Skip to main content

HVAC Sizes: How do I know what size HVAC I need?

June 11, 2019

When you are thinking about buying a new HVAC system, an important consideration is the sizes of available equipment. Just think: this new cooling and heating system will be serving your home for ten years or longer. It’s important to get this right!

For cooling and heating systems, it’s important to get the right size of equipment.

  • Bigger is not better – Rounding up might seem like a good idea, but over-sizing HVAC equipment can lead to lots of operational problems. An HVAC system that is sized too large will turn on and off regularly. That’s not only annoying for the people in the space, but the incessant startups will wreak havoc on your energy bills. And, it can lead to a shorter equipment lifespan.
  • Less is not more – It goes without saying that you don’t want to undersize your equipment. An under-sized HVAC will not be able to keep up with demand. Even if you think you’re not using very much of your HVAC system, consider the days where your home gets the heaviest use. For example, friendly gatherings or bake-offs in the kitchen. You want your system to be able to keep up in those scenarios!

Now you know the importance of investigating sizes of HVAC equipment. So how do you get to a number?

The Trouble with Using the Same HVAC Size

A lot of homeowners think that if they are replacing an HVAC system, they don’t need to worry about sizes. Just use the same size as the existing HVAC. Right?

The truth is that this approach can be problematic.

So before you get too far down the path in ordering a new heating and cooling system, consider if you’re experiencing any of these issues with your current setup:

  • Does your HVAC seem to be running constantly, or only turning off very briefly?
  • Conversely, does your HVAC system kick on and off, rarely staying on for more than a few minutes?
  • Are there areas of your home that aren’t being cooled or heated to your comfort levels?

If you are having any of these troubles with your cooling and heating system, you will be better off looking at different sizes of HVAC equipment. Our highly-trained technicians at Brody Pennell can help you choose the appropriate size system for your home.

Special Considerations for HVAC Sizes when Replacing

Homeowners that are replacing their HVAC should consider improvements that have been made to the home. Changing physical features of the home, adding energy-saving improvements, or remodeling spaces can impact the size of an HVAC system.

When you meet with a licensed contractor at your Los Angeles home, be sure to tell him or her about any changes you’ve made to the home since your current HVAC system was installed. Some of these items include:

  • New windows
  • Improved roof insulation
  • Additions of new spaces
  • Remodeled areas like kitchens, laundry rooms, bathrooms, or home gyms
  • Finished out spaces like attics, basements, or garages

Determining the Right Size of HVAC Equipment

So, what size does your air conditioner or furnace actually need to be?

If you’re building a brand new home, adding a new space, or you have done many renovations to your home, a load calculation needs to be performed.

load calculation takes into account a number of variables. For example, how many windows you have, the orientation of your home in comparison to the sun, and insulation in your walls and roof. A load calculation will also include the heat generated by the people, lights, and electronic devices in your home, just to name a few. An industry standard for load calculation is the Air Conditioning Contractors of America (ACCA) Manual J method.

When you have a final load value from the calculation, you’ll know what size your HVAC needs to be.

Isn’t there a simple rule of thumb?

If you’re doing research about HVAC sizes, you might find simplified methods for determining the load. For example, a certain number of tons per hundred square feet. Simple online tools will also spit out numbers for you. Homeowners should use caution when using these tools. These tools make sweeping generalizations about your home, and may not be able to produce accurate numbers.

Work with the best… and save money, too

The team at Brody Pennell has been in the heating and air conditioning business for more than 70 years. We understand how to size equipment correctly the first time by doing industry-standard heat load calculations.

Right now we are offering great specials on HVAC systems of all sizes. With the Carrier Cool Cash program, you can get up to $1,650 off a new HVAC system. You can combine this deal with other incentives, like utility rebates and financing. Now is a great time to buy if you are on budget – this is the best deal of the year.

Between our long history in LA, and our partnership with the best equipment manufacturers, our team can then provide a range of solutions that will best meet your needs. Give us a call to schedule an appointment today!


