Preloader logo

Phoenix Arizona Residential Manual “J” Load Calculations

Residential Manual “J” Load Calculations

Energy Star, the Department of Energy, the Environment Protection Agency and all equipment manufactures state that the proper method for equipment sizing is to perform a HVAC load calculation, also known as a Manual J Load Calculation. This is the only way to ensure that the heating and cooling system is the correct size for your home. In the past, contractors used the square feet of a building to size equipment. As you can imagine, this led to many incorrect size systems being installed. Even minor factors such as the exposure or the amount of attic insulation in a house can alter to heating and cooling capacity required.

At JL Finley Construction, we utilize accredited Manual J Eighth Edition load calculation software. This software verifies many factors about your dwelling including the indoor design temperature, building construction materials, insulation R value, type and size of windows, sliding patio doors and sky lights, roof covering and number of people inhabiting the space.

The software will calculate all the factors and provide the sensible and latent capacity required to heat and cool the home. This capacity is then used to match a heating and cooling system which will produce the same capacity within tolerance.  This important match-up is completed by utilizing the Manual-S requirements.  Once the equipment is selected, the duct work can now be designed using specific factors given to us by equipment manufacture’s fan rating tables and pressure drop charts in which we can apply to your new duct design using Manual-D requirements.


  • Accepted file types: jpg, png, pdf.

Why do I need a Manual “J” Load Calculation?

Performing a load calculation is the single most important factor when designing a heating and cooling system. Installing a system which provides the correct capacity is vital to realize the maximum efficiency of your new system.

Installing a system that is undersized will require the system to run continually, struggling to meet the temperature set point. The consequence of this can be an uncomfortable environment, increased operating costs and can lead to unexpected repair costs.

An over-sized system will satisfy the temperature setting quickly then cycle off. This does not allow the system to operate long enough to effectively remove the humidity from the home and will require the system to cycle excessively during the day, driving up electricity bills. The usually results in a cool damp house.

Load calculations are required by most municipality building departments for new construction and room additions. At JL Finley we perform load calculations on all installations so you can be assured that the system we install will be the correct size and operate at the stated energy efficiency. This service can also be provided to individuals who are building a new home or room addition.  Along with your Manual J S and D forms we will provide your equipment submittal forms as supporting documentation to help stream line the permitting process.


How does the Manual “J” Load Calculation process work?

  1. You purchase the Manual J, Manual S, and Manual D service.
  2. Next you send us a file with the .pdf plans of the property by uploading here on this page.
  3. Next, Our licensed HVAC professionals produce your complete design.
  4. Then we e-mail you back the comprehensive Manual J, Manual S, and Manual D based on the information you provided us.
  5. Finally, if you decide to use JL FINLEY CONSTRUCTION for the complete installation of your equipment and ductwork, we will credit you back 50% off of the total design cost. (Phoenix and surrounding cities only)
William KohlmannMichael Joseph KolterHoustin EngstromLinda PirklJonathan WilliamsPaulette Kleinschmidt
Service second to none! I was lucky enough to have met Josh and got his business card about 48hrs prior to my AC going out. It was the Thursday before Labor Day and he took my call, he dropped everything to hop on my 110* roof to get my AC back up and running practically immediately, but it stopped working again and it took me until about 4pm on Friday before Labor Day Weekend when I gave Josh the green light to replace the unit (mind you the house got 95* at night) and wouldn't you know it - Josh moved mountains for me and had a crane out front by 8am Sat morning to haul the new AC unit on my roof. He sent me before and after photos, was always in contact, and checked in often to make sure everything was ok. The whole experience was very smooth and I will always recommend and use the very professional JL Finley Construction for any AC/Heater needs.
William Kohlmann
1st rate quality and service, I had a new rooftop HVAC unit and air handler installed by JL Finley Construction along with a water softener and a RO water system, and I am 100% pleased. I got 3 quotes and Josh was very fairly priced for the amount and quality of work that he performed. Always on time and kept me up to date on all the progress of the work being done. Answered all my questions and discussed all the options that were available to me plus the work on the job site was extremely neat and tidy.
Michael Joseph Kolter
Great worksmanship, knowledge, and pricing! Highly recommend JL Finely for any of your hvac needs. Josh prioritizes customer service and will not disappoint!
Houstin Engstrom
Excellent experience! I recently had a new rooftop HVAC unit installed by JL Finley Construction. Josh was very professional and able to provide clear explanations of several options appropriate to my situation. Once the unit was selected, the project was completed in an efficient and professional manner. Josh also offered to absorb the additional cost of a larger crane, which was required to place the unit (and had not been included in the initial estimate). His attention to detail, knowledge, experience, and respectful manner were much appreciated.
Linda Pirkl
I received Josh’s info through a long line referrals. Customer service is clearly important with this company. I had them install a new AC unit and re-roof at the same time. Top notch installation and attention to details.
Jonathan Williams
I recently purchased a condo and hired JL Finley to service my AC system. He was very detailed in his explanation, as he was when he completed the work that was needed! It means everything to find a contractor who is honest and does the work needed for a fair price! Mr. Finley did just that! He explained everything in a way I could understand! Thank you. . .I couldn't be happier!
Paulette Kleinschmidt

Schedule a Free Estimate

  • Accepted file types: jpg, png, pdf.