Right-sized equipment, on paper first
Manual S: pick equipment that fits the load.
A Manual J tells you what the house needs. Manual S proves the equipment you want to install can deliver it at your design conditions, without being so large it short-cycles and leaves the house clammy.
What it is
Manual S checks a specific furnace, air handler, condenser or heat pump against the Manual J loads using the manufacturer’s expanded performance data, not the nameplate tonnage.
It keeps equipment inside ACCA’s sizing limits, so it can dehumidify properly and does not cost more to buy and run than it should.
When you need it
IRC Section M1401.3 names Manual S directly: equipment is to be sized in accordance with Manual S, based on the Manual J loads. Plan reviewers increasingly check that the model on the permit matches the loads on the report.
What we need from you
- Your Manual J, or we run it
- The equipment you are considering, or let us recommend
- Fuel type and any utility or rebate requirements
What you receive
- Equipment selection worksheet
- Capacity at design conditions versus the calculated load
- An equipment schedule for the plans, on request
“LoadCalcs did great on load calculation for us. They selected ERV, Dehumidifier and HVAC equipment and designed the duct system. Great service!”
Questions
Do I need a Manual S if I already have a Manual J?
If your jurisdiction follows the IRC, usually yes, because the code ties the two together. We can run Manual S against an existing Manual J.
Can you recommend equipment?
Yes. We do not sell equipment, so we have no reason to upsize. We will show you which models fit and why.
Do you prepare equipment schedules?
Yes. We provide manufacturer, model, size, airflow settings and electrical requirements formatted for your plan set.
Same-day quotes
Drop the plans. Get a quote today.
Drop in the plan set and pick your services. A designer replies with price and turnaround, usually within 30 minutes during business hours.