About The Author

Brody Pennell

Since 1945, Brody Pennell Heating & Air Conditioning is the committed to helping homeowners in the greater Los Angeles area experience total home comfort. In 2021, the readers of the Los Angeles Times voted Brody Pennell the Best HVAC Company in the area.

Request Service

Please fill out the form below to request an estimate or schedule service.

"*" indicates required fields

This field is for validation purposes and should be left unchanged.

Google logo with 4.9 star rating
Facebook logo with 4.9 star rating
Yelp Logo with 4.8 star rating
Louise G
1713312082
Superb service and very efficientAlex was an excellent technician…he was very knowledgeable and friendly and very helpfulUpdate 4/16: Kevin and Angel were wonderful, very helpful and knowledgeable. Will definitely ask for them again.
Estela N.
1713307133
Jose Rivera was helpful and fixed the issue with my new key pad and pump quickly and efficiently. He also made sure the remote access was working.
Maura L.
1713305706
Very knowledgeable and helpful!
Valencia M.
1713305546
Juan Molina was very thorough in his assessment of our heaters conditions. Was prompt and courteous.
Adam C.
1713305048
Great service from Michael I., Raul I., Jonathan A., Edwin C., Ramiro S. and Jesus F. -- excellent work done efficiently!
Israel
1713304719
RENÉ IS GREAT .
Cary T.
1713297820
Leo H and Tristen C were great!! Explained everything. Most important they did a terrific job!
Nancy H.
1713291151
Excellent work from both Stevens and David E. They did very thorough maintenance cleanup and before and after photos made it clear how necessary it is to do the twice yearly maintenance - will clearly keep system running at peak performance. Would recommend these two highly.
Bill B.
1713232027
Our technician Leonel was thorough in both accomplishing his goal of performing the seasonal tune-up on our system and updating my wife and me as to the overall health of our system. I found him to be competent, polite and trustworthy.
Egisia M El Basha H.
1713225482
Jose R.Pascul HGets on CRafa BPablo P. All excellent
Lauren K.
1713222854
Daniel B. went above and beyond fixing my air conditioning equipment today. He explained everything to me and made sure I knew exactly what he was doing throughout the process. My issue was tricky and he was able to figure it out and fix everything. Daniel is also incredibly kind and personable and made the process easy for me. I am completely satisfied with the service and will be contacting Daniel again for all my HVAC needs!
Mary H L.
1713221057
Ariel A. performed outstanding services! It was his first visit and he asked for an orientation which I thought was a very good approach. He wanted to make sure that he covered all the areas. We have been a customer of Brody Pennell for more than 30 years, and I can honestly say this young man is in the top 10% of the employees who have had the opportunity to service our home.
Margaret G.
1713219070
These guys are total pros. They know what they are doing and they explain everything clearly and the pricing is very transparent. Ivan and Jose C. are very friendly and efficient. I have just had a second very great experience with Armando. He came to maintain the heating system and was very thorough and efficient.4/15/2024: Ruben and Phil just came by to do maintenance on my ac system. They were so friendly and explained everything really well. They inspired total confidence. Another great Brody Pennell experience.
Rinzai-ji Zen C.
1713212152
We appreciate your recommendation of Ken. He demonstrated diligence and honesty throughout his time with us. I eagerly anticipate receiving the quote and reviewing its details. We look forward to the possibility of collaborating with Ken in the near future.
