### Why Load Calculations Matter
The most consequential decision in any HVAC installation is equipment sizing. Too large and the system short-cycles — it heats or cools the space quickly and shuts off before completing a full humidity-removal cycle, leaving the home feeling cold but clammy and wearing out equipment prematurely. Too small and the system runs continuously on extreme days without meeting the load. The only correct way to size HVAC equipment is with a Manual J load calculation.
Overview
### What Manual J Calculates
Manual J is the ACCA standard for residential heating and cooling loads. It accounts for your home's square footage and geometry, insulation levels in walls, ceiling and floor, window area and glass type, solar orientation, ceiling heights, infiltration rate, internal heat gains from occupants and appliances, and local design temperatures. In Los Angeles, the design cooling temperature for the San Fernando Valley (where temperatures regularly exceed 100°F) is meaningfully higher than for coastal areas like Culver City or Brentwood — proper load calculations account for these local differences.
### California Code Requirement
In California, a Manual J calculation is required for permit issuance on any new HVAC installation or replacement. Beyond the code requirement, it's simply the right way to select equipment. LC Heating & Air performs full Manual J calculations as part of every HVAC installation, using industry-standard software with accurate local climate data.
### Standalone Load Calculations
If you're gathering bids and want an independent sizing recommendation before committing to a contractor, we offer standalone load calculation services. We measure your home, calculate the heating and cooling loads, and provide a written sizing recommendation you can use to evaluate proposals from any contractor.
Our Service Benefits
Proper equipment sizing
The only way to correctly size HVAC equipment is with a load calculation. Square footage rules of thumb consistently oversize systems in mild climates like LA.
California code compliant
Manual J calculations are required for HVAC permit issuance in California. We provide compliant documentation for every installation.
Location-specific climate data
We use accurate local design temperatures for your specific LA neighborhood — Valley, coastal, and foothill locations have meaningfully different heat gain profiles.
Standalone service available
We perform standalone load calculations for homeowners gathering bids — independent sizing recommendation before any equipment commitment.
Load Calculation Cost in Los Angeles
Pricing ranges for common load calculation services. Your actual cost depends on equipment, complexity, and home configuration. We provide an exact written estimate before any work begins.
Manual J load calculation
Free with system installation
$200–$400
Complete home energy audit
$300–$600
Service calls start at $125. Prices include parts and labor unless noted. Financing available on equipment installations. Learn about financing →
What Los Angeles Homeowners Say
“Had LC install a mini split in our 1940s bungalow. The work was clean, the unit is incredibly quiet. Highly recommend.”
J
Jennifer L.Hollywood, CA
“Furnace was making a loud noise. LC diagnosed it quickly, cleaned and tuned the whole system, tested CO levels, explained everything clearly.”
K
Kevin A.Burbank, CA
“We converted our garage into an ADU and needed HVAC. LC installed a mini split — permits, electrical, everything. Our tenant loves it.”
C
Carlos M.Silver Lake, CA
Book Load Calculation today.
Get a fast, accurate estimate from our certified local technicians right now.
We measure your home's floor area, ceiling heights, window sizes and orientation, and assess insulation levels.
02
Data collection
We document wall construction, window glass type, infiltration characteristics, and any unusual heat gain sources.
03
Manual J calculation
We run the data through ACCA-approved software using local design temperatures for your specific neighborhood.
04
Written sizing report
You receive a written report with calculated heating and cooling loads and equipment sizing recommendations.
Customer Reviews
300+ verified reviews
5.0
Google Reviews196 reviews on Google
SM
Sharon Meoded
Los Angeles, CA
“Lior and his team installed an AC unit in my room that doesn’t have central AC and it works amazing! They were so professional and cleaned up fully after themselves. He kept me in the loop the entire process and when he came out prior to installing showed me step by step what they would be doing! Highly recommend ! Super professional”
Google Review
PW
Patricia Williams
Los Angeles, CA
“LC Heating and Air is a reliable, affordable solution for all your central air and heating needs. I am an out of town landlord and it can be difficult to find the assistance I need. LC Heating and Air took care of my tenants issues quickly and explained all issues before making necessary repairs. I will def use them again if need be!”
Google Review
NE
Naomi Eagleson
Los Angeles, CA
“I hired LC Heating & AC to replace the drain pumps in our Mitsubishi Mini Splits and clean the condenser and was pleased with the service. Leo was responsive, thorough, and professional. I chose this company based on the glowing reviews I read online and wasn't disappointed. My husband and I look forward to using our AC this summer!”
