“Contractors prepare and perform successful projects when they follow best practices for product installation and consult with attorneys on any legal issues that may arise,” said Chuck White, vice president of regulatory affairs with the Plumbing-Heating-Cooling Contractors Association. 

Among the best practices, one theme runs through nearly all of them: documentation. Yes, it’s understandable that HVAC contractors who enjoy working with their hands don’t want to sit at a desk for hours at a time, ensuring all the paperwork is in order. But it’s proper documentation that will be a contractor’s saving grace should issues arise. 

“If it is not in writing, it becomes much harder to prove later,” said Trent Cotney, partner and construction team leader at Adams & Reese LLP. “The party with the best paper wins the day.” 

What Documents Matter in Lawsuits? 

All documentation is important, but Cotney noted the following typically appear as evidence in HVAC litigation: 

• Contracts 

• Load calculations 

• Photos 

• Service notes  

• Permits 

• Change orders 

• Warranty documents 

• Customer communications 

“Use a clear written contract and document the job from start to finish,” Cotney said. “Manage customer expectations in the field.” 

Here are a few ways proper documentation can prevent liability risks HVAC contractors commonly face.  

Bad System Design 

Cotney said lawsuits against HVAC contractors frequently involve system sizing, design, and installation. Whether it's mold claims, poor performance, or high utility bills, improper installations or designs create disputes for all involved. It only becomes worse if contractors don’t document what they’re doing or provide vague proposals or change orders.  

Contractors should treat documentation as a continuous quality-control and risk-management tool by tracking environmental data, commissioning reports, contract change logs, and employee-training records.  

Simply meeting code requirements isn’t enough, either. Code helps, says Cotney, but it should be the baseline standard contractors should aim to achieve. Documentation showing a contractor adhered to ANSI-recognized standards set by organizations like ACCA helps protect them from liability. 

“There are a variety of additional performance requirements ranging from manufacturer specifications to industry standards that also govern the work performed by HVAC contractors,” he said. 

White says contractors shouldn’t provide one-line quotes that say, “We will change your 3-ton air conditioner for xxx dollars.” He said contracts need to be specific as to what equipment is being used, including AHRI documentation showing the certified equipment performance, and itemize any required improvements. 

“Having before-and-after documented data shows the diligent efforts made to help the consumer,” said White. “Bad installation of high-efficiency equipment, or any equipment really, kills efficiency and can reduce the lifespan of equipment.” 

Guessing at Load Calculations 

A subset of bad system design is bad calculations. White said relying on existing equipment for sizing calculations instead of completing Manual J calculations is a quick way to land in hot water.  

“It is hard to know what has changed in an existing building,” he said.  

For instance, additions or alterations could change the total conditioned space, like insulation upgrades or replaced windows. In addition, the existing equipment itself could have been oversized or undersized, and using it as the basis would only continue the problem. 

Instead, contractors should complete ACCA Manual J calculations and document them. When possible, White said it’s beneficial to take measurements on existing equipment to try to locate and document deficiencies ahead of time. 

“Solutions can be built into projects in the proposal stage; clients may then make informed decisions to accept or reject those solutions,” White said.  

The same principles apply to other calculations as well, such as Manual S for equipment meeting calculated loads, and Manual D, which guides sizing for duct systems. In the end, load calculations and measured performance data prove a successful system installation.  

“Contractors are hired as the experts that consumers rely upon; it is far easier to get a good grade when you do your homework before the exam,” White said. 

Customer Refusals 

As mentioned above, customers who receive well-documented information about their existing systems can make informed decisions on the proposed solutions. Then again, maybe they decide against them.  

Issues can arise when a customer refuses ductwork, insulation, or other upgrades and solutions. If the contractor hasn’t noted this properly, it can escalate into a bigger problem should the system fail to function as intended. Improvements should be signed off by the client for acceptance or rejection.  

“If the client won’t agree to do what is needed to solve problems, don’t be afraid to listen to that little voice inside that says, ‘Don’t do this job,’” said White. “Consumers want performance but don’t remember promises or agreements to live with a lesser job to save money.” 

To put it simply, confirm any refusals in writing. 

“Identify the recommendation, explain the risk, and state that the customer declined,” Cotney said. 

Good documentation won’t prevent every dispute, but it can improve a contractor’s ability to defend their work should litigation arise.