Andrea S.
1713210077
Jason, Hilton, And Leo were great. Polite and neat. All is well.
Michael C.
1713206188
Very professional and knowledgeable. We think the problem was solved due to high heat. Thank you
justin H.
1713205580
Armando and Benny were great. Highly recommend!
Mycroft
1713132842
Our old furnace was about at the end of its life. After discussion with our favorite technician Marco Ayala we decided to have a heat pump installed. A crew arrived this morning headed by Edwin Cabra. He was assisted by Diego B, S. Ramiro, Edgar H, Jonathan A. This team was well trained, worked well together and was finished this afternoon! Great job by all. That's why we have been customers for more than 15 years!!Update: there was a small issue with one of the wires. Ruben Medina found the issue and corrected it. Again Brody Pennell to the rescue! Thank you again!!Further update. Giovanny Quinterro found that the outlet being used had no power. He changed the outlet and we're back to having heat. Yay! Thank you once again!!
Daniel D.
1713054294
Diego B., Sergio S., Alberto H,. And Alex S. installed a brand new system in one of my units and replaced the piping. They took a job that's usually 2 days and did it in 6 hours. They were unobtrusive to the tenants, thorough, and genuinely nice guys. Works perfectly. Extra kudos to the guys for being cool with a couple of very friendly dogs that like to jump and lick. 10/10 would recommend.
Therese B.
1712963432
I just had David Mares here to service the A/C system that they installed 2 years ago. David was great at explaining all the pertinent information about the function and cleaning of my A/C / heating system. He took pictures to show me whatever potential issues there may be down the road. I would highly recommend Brody Pennell for the A/C / heating system and specifically David Mares as a technician.
Dominique Z.
1712961408
Juan Molina was wonderful and so helpful
Baden S.
1712961375
Ruben and Leo M were so great. So professional. So friendly. Great to work with
Jeff T.
1712961025
We just bought a complete HVAC system from Marcus at Brody Pennell and I've never felt better about a manager or a company, and I'm an exacting retired general contractor. Clear choices with zero pressure or upsellng, and character as solid as their well respected company, with the resources to back it up. Marcus was impressive with his expertise, and genuine honesty well beyond that of a company representative, as the kind of person you'd look for in a friend, who seems every bit as stable as this well established company. A real pleasure!
Nancy T.
1712960484
Kevin and David provided amazing customer service for our home in Beverly Hills. They were detailed, thorough, and did not try to rush through our appointment. I received text messages from David throughout their 3 hour visit with photos of the condition of our HVAC, areas of concern, and proof of filter changes! You really can't ask for more. These guys are the best and I would highly recommend them to anyone who needs HVAC maintenance/cleaning.
Nili H.
1712957739
Juan Romo was my technician. He was on time, thoughtful, clean and thorough. He was also very knowledgeable and answered my questions in detail. He took his time and didn’t rush. I’m always delighted with Brody Pennel’s service and recommend them highly. Today I had another service called by Ivan and Hilton And they were wonderful. Gave me a beautiful service and cleaned up as they went and tried to sell me a new filter which I’m for air purification
Joel S.
1712954903
Excellent service from Daniel and Maurice.
Kimberly A.
1712954768
Anthony Manzo was a very thorough and efficient technician. He was very helpful and I would highly recommend him .
