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The 7 Biggest Mistakes That HVAC Contractors Make

A Bad Duct Retrofit

A bad duct retrofitHeating and air conditioning contractors, like the rest of us, make mistakes. They make mistakes that hurt performance and efficiency of the HVAC systems they install and maintain. They make mistakes that hurt their customers sometimes. And they make mistakes that hurt their businesses. Let’s look at 7 of the biggest mistakes today.

Heating and air conditioning contractors, like the rest of us, make mistakes. They make mistakes that hurt performance and efficiency of the HVAC systems they install and maintain. They make mistakes that hurt their customers sometimes. And they make mistakes that hurt their businesses. Let’s look at 7 of the biggest mistakes today.

Although Energy Vanguard is not an HVAC contractor, we have a lot to do with heating and air conditioning systems. We train home energy raters (a.k.a. HERS raters) in the RESNET protocols and building analysts in the BPI protocols. We also do quality assurance for HERS raters, which requires us to enforce guidelines for programs like ENERGY STAR New Homes. We may not be licensed to install and maintain equipment, but we know a thing or two about it.

If you’ve been a reader of this blog for a while, you know that I write about HVAC a lot, and many of those articles are pointing out problems. Turns out, they’re very easy to find because so many HVAC contractors leave big messes in their customers’ homes. Not all HVAC contractors work this way, of course, but the majority do. The good ones have successful businesses not only because they do good work for their customers, but they make more money by coming in and cleaning up the messes left by the sloppy contractors.

Here then, are what I see as the top 7 mistakes that HVAC contractors make:

1. Not understanding combustion safety

If an HVAC contractor responds to a call about carbon monoxide, they’ll usually go straight to the furnace and look for cracks in the heat exchanger. When they find that it’s OK, they often assume it must have just been a false alarm, so they change the batteries in the CO alarm. David Richardson, a former HVAC contractor who now works fulltime for the National Comfort Institute training people in combustion safety and air flow, wrote a guest post for us here a couple of years ago about this very issue.

The problem is that most HVAC contractors don’t know much about backdrafting of combustion appliances. Nor do they test for it. If you’re an HVAC contractor and not testing for flue gases and worst-case depressurization on these calls, you’re leaving a potentially dangerous situation. You never want to find out the next day that the people in the house you just visited are in the hospital with CO poisoning.

2. Focusing on ‘the box’ and ignoring air flow

This is the problem that I’ve probably written more articles about than any other. If the vast majority of HVAC contractors did professional quality work, I wouldn’t be able to go into house after house after house and find the kind of duct problem you see at the top of this page. If all HVAC contractors were pros, no one would know what a ductopus (below) is. If HVAC contractors understood air flow, most duct systems would be larger than they are.

Release the Kraken! The Ductopus Kraken!

Mike MacFarland of Energy Docs, an HVAC contractor in California, told me last year at Building Science Summer Camp that he pretty much never does a system changeout without also doing a duct changeout. Why? Because he knows that the existing ductwork, even if it’s relatively new, probably wasn’t sized right, is too leaky, and would lead to more trouble and expense than just starting over.

3. Ignoring the opportunities in home performance

In the residential market, HVAC contractors go into people’s homes every single day. They go into attics, crawl spaces, and basements, where they can see Building enclosure problems are rampant.the quality of the insulation and air sealing in the home’s building enclosure. Even if the HVAC contractor doesn’t do the insulation and air-sealing work, it’s a great complementary service to advise the homeowners on the other work their home could use to improve its overall performance.

It seems a bit paradoxical that so many HVAC company names include the word ‘comfort’ yet they don’t really address all the issues that affect comfort. Once you truly understand that naked people need building science, you know that mechanical systems aren’t the answer to all comfort problems.

And if you walk out of a house without looking at all of the home performance issues, you’re leaving money on the table, as the saying goes. Would you rather walk out with a $7000 contract or a $20,000 contract?

4. Forgetting the V in HVAC

Ah, yes, ventilation. The insulting way to state this is that any HVAC contractor who doesn’t address the V in HVAC is just a HAC (read: hack). New homes are tighter than ever because of energy codes that require higher levels of air-sealing and in some cases, blower door tests to verify the airtightness. Tight homes need mechanical ventilation. All homes need spot ventilation in kitchens and bathrooms.

Are you really including the V in HVAC? Do you know what ASHRAE 62.2 is? Do you understand the 3 strategies for providing mechanical ventilation (positive pressure, negative pressure, and balanced)? Have you measured the air flow in your ventilation systems?

