MEP Engineering for a 2,700 sq. ft. Dental Clinic in Arizona

Project Overview

The project involved converting an existing 2,700 sq. ft. space into a dental clinic, bringing specialized clinical equipment and new building systems into an existing facility.

The starting point was not straightforward. Information about the existing mechanical and electrical systems was limited, while the building's 200-amp electrical service was already operating close to its capacity.

The new clinic introduced dental chairs, imaging equipment, laboratory equipment, HVAC, lighting, and other specialized loads, creating a fundamental engineering question: How much could the existing building support, and how could a fully functional dental clinic be integrated without exceeding those limits?

The Challenges

Limited Existing Information

Existing equipment and building conditions were not fully documented. The first engineering challenge was establishing a reliable picture of the existing mechanical and electrical infrastructure.

Electrical Capacity at the Edge

The existing 200-amp service was already close to its calculated demand, leaving limited capacity for the clinic's specialized equipment and building systems.

Specialized Dental Loads

Dental operatories, imaging equipment, laboratory equipment, and other clinical systems introduced electrical and grounding requirements, creating an additional layer of electrical safety beyond a conventional commercial fit-out.

Physical Constraints

The existing two mechanical units could not satisfy the clinic's calculated requirements. Additional HVAC capacity was needed while working within the existing building and avoiding major roof penetrations.

Equipment Changed After Permit

The HVAC equipment ultimately procured by the contractor differed from the electrical assumptions used in the approved design, creating a new capacity constraint after permitting.

Replacing the equipment would have introduced additional cost and delay. The system therefore had to be re-evaluated and modified around the procured equipment.

ME Engineering Approach

Establishing the Existing Building's Design Basis

Available equipment information, site imagery, equipment capacities, and engineering analysis were used to reconstruct existing conditions and establish a workable basis for the new MEP design.

This provided the foundation for understanding the building's available mechanical and electrical capacity before introducing the requirements of the new dental clinic.

Adding HVAC Capacity Without Major Structural Changes

Load calculations showed that the existing two mechanical units could not satisfy the clinic's requirements.

Additional HVAC capacity was introduced through an AHU split-system configuration, providing the required conditioning while avoiding large new roof penetrations.

Making 200 Amps Work

Every connected load was evaluated against the existing electrical service.

When the plan reviewer required panel-level justification under full operating conditions, detailed load calculations and documented engineering assumptions were developed to demonstrate that the clinic could operate within the available service.

This allowed the specialized dental loads and building systems to be accommodated without exceeding the existing electrical capacity.

Engineering for Dental Operations

Dedicated electrical supplies were provided for dental chairs, panoramic imaging, X-ray equipment, laboratory equipment, displays, and other specialized loads.

Redundant grounding was incorporated for the dental chairs and imaging systems to meet their specific electrical requirements.

The electrical design was therefore shaped around the actual requirements of dental operations rather than treating the space as a conventional commercial fit-out.

Adapting When the Field Changed

After permitting, the contractor procured HVAC equipment with a higher electrical requirement than the approved design basis.

Instead of replacing the equipment, the mechanical system was re-evaluated and modified by removing one mini-split unit and introducing a dedicated exhaust fan in the mechanical room to manage heat generated by the compressor and vacuum equipment.