Eric B.
1712952256
Once again, excellent service from Brody Pennell. David M. was great—helpful, friendly, and informative.
reyna C.
1712945385
Iván & Hilton were great !
Mike
1712944410
I signed up for a Brody Pennell service plan after they fixed my AC issue last year. I was very impressed with the easy scheduling and responsiveness from the team. Leo H. And Freddy came out today to do my annual AC maintenance, and they did another great job. I highly recommend working with this company!
Donna G.
1712884929
Very courteous, very professional and very thorough and clear in explaining all details.
william C.
1712878629
David Mares and Fabio Gomez were outstanding. Very detail oriented.
Angela B.
1712878029
Ariel A did my semiannual maintenance today. I was very pleased with how thorough he was throughout the process. He addressed Al, of my concerns.
samantha V.
1712873936
Last week we had Brody Pennell come and replace our heating system, I am glad that they sent an amazing crew. Rafael B, Rosendo V, Alessandro A, Nicolas and Jose Manuel. Very happy with the Company and their workers.
john D.
1712868398
My furnace would not start this am. I called for service at 9 am and Jose Rivera and Paul Pacheco arrived a few hours later. They diagnosed the problem as a flaky thermostat unit and replaced it. All if well now. Definitely 5 stars.
m T.
1712866112
Anthony Manzo any David Mares were great - a pleasure to work with. Knowledgeable professionals and nice guys. They did great work and we will request them for our next service.
chris O.
1712861955
Great people and service. Juan D was nice knowledgeable and got the job done. I’d recommend Brody to any and all family and friends.
Cameron P.
1712861849
Daniel B and David E came by to service my dual zone mini split. Simple job handled professionally and very courteously. Was glad to have their help and would hire them again.
Michael A.
1712861345
James H. and Pablo L. were professional, thorough and extremely nice. They represented your company very well.
Lloyd T.
1712860413
Fabio and David Mares rescued us when our furnace gave out. David gave us a clear, understandable explanation of the problems and how we could fix them. Mike, Raul, Pascual, and Frank installed our new energy efficient HVAC system. Paul and Jose added the finishing touches. We are grateful to the entire Brody Pennell team.
Richie B.
1712858599
Ruben and Leo M. were very professional, respectful and swift with their services as well as very detailed when summarizing the results of the job.
Zexuan Z.
1712858319
Daniel provided a good service of AC investigation. He's a friendly guy
Victoria O.
1712855311
Daniel B is excellent! Extremely helpful and solved all our problems!! Fabio Gonez and Juan Milina are terrific too!
brian H.
1712855276
Ivan and Ruben arrived promptly and were very thorough and professional.
Adriana S.
1712842013
David M was great!
Rocco F.
1712792797
Juan Molina was excellent! He explained everything in detail and made it easy for us to make a decision. Very trustworthy and knowledgeable, I would definitely recommend Juan to represent your company. The service technicians, Juan Munoz and Ramiros, were also top notch! They were on time, professional, and very friendly. They installed the heater and ducts in two days and everything was perfect. They even checked my plumbing while under the house and told me there no leaks. Great teamwork by your company, a well deserved five star review!Update: just had my six month service done by David E. and Kevin L., what a great team! Once again, everything was explained in detail with pictures and they serviced our AC and heater. Another five star review!
Jiravat “JW” W.
1712790853
Friendly and very considerate
×
js_loader

