HVAC Load Calculation Software: 5 Best Software Solutions To Calculate HVAC Load

The heating, ventilation, and cooling systems, when installed in a house, clean the air and improve its quality. Also, it provides warm or cool air depending on the climate’s needs. 

Many people planning to get an HVAC system to assume that they are simply installing a new one or replacing an older HVAC system.

Well, let’s clarify that the assumption is wrong.

You can’t pick a random HVAC system and install it in your house. If done, it will refrain from giving a good performance and energy efficiency and lasts only for a short time. 

To choose the ideal HVAC system, HVAC load calculations must be done, and if it is done manually, it consumes immense effort and time. This is where the HVAC load calculation software steps in.

If you are an HVAC business owner looking for the best HVAC Load Calculation Software, this article has your back. We have listed the five Best Software Solutions To Calculate HVAC Load. Without any ado, now let’s check them out.

What is HVAC Load Calculation Software?

First, understand that the HVAC load calculation is a mathematical process that considers multiple aspects of a house to determine the best size, application, and style of the HVAC system. This calculation ensures maximum energy efficiency while enhancing the home’s comfort. 

Those days, load calculations were done manually. But with technological advancements, HVAC technicians can quickly calculate the HVAC loads using robust load calculation software. The HVAC load software or calculator determines how much heating and cooling a residential building needs, based on its design and specifications. 

HVAC load calculations consider several specific areas in your house to find the right-sized system:

  • Total square footage of the property
  • Number of windows, doors, and entryways
  • Number of floors & living space
  • What exact landscaping outside your house can block the sun from entering the house?
  • The duct work condition, size of ductwork, and the vent systems
  • Window shades, blinds, or other household window treatments used to keep the sun out

Importance of HVAC Load Calculation Software

Apart from delivering accurate HVAC heat load calculation or cooling load calculation, the HVAC load calculator also offers other benefits.

This software helps you to pick the right-sized HVAC system that will bring high comfort and efficiency to your home. So, when you invest in the right-sized systems, it consumes less energy every day meanwhile producing excellent results. It also impacts your energy bills and helps you save more. 

HVAC load calculations also allow HVAC service providers to detect any critical issues priorly and fix them before it affects your overall energy saving and comfort.  

US Energy Information Administration (EIA) shows that heating and cooling systems are the largest residential electricity uses. If the right size equipment is not installed, it may easily reflect on your energy bills. 

So it is crucial to calculate the load properly before installing the HVAC systems. Otherwise, you will end up shedding your cash for a larger unit or smaller unit and face issues over time.

Detail Review of Top 5 Software to Calculate HVAC Load

1. HeatCAD

HeatCAD is a drawing-based software that delivers fast and accurate calculations for residential heating and cooling loads. 

This robust HeatCAD HVAC load calculation software comes in two editions: Professional Edition and MJ8. 

The Professional Edition of HeatCAD supports ASHRAE and CSA residential heat loss calculations. Meanwhile, the MJ8 edition supports ACCA Approved Manual J calculations for residential cooling and heating loads.

Apart from delivering HVAC load calculations, this software gives advanced design features, including integrated load calculations, 3D CAD views, and automatic detection of unheated surfaces.

Professional edition:

Creates floorplan drawings quickly using the predefined rooms, doors, windows, and other objects. 

You can also import an existing AutoCAD, PDF, or scanned drawings to use as a template.

Calculates automated heat loss as you draw using ASHRAE and CSA residential heat loss calculations

Here, the files are compatible with LoopCAD® for radiant designs and 3D drawing views. 

MJ8 Edition:

This includes all features in Professional Edition, plus the ACCA-Approved Manual J residential and cooling load calculations.

Some notable features of both software editions are

  • Performs room-by-room residential heating and cooling load calculations while you draw.
  • Enhanced New Project Wizard makes the project setup easier.
  • It is easy to learn, and no previous CAD experience is required. 
  • Free program updates and technical support are available with the active subscription.
  • You can get an online help file and a PDF user’s guide.


If you want to close more sales, consider investing in the right HVAC load calculator and give the best results. 

Energy Design Systems (EDS), an HVAC software company, delivers two amazing tools: the HVAC load calculator and the Home Auditor. 

The EDS HVAC load calculator is among the easiest and the most accurate residential heat loss and heat gain load calculators in the market. 

This software helps find the best size, application, and type of HVAC system for a house in under five minutes. This is done by utilizing the data from Zillow, Google Earth, and other real estate databases combined with a complex series of algorithms and equations. 

With this HVAC load calculator, you can get accurate load calculations. Thus, you can minimize operating and equipment costs, enhance equipment longevity and improve the health and comfort of your house by installing the right equipment.

Some notable features of this load calculation software are

  • User-friendly interface: The load calculations are displayed in a clear format.
  • Helps transform your HVAC business: Allows simplifying the HVAC business workflow.
  • Software update: Get all software upgrades for free with your subscription.
  • Customer support: You get 24/7 customer and technical support. 
  • Secure and reliable website: The website has 99.96% uptime. So you can get accurate HVAC load calculations anytime, anywhere using the website.

3. ServiceTitan

ServiceTitan has provided reliable solutions to level up the HVAC business. Over 100,000 professionals currently trust it as it has incorporated the best practices to streamline the business tasks in the field service industry.  