Google Review
OI
Osher Itzhaki
Los Angeles, CA
“Amazing service!! I called LC heating and air and was fortunate enough to have scheduled them for a same day appointment . Leo arrived on time and was super friendly, polite and fixed my ax in no time . The price was fair and he explained what further steps I shouted take to keep my ac unit running for more years Thank you LC!!!”
Google Review
JS
Justin Shapiro
West Hollywood, CA
“Great experience!!’ Leo came to my house in West Hollywood at 9pm !! I had an emergency, my ac stopped working out of no where i called LC heating and air from the phone call with the office to the time the tech came the service was just amazing. Leo came and had my ac running in no time. Thank you so much !! Highly recommended”
Google Review
GH
Greg Haroutunian
Los Angeles, CA
“Sunday morning discovered AC in the unit is not working, called everywhere, no one wanted to come the same day. LC Heating came the same day, fixed the problem which apparently wasn't easy to figure out. Very professional, calm and confident, pleasant to work with. Leo was the lead guy. Great experience, highly recommend it!”
Google Review
AV
Adam Valdies
Los Angeles, CA
“Leo and his team were amazing! I am so glad we called them to handle our AC/Heating issue. The problem was not clear at first and required substantial troubleshooting but Leo was extremely communicative and very professional throughout! He figured out the problem and we cannot thank him enough! Highly recommend!”
Google Review
LO
Leeyam Ohayon
Los Angeles, CA
“I called LC Heating & Air when my heating unit stopped working. He came quickly and fixed the problem fast. The technician was very kind and experienced. He explained the problem to me and gave me maintenance tips for the future. I definitely recommend LC Heating and Air if you're in need of these services.”
Google Review
AY
ariel. yona.
Los Angeles, CA
“Amazingly service me heater broke down and I was looking for a local company in my neighborhood. I found LC heating and air I can’t express in words how pleased I was with this company the owner Leo came out was very professional friendly and fixed my heater in no time !!! Highly recommended”
Google Review
KB
kevin benoit
Los Angeles, CA
“I cannot recommend this company more. They came, assess my issue and then ordered the right parts from the company and made an amazing install and transform my AC unit into a smart controlled AC unit which no Other HVAC company was able to do, or wanted to take the time that it took to do it”
Google Review
TY
Todd Yasuda
Los Angeles, CA
“Asher (LC Heating & Air) is the best, he kept me informed throughout the whole process. Everything he told me is exactly how things were done. I couldn’t have asked for a better person to work with. If you want to work with a reliable person and company, I would highly recommend him.”
Google Review
CK
claudia kleinschmidt
Los Angeles, CA
“Our AC was broken and had been dripping for a couple days. Once we called LC heating and air they sent out Asher to fix it immediately. He checked out the AC and fixed the problem on the spot. He was super professional and informative. Highly recommend Asher and the company!”
Google Review
DF
D Fan
Los Angeles, CA
“Leo is the absolute best! Had an emergency call and he came out right away in the early evening. Showed me how my units work and what the problem was. A few minutes later, it was fixed and working again! I cannot recommend this guy more highly. Call him and you'll be happy!”
Google Review
JM
Jamie Morgan
Los Angeles, CA
“LC Heating and AC is the best! I couldn’t recommend enough. It was a 100/10 experience. Helped me get to the bottom of repairing my AC that was very complicated and messed up by someone else. They are very professional and kind on top be being super knowledgeable.”
Google Review
DA
dan amiel
Los Angeles, CA
“Great service my heater stopped working out of the blue and we just had a new born I called lc heating and air they were the only ones that answered they came out and a hour my heater was up and running I couldn’t thank them enough . Highly recommended”
Google Review
YG
Yane G.
Los Angeles, CA
“Very helpful and very respectful. I called for a repair and was answered immediately, they were great in explaining what was going wrong and how they would fix it i was glad with there work and would definitely be calling them for any future repairs.”
Google Review
LA
Leetal Adelle Cohen
Los Angeles, CA
“We reached out to Leo and had a new HVAC system installed by him and his crew. Very happy with the results! Very professional, knowledgeable and patient. The whole process was very smooth, quick and clean. System works perfectly. Highly recommend”
Google Review
AM
Agam Mashiah
Los Angeles, CA
“I called lc heating to fix my heater in my house . We decided to replace the heater throughout the whole out process the customer service was great they were very communicative, professional and were very clean . Thank you again for the great job”
Google Review
CR
Charles Raffini
Los Angeles, CA
“HVAC system was leaking in the attic. Leo took my call late at night and came immediately. He stopped the leak and came back to make sure the system was working properly. Very responsive, good work and great value. Highly recommend them.”