Service Request

"*" indicates required fields

This field is for validation purposes and should be left unchanged.
Louise G
1713312082
Superb service and very efficientAlex was an excellent technician…he was very knowledgeable and friendly and very helpfulUpdate 4/16: Kevin and Angel were wonderful, very helpful and knowledgeable. Will definitely ask for them again.
Estela N.
1713307133
Jose Rivera was helpful and fixed the issue with my new key pad and pump quickly and efficiently. He also made sure the remote access was working.
Maura L.
1713305706
Very knowledgeable and helpful!
Valencia M.
1713305546
Juan Molina was very thorough in his assessment of our heaters conditions. Was prompt and courteous.
Adam C.
1713305048
Great service from Michael I., Raul I., Jonathan A., Edwin C., Ramiro S. and Jesus F. -- excellent work done efficiently!
Israel
1713304719
RENÉ IS GREAT .
Cary T.
1713297820
Leo H and Tristen C were great!! Explained everything. Most important they did a terrific job!
Nancy H.
1713291151
Excellent work from both Stevens and David E. They did very thorough maintenance cleanup and before and after photos made it clear how necessary it is to do the twice yearly maintenance - will clearly keep system running at peak performance. Would recommend these two highly.
Bill B.
1713232027
Our technician Leonel was thorough in both accomplishing his goal of performing the seasonal tune-up on our system and updating my wife and me as to the overall health of our system. I found him to be competent, polite and trustworthy.
Egisia M El Basha H.
1713225482
Jose R.Pascul HGets on CRafa BPablo P. All excellent
Lauren K.
1713222854
Daniel B. went above and beyond fixing my air conditioning equipment today. He explained everything to me and made sure I knew exactly what he was doing throughout the process. My issue was tricky and he was able to figure it out and fix everything. Daniel is also incredibly kind and personable and made the process easy for me. I am completely satisfied with the service and will be contacting Daniel again for all my HVAC needs!
Mary H L.
1713221057
Ariel A. performed outstanding services! It was his first visit and he asked for an orientation which I thought was a very good approach. He wanted to make sure that he covered all the areas. We have been a customer of Brody Pennell for more than 30 years, and I can honestly say this young man is in the top 10% of the employees who have had the opportunity to service our home.
Margaret G.
1713219070
These guys are total pros. They know what they are doing and they explain everything clearly and the pricing is very transparent. Ivan and Jose C. are very friendly and efficient. I have just had a second very great experience with Armando. He came to maintain the heating system and was very thorough and efficient.4/15/2024: Ruben and Phil just came by to do maintenance on my ac system. They were so friendly and explained everything really well. They inspired total confidence. Another great Brody Pennell experience.
Rinzai-ji Zen C.
1713212152
We appreciate your recommendation of Ken. He demonstrated diligence and honesty throughout his time with us. I eagerly anticipate receiving the quote and reviewing its details. We look forward to the possibility of collaborating with Ken in the near future.
Andrea S.
1713210077
Jason, Hilton, And Leo were great. Polite and neat. All is well.
Michael C.
1713206188
Very professional and knowledgeable. We think the problem was solved due to high heat. Thank you
justin H.
1713205580
Armando and Benny were great. Highly recommend!
Mycroft
1713132842
Our old furnace was about at the end of its life. After discussion with our favorite technician Marco Ayala we decided to have a heat pump installed. A crew arrived this morning headed by Edwin Cabra. He was assisted by Diego B, S. Ramiro, Edgar H, Jonathan A. This team was well trained, worked well together and was finished this afternoon! Great job by all. That's why we have been customers for more than 15 years!!Update: there was a small issue with one of the wires. Ruben Medina found the issue and corrected it. Again Brody Pennell to the rescue! Thank you again!!Further update. Giovanny Quinterro found that the outlet being used had no power. He changed the outlet and we're back to having heat. Yay! Thank you once again!!
Daniel D.
1713054294
Diego B., Sergio S., Alberto H,. And Alex S. installed a brand new system in one of my units and replaced the piping. They took a job that's usually 2 days and did it in 6 hours. They were unobtrusive to the tenants, thorough, and genuinely nice guys. Works perfectly. Extra kudos to the guys for being cool with a couple of very friendly dogs that like to jump and lick. 10/10 would recommend.
Therese B.
1712963432
I just had David Mares here to service the A/C system that they installed 2 years ago. David was great at explaining all the pertinent information about the function and cleaning of my A/C / heating system. He took pictures to show me whatever potential issues there may be down the road. I would highly recommend Brody Pennell for the A/C / heating system and specifically David Mares as a technician.
Dominique Z.
1712961408
Juan Molina was wonderful and so helpful
Baden S.
1712961375
Ruben and Leo M were so great. So professional. So friendly. Great to work with
Jeff T.
1712961025
