Expert HVAC Services

Offering Manual J, Manual S, Full Pack (J, D, S) and RHEIA System Design

Comfort by Design – Balanced Airflow, No Guesswork.

We believe comfort should be intentional- not something adjusted after installation.

With nearly a decade of industry experience, Above Grade specializes in HVAC system design, focusing on room-by-room airflow, thoughtful duct layout, and balanced RHEIA air distribution. Every project begins with detailed load calculations and ends with a clear, practical plan your contractor can confidently install.

We don't sell equipment and we don't perform installations. That independence allows every design decision to be made with one goal in mind: a home that feels comfortable, quiet, and consistent from the day you move in.

Whether you're building new or renovating, your comfort starts with good design.

Services We Offer

We provide Manual J, Manual S, and Manual D based on the procedures in the ACCA Manuals. Above Grade also specializes in RHEIA airflow distribution.

Manual J Only

The First Step to a Perfectly Sized HVAC System

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Manual J & S

Exact Loads. Optimized Equipment. Year-Round Comfort.

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Full Pack Manuals

The Complete Path to Comfort, Efficiency, and Performance.

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RHEIA

Air Distribution Design

Learn About RHEIA Systems

Trusted by Industry Experts

“I have had the pleasure of quality controlling Sean DeGrande’s work for going on 5 years. His work and attention to detail is refreshing especially in an industry where things can be rushed and easily overlooked. He is thorough in his designs and has surprised me with extra layers of well thought-out detail in his final reports that is unseen compared to many designers. I strongly recommend using Sean DeGrande as your preferred residential HVAC J, S, D and Rheia designer.”

Stephen Platka

Senior Design Engineer & Trainer at Rheia

**DISCLAIMER**

Above Grade HVAC Design offers independent residential HVAC design and airflow planning services. We are not a licensed mechanical contractor and do not install or supply HVAC equipment.
System performance depends on accurate construction practices, installation quality, and adherence to provided design specifications. Any deviations from the design may impact system performance and are outside our control.
It is the responsibility of the installing contractor to verify measurements, confirm field conditions, and ensure compliance with applicable building codes.