Google Review
YY
yoav yerushalmi
Los Angeles, CA
“Scheduled an appointment very quickly for our HVAC unit that was having trouble cooling. Were very meticulous and clean. Helped idenitfy the issue and did a great job explaining what needs to be done and doing it. Highly recommended...”
Google Review
SM
Sharon Meoded
Los Angeles, CA
“Lior and his team installed an AC unit in my room that doesn’t have central AC and it works amazing! They were so professional and cleaned up fully after themselves. He kept me in the loop the entire process and when he came out prior to installing showed me step by step what they would be doing! Highly recommend ! Super professional”
Google Review
PW
Patricia Williams
Los Angeles, CA
“LC Heating and Air is a reliable, affordable solution for all your central air and heating needs. I am an out of town landlord and it can be difficult to find the assistance I need. LC Heating and Air took care of my tenants issues quickly and explained all issues before making necessary repairs. I will def use them again if need be!”
Google Review
NE
Naomi Eagleson
Los Angeles, CA
“I hired LC Heating & AC to replace the drain pumps in our Mitsubishi Mini Splits and clean the condenser and was pleased with the service. Leo was responsive, thorough, and professional. I chose this company based on the glowing reviews I read online and wasn't disappointed. My husband and I look forward to using our AC this summer!”
Google Review
OI
Osher Itzhaki
Los Angeles, CA
“Amazing service!! I called LC heating and air and was fortunate enough to have scheduled them for a same day appointment . Leo arrived on time and was super friendly, polite and fixed my ax in no time . The price was fair and he explained what further steps I shouted take to keep my ac unit running for more years Thank you LC!!!”
Google Review
JS
Justin Shapiro
West Hollywood, CA
“Great experience!!’ Leo came to my house in West Hollywood at 9pm !! I had an emergency, my ac stopped working out of no where i called LC heating and air from the phone call with the office to the time the tech came the service was just amazing. Leo came and had my ac running in no time. Thank you so much !! Highly recommended”
Google Review
GH
Greg Haroutunian
Los Angeles, CA
“Sunday morning discovered AC in the unit is not working, called everywhere, no one wanted to come the same day. LC Heating came the same day, fixed the problem which apparently wasn't easy to figure out. Very professional, calm and confident, pleasant to work with. Leo was the lead guy. Great experience, highly recommend it!”
Google Review
AV
Adam Valdies
Los Angeles, CA
“Leo and his team were amazing! I am so glad we called them to handle our AC/Heating issue. The problem was not clear at first and required substantial troubleshooting but Leo was extremely communicative and very professional throughout! He figured out the problem and we cannot thank him enough! Highly recommend!”
Google Review
LO
Leeyam Ohayon
Los Angeles, CA
“I called LC Heating & Air when my heating unit stopped working. He came quickly and fixed the problem fast. The technician was very kind and experienced. He explained the problem to me and gave me maintenance tips for the future. I definitely recommend LC Heating and Air if you're in need of these services.”
Google Review
AY
ariel. yona.
Los Angeles, CA
“Amazingly service me heater broke down and I was looking for a local company in my neighborhood. I found LC heating and air I can’t express in words how pleased I was with this company the owner Leo came out was very professional friendly and fixed my heater in no time !!! Highly recommended”
Google Review
KB
kevin benoit
Los Angeles, CA
“I cannot recommend this company more. They came, assess my issue and then ordered the right parts from the company and made an amazing install and transform my AC unit into a smart controlled AC unit which no Other HVAC company was able to do, or wanted to take the time that it took to do it”
Google Review
TY
Todd Yasuda
Los Angeles, CA
“Asher (LC Heating & Air) is the best, he kept me informed throughout the whole process. Everything he told me is exactly how things were done. I couldn’t have asked for a better person to work with. If you want to work with a reliable person and company, I would highly recommend him.”
Google Review
CK
claudia kleinschmidt
Los Angeles, CA
“Our AC was broken and had been dripping for a couple days. Once we called LC heating and air they sent out Asher to fix it immediately. He checked out the AC and fixed the problem on the spot. He was super professional and informative. Highly recommend Asher and the company!”
Google Review
DF
D Fan
Los Angeles, CA
“Leo is the absolute best! Had an emergency call and he came out right away in the early evening. Showed me how my units work and what the problem was. A few minutes later, it was fixed and working again! I cannot recommend this guy more highly. Call him and you'll be happy!”
Google Review
JM
Jamie Morgan
Los Angeles, CA
“LC Heating and AC is the best! I couldn’t recommend enough. It was a 100/10 experience. Helped me get to the bottom of repairing my AC that was very complicated and messed up by someone else. They are very professional and kind on top be being super knowledgeable.”
