed to meet applicable codes” without identifying the code basis or responsibility for approval may leave significant uncertainty.
12. Compare the Responsibility Matrix
Place each vendor’s responsibility matrix beside the project specification. Identify every difference.
Pay particular attention to:
- Permitting and engineering
- Freight and unloading
- Rigging and equipment assembly
- Foundations and pits
- Roof and wall penetrations
- Structural supports
- Exhaust and supply ductwork
- Electrical power and controls
- Gas and compressed-air piping
- Fire-protection work
- Startup and commissioning
- Testing and balancing
- Training and documentation
If a task belongs to the owner or another contractor, assign an estimated cost and schedule responsibility before comparing the proposals.
13. Read Every Exclusion
Exclusions often reveal the largest differences between proposals.
Common exclusions include:
- Freight and taxes
- Permits
- Stamped engineering drawings
- Unloading and rigging
- Installation labor
- Electrical feeders and disconnects
- Gas piping and regulators
- Compressed-air connections
- Roof curbs and penetrations
- Fire suppression
- Startup travel
- Testing and balancing
- Operator training
- Filters and consumables
Read the exclusions before admiring the price. That is where inexpensive proposals often explain why they are inexpensive.
14. Challenge Assumptions
An assumption can affect equipment size, performance, price, or responsibility. Require written clarification of every material assumption.
Examples include:
- The building has adequate electrical capacity.
- The existing gas service can supply the burner.
- The owner will provide replacement air.
- The roof can support the equipment.
- No fire-suppression modification is required.
- The product enters at a stated temperature.
- The coating contains no more than a stated solvent load.
- Equipment can be unloaded beside the installation area.
- Installation will occur during normal working hours.
- No union, prevailing-wage, or special-site rules apply.
Replace unsupported assumptions with verified information wherever possible.
15. Identify Deviations and Exceptions
A deviation is not necessarily a defect. A vendor may offer a better arrangement or a standard design that meets the project’s intent differently.
Every deviation should identify:
- The specification requirement
- The proposed difference
- The reason for the change
- Effect on performance
- Effect on safety or approvals
- Effect on utilities
- Effect on maintenance
- Effect on schedule
- Effect on price
Silence is not compliance. Ask the vendor to state whether all unlisted requirements are included without exception.
16. Add Missing Scope to the Evaluated Price
Bid leveling requires more than making notes. Estimate the cost of missing items and add them to the proposal for comparison.
Quoted price
The vendor’s stated proposal total.
Scope adjustments
Estimated costs for missing equipment, work, freight, installation, testing, or required options.
Risk allowance
A reasonable allowance for unresolved assumptions or uncertain scope.
Evaluated price
The expected comparable project cost after scope and risk adjustments.
Keep the vendor’s quoted price separate from the owner’s evaluation adjustments. This preserves a clear audit trail.
17. Compare Installation Plans
Installation quality affects equipment performance. Review how each vendor proposes to unload, assemble, connect, test, and turn over the system.
Evaluate:
- Installer qualifications
- Site supervision
- Required owner labor
- Installation duration
- Shutdown requirements
- Rigging plan
- Site storage and weather protection
- Waste removal and cleanup
- Safety procedures
- Coordination with other trades
- Punch-list responsibility
A well-manufactured booth can perform poorly when assembled incorrectly, ducted carelessly, or connected without proper controls coordination.
18. Compare the Project Schedule
“Delivery in twelve weeks” may mean twelve weeks after drawing approval, deposit, permit approval, receipt of all technical information, or another event.
Require each proposal to identify:
- Proposal validity
- Required deposit or purchase order
- Engineering and drawing schedule
- Owner-review duration
- Permit responsibilities
- Fabrication lead time
- Shipment date
- Installation duration
- Startup date
- Commissioning and training duration
- Final documentation date
Identify long-lead components and conditions that can change the schedule.
19. Compare Commissioning and Acceptance
A proposal should state who will demonstrate performance and what instruments, procedures, and reports will be used.
Compare provisions for:
- Airflow measurement
- Booth and building pressure testing
- Filter pressure-drop readings
- Temperature-uniformity testing
- Product-temperature profiling
- Alarm and interlock testing
- Emergency-control testing
- Fire-system interface testing
- Representative production trial
- Finish-quality demonstration
- Written commissioning report
Verify whether commissioning travel, labor, test instruments, and repeat visits are included.
20. Compare Training and Documentation
Determine whether training is a brief equipment walk-around or a structured program for operators and maintenance personnel.
Compare:
- Training subjects
- Number and length of sessions
- Operator and maintenance training
- Maximum number of attendees
- Training materials
- Hands-on instruction
- Follow-up training
- Operating manuals
- Final as-built drawings
- Control-program backups
- Parts and maintenance lists
- Commissioning reports
Documentation should be a required deliverable tied to final acceptance and payment.
21. Compare Warranty, Parts, and Service
A production system must be supported after installation.
