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HVAC load calculation · Dallas-Fort Worth and Texas
Manual J calculations for your permit.
The building department wants an HVAC load calculation before it approves the permit. Send us the plans and the window and insulation specs, and we send back a Manual J report ready to submit, with Manual S and D if your city asks for them.
What it is
How much heating and cooling each room needs.
A Manual J is a room by room heat gain and heat loss calculation that follows ACCA Manual J. We model the house in Wrightsoft from your plans: walls, ceilings, windows, which way the house faces, air leakage and where the ducts run. The result is the load of every room and of the whole house, in BTU per hour.
That number decides the size of the system. Without it, equipment gets picked by square feet per ton, and an oversized unit short cycles and leaves the house humid.
- MJManual J, loadsHeating and cooling load for each room and for the whole house.
- MSManual S, equipmentManufacturer data checked against those loads, so the unit you pick actually fits.
- MDManual D, ductsTrunk and branch sizes for the air each room needs.
Why the city asks for it
It's in the code most Texas cities build on.
Most Texas cities base their residential code on the International Residential Code. Section M1401.3 asks for heating and cooling equipment sized with ACCA Manual S, from loads calculated with ACCA Manual J. Section M1601.1 asks for duct systems sized with ACCA Manual D.
Which reports a building department wants with the permit depends on the city and on the edition of the code it adopted. Some take the Manual J alone. Others want J, D and S together. Tell us the city in your request and the estimate will say what we include.
New homes
Builders send the plan set and get the report back for plan review, one per plan, done the same way every time.
Additions and remodels
A new room or a new system changes the loads. Remodelers get a calculation for the house as it will be after the work.
Homeowners
Building your own house or adding on, and the permit office asked for a Manual J? Send us the plans directly. Your HVAC contractor installs from our report.
What we need
Plans and two sets of specs.
With these we can start. If something is missing, we ask before we model, so the numbers match the house you're building.
- PLNFloor plansWith elevations and sections if you have them. PDF works best.
- WINWindow specsU-factor and SHGC from the window schedule or the supplier quote.
- RInsulationR-values for walls, ceiling or attic and floors.
- ADRAddress and cityFor the local climate data, the way the house faces and what that city asks for.
Pricing and delivery
Starting prices for a permit report.
Starting prices up to 2,000 sq ft. Delivery counts in business days from complete plans and an accepted estimate. You pay once, when you accept the estimate. Your final price is in the estimate.
Manual J
- Room by room loads, permit-ready PDF
- +$0.06 per sq ft over 2,000
- Delivered in 2 to 3 business days
- 1 revision included
Manual J & S
- Loads plus equipment selection
- +$0.06 per sq ft over 2,000
- Delivered in 2 to 3 business days
- 1 revision included
HVAC Design Package
- Manual J, D and S in one PDF
- +$0.08 per sq ft over 2,000
- Delivered in 3 to 5 business days
- 1 revision included
Each additional system adds $150. Need it sooner? Rush delivery in 24 to 48 hours adds 30%.
How we work
From plans to permit in four steps.
- 01
Send your plans
Upload the floor plan and whatever specs you have. We'll ask for anything missing.
- 02
Get your estimate
We review the plans and send a fixed price with a delivery date before any work starts.
- 03
We model it
The house goes into Wrightsoft room by room to size every duct and unit.
- 04
Check and deliver
We check the design against ACCA, ANSI and ASHRAE methods and send the permit-ready PDF.
Permit questions
Before you send the plans.
Do I need a Manual J for my permit?
If your city builds on the International Residential Code, equipment has to be sized from a load calculation, and ACCA Manual J is the method the code names (section M1401.3). Many building departments ask to see the report with the permit application. Your plan reviewer can confirm what they want, or tell us the city and we'll say in the estimate what we include.
Is a Manual J enough, or do I need Manual D and S too?
It depends on the city. Some accept the Manual J alone, others want the full J, D and S. If you're not sure, ask for the HVAC Design Package and you'll have all three in one PDF.
What does permit-ready mean?
The report is ready to submit with your permit application. Approval is up to your local jurisdiction.
How long does it take?
Manual J and Manual J & S take 2 to 3 business days. The HVAC Design Package takes 3 to 5 business days. Days count from complete plans and an accepted estimate. Rush delivery in 24 to 48 hours adds 30%.
I'm a homeowner, not a builder. Can I order one?
Yes. Send the plans and the window and insulation specs the same way a builder would. AG3 does the design only; your HVAC contractor installs the system.
What if the plan reviewer asks for changes?
1 revision is included while the plans stay the same. If the plans change, the new version is quoted separately.
Do you work outside Dallas-Fort Worth?
Yes. We're based in Dallas-Fort Worth and do the design work online, so we take residential projects across Texas and the rest of the US.
Ready when you are
Let's size it right the first time.
Send your plans today and get an estimate back.