Google Review
DA
dan amiel
Los Angeles, CA
“Great service my heater stopped working out of the blue and we just had a new born I called lc heating and air they were the only ones that answered they came out and a hour my heater was up and running I couldn’t thank them enough . Highly recommended”
Google Review
YG
Yane G.
Los Angeles, CA
“Very helpful and very respectful. I called for a repair and was answered immediately, they were great in explaining what was going wrong and how they would fix it i was glad with there work and would definitely be calling them for any future repairs.”
Google Review
LA
Leetal Adelle Cohen
Los Angeles, CA
“We reached out to Leo and had a new HVAC system installed by him and his crew. Very happy with the results! Very professional, knowledgeable and patient. The whole process was very smooth, quick and clean. System works perfectly. Highly recommend”
Google Review
AM
Agam Mashiah
Los Angeles, CA
“I called lc heating to fix my heater in my house . We decided to replace the heater throughout the whole out process the customer service was great they were very communicative, professional and were very clean . Thank you again for the great job”
Google Review
CR
Charles Raffini
Los Angeles, CA
“HVAC system was leaking in the attic. Leo took my call late at night and came immediately. He stopped the leak and came back to make sure the system was working properly. Very responsive, good work and great value. Highly recommend them.”
Google Review
YY
yoav yerushalmi
Los Angeles, CA
“Scheduled an appointment very quickly for our HVAC unit that was having trouble cooling. Were very meticulous and clean. Helped idenitfy the issue and did a great job explaining what needs to be done and doing it. Highly recommended...”
Common questions about load calculation in Los Angeles
What is a Manual J calculation?
Manual J is the ACCA standard for calculating residential heating and cooling loads. It's a room-by-room analysis accounting for insulation levels, window area, orientation, local climate data, and building geometry to determine the exact capacity your home needs — not a rough estimate based on square footage.
Is a Manual J required in Los Angeles?
Yes. California's Title 24 energy code requires a Manual J (or equivalent) calculation for any HVAC installation or replacement requiring a permit. LADBS and most city building departments require Manual J documentation as part of the permit application package.
How often are LA homes oversized?
Very frequently. Studies of California residential HVAC installations find that 50–70% of systems are oversized, primarily because contractors use square footage rules of thumb rather than actual load calculations. In Los Angeles, the mild coastal climate and well-insulated newer construction means actual loads are often 20–30% lower than rules of thumb suggest.
Do you offer standalone load calculations?
Yes. If you're gathering bids and want an independent sizing recommendation, we perform standalone Manual J calculations for a flat fee. You receive a written report with calculated loads and sizing recommendations you can use to evaluate proposals from any contractor. Call (323) 970-3113 for current pricing.
My contractor said they don't need a load calculation. Is that normal?
Unfortunately common — many contractors size by square footage or match existing equipment size. This is a mistake and in California is a code violation for permitted work. A contractor who skips the load calculation is telling you something about how carefully they approach the work overall.
How does local climate affect the load calculation in LA?
Significantly. The design cooling temperature for Woodland Hills is around 107°F; for Beverly Hills it's around 96°F; for coastal areas like Culver City it's closer to 88°F. Using the wrong climate data can result in 15–25% sizing error. We use location-specific design data for every calculation.
Can a load calculation identify why my system isn't keeping up?
Yes. If we calculate the load for an existing home and compare it to the installed equipment's rated capacity, we can determine whether the system is undersized, whether the ductwork is the limiting factor, or whether there's a maintenance issue affecting performance. This is useful diagnostic information for comfort complaints.
How long does a Manual J calculation take?
Field measurement of a typical single-family home takes about 45–60 minutes. The calculation itself takes another 60–90 minutes. You receive the written report within 24 hours of the site visit.
Verified Reviews
What customers say about load calculation
Verified reviews from Los Angeles homeowners who used our load calculation service.
“Got quotes from four companies. LC was the only one that actually did a Manual J calculation and explained why our old system was oversized. The new properly-sized Trane system cools better, runs quieter, and costs less to operate.”
T
Tom W.
Woodland Hills, CA · Oct 2025
“LC recommended a smaller furnace than the other companies who quoted us. They explained that our old one was oversized and that a properly sized unit would heat more evenly and last longer. They were right.”
J
James R.
Glendale, CA · Oct 2025
“Had LC do a load calculation before choosing a new system. They recommended a smaller unit than the others — and they were right. Perfect comfort, lower bills, and the system doesn't short-cycle.”