It consists of various software to help smooth running of HVAC business, and its free HVAC load calculator software is one such thing. 

ServiceTitan HVAC Calculator is designed to help you find the ideal HVAC equipment for your house. This free online calculator quickly determines the amount of cooling and heating a residential building needs concerning its design and specifications. 

The load calculations indicate the amount of BTUs required for sufficient heating and cooling. 

How does the ServiceTitan HVAC Calculator work?

You can get an estimated HVAC load calculation by choosing the multiple options in the HVAC calculator tool. 

The requirements include

  • Where is the house located?
  • What is the square footage? (SQFT)
  • What is the ceiling height? (FT)
  • How would you rate the insulation?
  • How much sunlight does it get?
  • How many windows does it have?
  • Are the doors and windows well sealed?
  • Does the house have these rooms? (Glassed-in room & Kitchen)
  • How many people live there?
  • Extra Device Heat Wattage (W)

When you enter the above requirements correctly, you can get an idea about the calculation. To get the accurate HVAC load value, one must adopt the Manual J residential calculation technique designed by ACCA – Air Conditioning Contractors of America. Though this method requires time, energy, and money, the result is worth it.

4. Area Cooling Solutions

Area Cooling Solutions, an HVAC and refrigeration company, consistently provides smart solutions for a green future. With over 10 years of experience in inverter driver applications, remote control, and preventive maintenance, this company also offers robust calculation software. 

This HVAC load calculation software allows you to select their products based on your needs. You can quickly choose your ideal equipment from compressors or condensing units based on the capacity or a specific product line. So this simplifies the selection process and helps you find your exact need. 

How does the HVAC load calculation software work here?

Step 1: Select search for compressors or condensing units

There are many HVAC equipment listed on the website. Click on the search option and look for your ideal equipment. You will find the details for each product.

Step 2: Search forms based on Capacity or Model/Unit

You can choose the ideal equipment and then look for the forms based on capacity or model.

Step 3: Fill in the chosen form

Enter your requirements given in the form. For example, you can enter the condensing unit, application name, and capacity based on your need.

Step 4: List of results

The calculator will calculate based on your requirements and list a set of equipment or products. You can now do basic research and choose the ideal HVAC equipment.

5. LoadCalc

LoadCalc is a load calculation software designed based on Manual J calculation. Since the LoadCalc HVAC load calculator uses Manual J calculation, you can get a decent estimate. This easy and quick load calculation software calculates the amount of heating and cooling British Thermal Unit for the whole house or room by room load.

How to use this HVAC load calculator?

Step 1: Select the state and city given on the dashboard. Once the location is chosen, you will get directed to the load calculation page.

Step 2: Select the types of windows, walls, ceiling, floors, doors, etc., for the structure. 

Step 3: Select the basement walls and floors.

Step 4: Choose the shading factors such as window height, overhang, and window top to overhang.

Step 5: Now select the design conditions

After choosing these options, click on the “Go to next step” button. A different page will open where you must add the sq. ft associated with the structure choices. 

You will find a “Help” button in the menu near the middle of the page. Click on it to learn the further instructions and get the HVAC load calculation value. 

Frequently Asked Questions

Why is load calculation necessary?

Load calculation is essential to install the ideal HVAC systems in your house and maintain efficiency, keep the temperature constant, improve comfort, and lower energy bills. So overall, load calculation is essential to acquire the right HVAC system as choosing a random one can either make or break the system.

What is the Manual J calculation?

It’s a formula that helps in determining the HVAC capacity of a building. It is also called HVAC load calculation since it defines the size of the HVAC equipment needed to cool and heat a building. This calculation is complex, and many HVAC professionals seek help from Manual J calculators to draw estimates for their clients.

How do you calculate HVAC load?

To calculate HVAC load, you can use this formula,

  • (House surface in square feet) x (height of the ceiling) + (Number of occupants) x 100 BTU + (Number of exterior doors) x 1,000 BTU + (Number of windows) x 1,000 BTU
The sum of these values is your final HVAC load value.

Can anyone do the Manual J calculation?

Yes, anyone can do the manual J calculation and get the accurate sizing of the space for installing an HVAC system. But it is a tiring process. But you can ease things by investing in the best HVAC load calculation software. However, this can be unnecessary if you are paying the Manual J program for a single project. So you can seek help from your HVAC technicians.


If the HVAC load calculations are not carried out before installing the HVAC system in the house, you are likely to install an HVAC system of an improper size. 

So HVAC load calculation is important. If the HVAC system is larger, it will lead to high running costs. if it is smaller, the system will constantly run to fulfill the cooling needs instead of maintaining a cool temperature. Also, it shortens the lifespan of the system when often overburdened to cool a huge space. 

To get quick and accurate results, investing in the best HVAC load calculation software is recommended. We hope that you pick an ideal software from the above-given list.

Gaurang Bhatt

Written by

Gaurang Bhatt

Guarang Bhatt has 15+ years of experience in serving different businesses through advanced technology-based solutions. He has special expertise in Saas-based software solutions and solving complex business problems and challenges. Passionate about HVAC software solutions, he shares his knowledge and learnings on HVACsoftware.com.