5. Skipping the math

My friend John Barba, a trainer for hydronics manufacturer Taco, suggested this title, and I love it. HVAC contractors like rules of thumb. They also rely on what they think worked in the past. “Son, this is the way we’ve always done it around here, and we’ve been in business longer than you’ve been alive.”

Well, guess what. Heating and cooling systems aren’t the same as they were 50 years ago. Nor are homes. Rules of thumb don’t work because every house is different. If you want to size a system properly, you’ve got to come up with some way of getting at the rate of heat loss and heat gain in the home you’re working on. Manual J is probably the best way for new homes, and timing the existing system’s runtime during design conditions is the best for existing homes (if you have that option).

hvac load calculation equipment sizing manual e contractor mistakes

HVAC systems are complex technology. If you’re relying on rules of thumb or doing things the way you’ve always done them, then you’re not serving your customers well.

6. Trying to be the low bidder

The race to the bottom results in everyone being a loser. The ones who don’t get the contract lose. The one who gets the contract can’t do the work properly because they have to scrimp on labor and materials. And the homeowner loses because, as the saying goes, you get what you pay for.

When contractors try to get low-bid work, they have to keep all their costs as low as possible. They hire poorly trained techs and then don’t do enough—or anything—to get them trained properly and keep them updated. They use equipment that won’t last. They do the least work they possibly can on the distribution system. (See #2 above.)

This is no way to run a business. Because there are so many companies willing to do this, though, there will always be room for smart contractors to come in and do things right.

7. Failure to use house-as-a-system thinking

First, you’ve got to get to HVAC-as-a-system thinking by getting past the sins described in numbers 1, 2, and 4 above. Once you include combustion safety and distribution and ventilation in your scope, you’re ready to go beyond and look at the whole house. This leads to the opportunities in mistake number 3 above, of course, but it’s bigger than that. When you understand the house-as-a-system concept, you become a problem solver. You know how to listen to homeowners and help fix things so their daughter’s cough goes away or the mildew in the bathroom stops growing or that one room they can’t stand to be in becomes part of their living space again. This is Building Science 101, and smart HVAC contractors know this stuff.

The bottom line

If you’re an HVAC contractor, which path will you choose? One path leads to problems. You constantly have to find new customers because it’s hard for the ones you have to feel any loyalty to you if your work isn’t remarkable. And if your customers are always looking for the low bid, you may get them one time, but the next time you follow up with them, you find that someone underbid you. Also, if you’re making the 7 mistakes above, you may find your work featured in the Energy Vanguard Blog…as an example of what NOT to do.

The other path leads to greater profitability, happier and more loyal customers, more referrals, and peace of mind. The choice is yours, HVAC contractors.


Related Articles

Building Science 101

Why Won’t the HVAC Industry Do Things Right?

The Education of a Combustion Safety Instructor

Naked People Need Building Science

This Post Has 25 Comments

  1. The most important factor in
    The most important factor in economy and comfort is the surface temperature of walls, ceilings, and floors. If the ceiling is boiling in summer at 120 + degrees or in the winter in 40’s or 50’s, one will NEVER feel comfortable in the space, even with tons of cooling or heating. Good example is walking by cooler section in a store in the summer. One freezes even though air temp in mid 70’s. So make house right, and install equipment to handle 90% less load. But unfortunately that is not good business for HVAC people…and thus not done

  2. Great topic, right on. I
    Great topic, right on. I completely agree with everything you said.  
    In Chicago the problem is that you still have to compete with the cheap guys and there the ones who get the jobs because its mostly about money. Sadly I think Americans in general just dont care about energy efficiency, climate change etc. They will spend money on a flashy kitchen but theres just no flash in insulated ducts and condensing furnaces. At least that is what i see in Chicago. Would be interested in attitudes elsewere.

  3. My top mistakes and top
    My top mistakes and top positives 
    Mistake 1 Under charging for a proper job 
    Postive 1 Taking the time to learn what we don’t know and spending the time doing it 
    Mistake 2 Assuming that we know almost everything and what we don’t know won’t matter 
    Positive 2 Taking the time to explain to the customer what is going on. 
    Mistake 3 Concentrating only on the immediate symptom 
    Positive 3 Listening to the customer — they live with the HVAC system the whole time. 
    Mistake 4 Repeating mistakes 1 through 3 
    Positive 4 Learning from every mistake we make.