We just bought a complete HVAC system from Marcus at Brody Pennell and I've never felt better about a manager or a company, and I'm an exacting retired general contractor. Clear choices with zero pressure or upsellng, and character as solid as their well respected company, with the resources to back it up. Marcus was impressive with his expertise, and genuine honesty well beyond that of a company representative, as the kind of person you'd look for in a friend, who seems every bit as stable as this well established company. A real pleasure!
Nancy T.
1712960484
Kevin and David provided amazing customer service for our home in Beverly Hills. They were detailed, thorough, and did not try to rush through our appointment. I received text messages from David throughout their 3 hour visit with photos of the condition of our HVAC, areas of concern, and proof of filter changes! You really can't ask for more. These guys are the best and I would highly recommend them to anyone who needs HVAC maintenance/cleaning.
Nili H.
1712957739
Juan Romo was my technician. He was on time, thoughtful, clean and thorough. He was also very knowledgeable and answered my questions in detail. He took his time and didn’t rush. I’m always delighted with Brody Pennel’s service and recommend them highly. Today I had another service called by Ivan and Hilton And they were wonderful. Gave me a beautiful service and cleaned up as they went and tried to sell me a new filter which I’m for air purification
Joel S.
1712954903
Excellent service from Daniel and Maurice.
Kimberly A.
1712954768
Anthony Manzo was a very thorough and efficient technician. He was very helpful and I would highly recommend him .
Eric B.
1712952256
Once again, excellent service from Brody Pennell. David M. was great—helpful, friendly, and informative.
reyna C.
1712945385
Iván & Hilton were great !
Mike
1712944410
I signed up for a Brody Pennell service plan after they fixed my AC issue last year. I was very impressed with the easy scheduling and responsiveness from the team. Leo H. And Freddy came out today to do my annual AC maintenance, and they did another great job. I highly recommend working with this company!
Donna G.
1712884929
Very courteous, very professional and very thorough and clear in explaining all details.
william C.
1712878629
David Mares and Fabio Gomez were outstanding. Very detail oriented.
Angela B.
1712878029
Ariel A did my semiannual maintenance today. I was very pleased with how thorough he was throughout the process. He addressed Al, of my concerns.
samantha V.
1712873936
Last week we had Brody Pennell come and replace our heating system, I am glad that they sent an amazing crew. Rafael B, Rosendo V, Alessandro A, Nicolas and Jose Manuel. Very happy with the Company and their workers.
john D.
1712868398
My furnace would not start this am. I called for service at 9 am and Jose Rivera and Paul Pacheco arrived a few hours later. They diagnosed the problem as a flaky thermostat unit and replaced it. All if well now. Definitely 5 stars.
m T.
1712866112
Anthony Manzo any David Mares were great - a pleasure to work with. Knowledgeable professionals and nice guys. They did great work and we will request them for our next service.
chris O.
1712861955
Great people and service. Juan D was nice knowledgeable and got the job done. I’d recommend Brody to any and all family and friends.
Cameron P.
1712861849
Daniel B and David E came by to service my dual zone mini split. Simple job handled professionally and very courteously. Was glad to have their help and would hire them again.
Michael A.
1712861345
James H. and Pablo L. were professional, thorough and extremely nice. They represented your company very well.
Lloyd T.
1712860413
Fabio and David Mares rescued us when our furnace gave out. David gave us a clear, understandable explanation of the problems and how we could fix them. Mike, Raul, Pascual, and Frank installed our new energy efficient HVAC system. Paul and Jose added the finishing touches. We are grateful to the entire Brody Pennell team.
Richie B.
1712858599
Ruben and Leo M. were very professional, respectful and swift with their services as well as very detailed when summarizing the results of the job.
Zexuan Z.
1712858319
Daniel provided a good service of AC investigation. He's a friendly guy
Victoria O.
1712855311
Daniel B is excellent! Extremely helpful and solved all our problems!! Fabio Gonez and Juan Milina are terrific too!
brian H.
1712855276
Ivan and Ruben arrived promptly and were very thorough and professional.
Adriana S.
1712842013
David M was great!
Rocco F.
1712792797
Juan Molina was excellent! He explained everything in detail and made it easy for us to make a decision. Very trustworthy and knowledgeable, I would definitely recommend Juan to represent your company. The service technicians, Juan Munoz and Ramiros, were also top notch! They were on time, professional, and very friendly. They installed the heater and ducts in two days and everything was perfect. They even checked my plumbing while under the house and told me there no leaks. Great teamwork by your company, a well deserved five star review!Update: just had my six month service done by David E. and Kevin L., what a great team! Once again, everything was explained in detail with pictures and they serviced our AC and heater. Another five star review!
Jiravat “JW” W.
1712790853
Friendly and very considerate
×
js_loader