ACCA Manual S
Verifying ACCA Manual S Procedures
Why is proper equipment sizing important?
Achieving occupant satisfaction is the principal goal of any HVAC design. Occupant satisfaction is maximized when the heating and cooling equipment are the correct type and size to meet
the capacity requirements from the Manual J load
calculation. For residential equipment selections, ACCA Manual S is the only procedure recognized by the American National Standards Institute (ANSI).
If the Manual J load calculation is done then the next step is to select the equipment that will deliver the necessary heating and cooling
Key items when selecting equipment
Design Conditions: Do the design conditions fall within the minimum standards of Manual J8
OEM’s Performance Data: The equipment manufacturer’s performance parameters match the design parameter.
Equipment Performance:
- Was the sensible heat ratio calculated?
- Was the SHR used to find the proper air flow?
- Is the total heating capacity of the equipment equal to or less than 140% for single stage equipment?
- Is the total cooling capacity within 6000 BTU’s of design?
- Does the “Sensible” and/or “Latent” capacities of the equipment meet the load’s requirements
- If utilizing a heat pump in a very cold climate does the total cooling capacity exceed 125%
of cooling design
Auxiliary Heat:
- Is the auxiliary adequate to meet load requirements?