  4. On the whole, the industry
    On the whole, the industry averages less than 2.6% profit and owners typically make around $35k a year, or about $13.50 an hour, on average. The low bid almost always gets the job and there are too many people willing to work for no return. Much of this is the result of “technicians” venturing out to be business owners w/out understanding the basic fundamentals of what it takes to run a business.  
    The prices are often based on a “price per ton” mentality so the incentives to size right and design right are also out of whack.  
    The industry needs a makeover.

  5. Allison, 

    This is a good summary of the state of the industry at its worst. And there are many equally good HVAC contractors out there who never make these mistakes. You arer too generous to characterize some of these as mere mistakes. 
    How do we who are on the buying end of the equation move from the status quo to a balanced state where most contractors are beyond the point of “making mistakes” to a higher level of engineering and professionalism. 
    As a home builder for years, I wrote specifications that addressed some of these mistakes. Every contractor bid against the same specs. At the time that I would inspect their work, and I pointed to issues that did not meet the specifications, or I asked for a copy of the Manual J calculations, I hear more excuses than I have time to repeat. I have even helped contractors do the manual J calculations and then discovered this was obviously the first one they had every done. 
    Where is SMACNA in all of this with some strong efforts to upgrade the professionalism of the residentials side of the HVAC industry?

  6. Allison, 

    First, I think you should take it as a sign of success that trolls lie in wait for your posts;-) 
    Point #6 seems, to me, to be at or near the root of the problem. This attitude is rife in many contracting fields. The fear of losing work drives prices down, lack of profit makes the fear of losing work worse. 
    When I’m trying to get past this mindset I always ask contractors if they can compete with Walmart. No matter the business there is always a Walmart out there. Unfortunately there are many people who can’t get past the “cheaper than thou” concept and who can’t see the hole they’re digging for themselves.

  7. Having run a HVAC contracting
    Having run a HVAC contracting company for 30 years you’re spot on about the mistakes. Even more than professional mistakes, they are all business mistakes as you point out. 
    Not every $700.00 job turns into a $7000.00 job, but a lot of “customers” do turn in to “clients”. The really tragic part is that all this stuff is so simple if you just do it right.  
    Not only do HVAC often contractors fail to use “house-as-a-system” thinking, we often fail to use HVAC-system-as-a-system thinking. Mistake #2 is a real problem when it comes to measuring system performance in real time and looking at equipment performance as a whole. We finally got the system-as-a-system performance thing down to under five minutes …air flow and all. 
    Oddly enough the ductopus in the picture may have enough arms to move enough CFM. Even more weird is that there is a real outside possibility (one in a thousand) that air flow is balanced. Once the ductopus is installed, the only people that can make it right are the homeowners. I am curious; did the homeowners take your advice and change the ducting on this job? Do homeowners always take your advice?  
    Giving advice to a homeowner is no different than you giving advice to HVAC contractors. You can lead them to water, but you can’t MAKE them drink. The responsibility of any professional ends with the recommendation. But failure to diagnose and recommend is simple malpractice. 

  8. Nice post Allison! I
    Nice post Allison! I particularly like the free manual E training.  
    “timing the existing system’s runtime during design conditions is the best for existing homes (if you have that option)”  
    I really like this! While I like to use this to inform modelling, rather than replacing it I find it very exciting to see others feel this is a strong approach. 
    Wanna see some grossly oversized furnaces based upon timing? Check out the Ecobee charts for my rental property. (Thinking I’ll take one furnace out and it might fix things)  

  9. Being the hopeful, optimistic
    Being the hopeful, optimistic guy that I am, I prefer the “opportunities” angle. HVAC is a very difficult business these days. Race to the bottom pricing, commoditization, no meaningful tax credit, the new housing slump–all make for challenging times. Your “mistakes,” in my view, are the perfect roadmap for how smart companies will differentiate themselves. (And many already are.) I know here in Maine that the architect/builder community is starved for mechanical professionals that “get it.” And, by the way, integrated home performance hvac companies drive higher ticket jobs and better margins. AKA MAKING MORE MONEY.

