• ​​Manual D
  • Manual D Calculation
  • Manual J & D Calculations

* HVAC Design  * Manual D

*Duct Design

Professionally Prepared For You

Valid in All States in The US

Fully compliant with ACCA standards

Call US Now:  973-544-6800   or email us: info@HeatLoadUSA.com

Heat-Load USA

ACCA Manual J load calculation - Manual S - Manual J HVAC - Manual J Calculation Service - Heat Load Calculation - Residential Load Calculation - Manual J Services - What is a Manual J - manual j hvac residential load calculation

- load calculation - Manual N - Commercial load calculation = HVAC ENGINEERS - HVAC CONSULTANTS

- ACCA Manual N Commercial load calculation - Manual D - Manual D calculation - Manual J & D Calculations

​​Manual D is essentially a sizing exercise for residential ductwork.  Ductwork must be sized appropriately in order for the whole house to be able to be heated and cooled properly. 

The size of the home,  zip code, elevation, summer high & winter low temperatures, exposure to southern and western sun, room function, amount of windows, square feet of a room, which floor it is on and summer humidity levels  -  all play a function in determining the size and amount of ducts needed for a room.

That room facing west with big windows? It will need more cooling then the room facing north and with small windows.  Rooms with a lot of people – like family room need more cooling.  Rooms in basement actually need about ¼ of the heating and cooling of 1st floor.  And so it goes.  Don't just go by square feet. 

The square feet rule or the tons/square feet rule to size equipment or ductwork is only about 60% accurate. In some cases they can be 80% wrong. Do you want to build a home that is 60% right? Do you want to live in a home that is 80% wrong?   

Sizing the equipment, selecting the equipment and then sizing the ducts are all integral parts of a good HVAC design.  The HVAC industry is all about comfort.That is what we do and provide: Comfort.  Well, for human beings, comfort is dependent on three things:

1. Temperature in the home

2. Humidity in a home

3. Sound levels of an HVAC system

Here at HeatLoadUSA we go that extra step.  We design our system for what we call “occupant transparency”.  That is the end user/customer should not hear or feel the HVAC system. They should not even know it's on. The system should work quietly in the back ground. A properly designed system will keep all of the conditioned area comfortable for it’s occupants AND save the homeowner money – month after month. 

Temperatures will be comfortable, not only on the main level but also room by room bases and even on different floors.

Yes it can be done.  But it starts with a Quality HVAC Design.  

A good and well done Manual D is an key component to achieving customer comfort, safety, and efficiency.  Our Manual D designs provide you the following:

  • Load calculations for each room

  • CFM (volume of air) needed for each room

  • Size of furnace, heat pump, AC required to satisfy the home

  • Equipment Part numbers for: Furnace, Condenser, Coils and/or heat pump

  • Location of central heating/cooling equipment

  • Full duct layout showing each individual trunk, branch, register, vent and all ducts for each zone

  • Short and Long J1 Forms

  •  Summary load forms

  • List of trunks and branches showing length and materials needed

  • Plus more…..

Optional: Complete inventory list needed to purchase materials for the job. This is particularly useful for homeowners and DIYers


Why Choose Heat Load USA?

We are certified by ACCA.  Every 5-years we renew our ACCA Quality Install and Design certificate. Our most recent certificate is below. 


Unlike others, we are actual HVAC contractors.  Make sure the person doing your load calculations has live install experience, and is certified. Many have read about load calculation.  Reading about it and doing it are two different things.  You agree? 

We do this for a living. We install heating and cooling systems.  We install new ducts, and we do both residential and commercial work.  So rest assured, we understand you, your needs and we know where you are coming from.  This means we speak your language and we will take care of you. 

100% Approval Rate.  All of our Manual J, D & S work is guaranteed to pass local township ACCA-heat load related requirements, all over the US. Weather you are in Maine, Virginia Florida or California.  You must provide us the drawings and comply with other regulatory requirements.  We serve all of the USA. We can help you. 

Rapid Service. Our Standard turnaround 4-business days.  Next Day Service is also available

We are here to serve you, so feel free to call us any time:  973-544-6800        



What Do We Need In Order To Prepare Your Manual D?

  • Floor Plan for each floor (including basement if applicable)
  • Sq ft of Windows on each side, on each floor
  • Sq Ft of doors on each side, on each floor
  • How you want your ducts laid out - Ideally your rough sketch of the ducts
  • Address of property 
  • Any known insulation levels in the home
  • Location of equipment and ductwork  - Basement, Conditioned space, Attic Garage etc.  
  • If more then one system, we need to know the coverage area and location of each system
  • Email all these to info@HeatLoadUSA.com.  

We will respond right away, and review what you sent us. If we are good, we will send you an invoice via PayPal. Pay that invoice and we will deliver your report within 48 hours. ​

                         Questions?  Call Us:   973-544-6800
                       Email:  Info@HeatLoadUSA.com