Evaluate:
- Warranty start date and duration
- Parts and labor coverage
- Travel coverage
- Warranty exclusions
- Required owner maintenance
- Technical-support availability
- Remote-diagnostic capability
- Local service technicians
- Normal and emergency response time
- Replacement-parts availability
- Proprietary components
- Recommended spare-parts package
Ask for references from customers operating similar equipment—not simply a list of the vendor’s largest customers.
22. Evaluate Operating Cost
Purchase price is only one part of total cost. A paint booth consumes filters, electricity, heat, compressed air, cleaning materials, maintenance labor, and replacement parts throughout its life.
Compare estimated:
- Fan electrical consumption
- Air-makeup heating cost
- Cure-cycle energy use
- Filter replacement cost
- Compressed-air consumption
- Cleaning and maintenance labor
- Spare-parts cost
- Expected equipment life
- Downtime risk
- Waste and transfer efficiency
Ask vendors to state the conditions and energy rates used for operating-cost calculations. A precise-looking number built on unrealistic assumptions is still unreliable.
23. Evaluate Production and Quality Risk
The least expensive equipment can become costly if it limits production or creates inconsistent finishes.
Consider:
- Can the system meet the required parts per hour?
- Can it handle the heaviest and largest products?
- Will airflow remain stable as filters load?
- Can the heating system cure the worst-case product?
- How quickly can filters and colors be changed?
- What happens when a critical component fails?
- Are replacement parts readily available?
- Can the system support planned expansion?
- Can maintenance personnel service it safely?
Assigning a risk rating helps keep important operational differences from disappearing behind the proposal price.
24. Use a Weighted Evaluation
Price should be important, but it should not be the only scored category. Develop the weighting before opening final commercial proposals.
Possible evaluation categories
- Technical compliance
- Process and finish capability
- Safety and code compliance
- Completeness of scope
- Evaluated project cost
- Operating cost
- Installation plan
- Schedule
- Commissioning and training
- Warranty and service
- Vendor experience and references
- Future flexibility
The scoring system does not replace judgment. It organizes judgment and creates a record of why the team selected one proposal.
25. Hold a Technical Clarification Meeting
Meet with each serious bidder before making the final selection. Use the same core question list for every vendor.
Ask the vendor to explain:
- How the system meets the production requirement
- How airflow and replacement air were calculated
- How the worst-case product will be cured
- What is excluded
- What assumptions remain unverified
- Who is responsible for each installation task
- How performance will be tested
- What support is available after startup
Record all clarifications and incorporate accepted answers into the final contract documents. A verbal promise made during a sales meeting is difficult to enforce later.
26. Check Vendor References Carefully
Contact customers with equipment similar in size, process, and complexity.
Ask:
- Did the vendor meet the promised schedule?
- Were there unexpected exclusions or change orders?
- Did the equipment meet production and quality requirements?
- Was installation well coordinated?
- Were startup and training effective?
- How quickly were problems corrected?
- Are replacement parts readily available?
- Would the customer select the vendor again?
Ask about problems as well as successes. Every substantial project encounters difficulties. The important question is how the vendor responded.
27. Issue a Final Scope Clarification
Before issuing a purchase order, prepare a final written scope clarification containing all accepted changes, options, answers, drawings, and commercial conditions.
The final agreement should establish:
- Complete scope of supply
- Accepted deviations and alternates
- Final responsibility matrix
- Performance guarantees
- Testing and acceptance requirements
- Project schedule
- Payment milestones
- Warranty terms
- Required documentation
- Change-order procedure
- Order of precedence among contract documents
Do not issue a purchase order containing only a vendor proposal number. Attach or clearly incorporate the specification, addenda, clarifications, responsibility matrix, accepted drawings, and final negotiated terms.
Questions to Ask Before Selecting a Vendor
- Are all proposals based on the same project information?
- Has every exclusion, assumption, and deviation been identified?
- What equipment and work must be added to create an equal scope?
- What is each proposal’s evaluated project cost?
- Can each system meet the worst-case production requirement?
- What are the estimated operating and maintenance costs?
- How will performance be demonstrated?
- Which vendor provides the strongest service and parts support?
- What risks remain unresolved?
- Is every final promise included in writing?
Knowledge Check
- Why should proposals be leveled before prices are compared?
- What does “not stated” mean on a bid-leveling sheet?
- Why should missing scope be added to the evaluated price?
- What costs belong in a life-cycle evaluation?
- Why should technical clarifications be incorporated into the contract?
- Why is the lowest quoted price not necessarily the lowest-cost proposal?
Planning and contractual notice: This article provides general educational information and is not engineering, legal, financial, insurance, procurement, or code-compliance advice. Proposal evaluations and purchase agreements should be reviewed by qualified technical, financial, legal, safety, and contracting professionals. Final requirements must reflect the actual process, locally adopted codes, permit conditions, equipment listings, insurer requirements, and decisions of the Authority Having Jurisdiction.
Next in the series: Article 19 of 28—Who Is Responsible for What?
The booth vendor, general contractor, electrician, mechanical contractor, fire-protection contractor, engineer, and owner may all touch the same project. Article 19 explains how to divide responsibilities clearly so that important work does not disappear into the gap between contracts.