  10. Great post Allison! &nbsp
    Great post Allison!  
    It has offended some of the people that commented on your post, but I encourage them to take each listed “mistake” and reflect on their business. “IF” the are not doing these things after an “Honest” assessment, then they should be selling these mistakes as things they don’t do and how they add lots of VALUE to their jobs.  
    Your list of mistakes is similar to what we find in our area too. It is not COMMON AT ALL to look at the picture totally, but times are changing. It is wasted opportunity and wasted efforts if the “whole house” is not taking into account. HVAC is vital to homes and those contractors commenting on here should not feel attacked unless they are the ones making these mistakes. HERS Raters, BPI Pros, NCI, NATE, ACCA, ETC….does not give you the experience that the field gives and should not be a magnanimous title. We ALL need to work together to get better. We all need to be honest and use our collective wisdom to do things better. We should not duplicate Congress in our quest to make homes better. We need to work “across the aisle” since we need each other!  
    The people you have commenting on this post have a lot of experience and should be recognized.  
    Thank you for this timely and time’less’ post. The industry is changing and those that spread dislike against the HP industry are the very ones missing the opportunities you are listing to be different, excel, improve and at the end of the day…make more money. It cost too much money to get that phone call and opportunity to build a client for life. Messing that up creates a battle for growth and prosperity of a business. You are spot on with this post!

  11. This is a great article.
    This is a great article. Thanks for posting it.

  12. Hello Allison,  &lt
    Hello Allison, 
    We are in Dallas, TX and have a 4 year old Hydronic system using a Rinnai tankless water heater and an air exchanger that has an evaporator coil that has a lot of rust around the U shaped copper tubes that loop around the ends of the evaporator coil. What causes this and what is the proper way of treating the issue before it fails? 
    Todd H. Dallas, TX

  13. Allison, 

    You know you’re preaching to the choir with me on the immediate topic. But most HVAC guys are honest, hardworking gents trying their best to feed their families in a tough business with a history of really bad habits. Perhaps we should consider a little less piling on and a little more constructive support. After all, the guys are essential partners to what we are trying to accomplish.  
    I want to throw out a challenge. Why not write an article on The Seven Effective Habits of Highly Competent HVAC contractors, explaining how they can break free from the low bidder competitive nature of the business without starving to death. It sure would be nice to have a yellow page full of quality contractors to call on.

  14. Great article. As someone
    Great article. As someone who is not an HVAC contractor, but who (out of necessity) has learned the importance of all these issues, how does one go about finding an HVAC contractor who thinks at this level? I just bought a house in Nebraska and want to put in a new system, including new ductwork. I have interviewed probably 15 contractors already, and literally, I know more than most of them.  
    The item about “doing the math” is the big one. It doesn’t take long to figure out when someone is “winging” it and using rules of thumb, versus doing the math. Most of the people I have talked to have never even heard of manual J. 
    I understand the big picture issues, but obviously still can’t do this all by myself. As I am reading some of the posts here, from people who clearly think these tings through, I am thinking “do you live near me?” and if not, how do I find someone like this who lives near me? People say “ask around” but that isn’t anything tangible. Any advice would be appreciated.

  15. David D.:
    David D.: Your question is an important one, and I wish I had an answer for you that was as good as the question. I did write an article about the topic a while back that gives you some guidance, so check it out first: 
    5 Questions to Ask When Replacing Your Air Conditioner  
    It’s a good start anyway. Good luck!

  16. Hello. I’d like to post on
    Hello. I’d like to post on behalf of the last comment re: “ask around”. 
    You should “look around” on the web; reviews tell you a lot about a business — esp.over time.  
    We ask our customers to review us. We want them to, and we are confident of the things they’ll say. A good company will stand up for what they are doing and selling. 
    So always read reviews and look for reviewed companies, and review them as well.  
    I would also always get bids or work orders listed in writing, always have a receipt, and always have the warranty known up front and in writing.  
    I feel strongly too that you should be able to ask questions and that things should be explained to you by the person doing them. Know too who is in your home/bsns.. as in are they qualified/certified/ 
    permits pulled..?? 
    Good luck

  17. I’m fairly young to the hvac
    I’m fairly young to the hvac field I guess? I’m 30 Years old. My business is in Florida. I like the points you have made in your blog and most of your points are spot on!. I take the same approach in the way I have developed my business plan. Many HVAC guys know what is the right way to do things but, it is hard to compete with these HACKS… So many of them just do what they have to to get the contract. We all have families and responsibilities. I think the education of the consumer is the key to correcting many problems we face today. Not only human comfort but the limited resources this planet has for us to consume. Yes the way you wrote this will offend some HVAC guys but well it is what it is? lol! But keep in mind HVAC is a trade that is all trades combined carpentry,electrical,fluid dynamics, mechanics, design and last but not least we are also psychiatrists LOL Cause People are crazy Sometimes and we can lead a horse to water but we can not make them think. Education of the public is the key LOL. Also did an HVAC guy really design that Kraken? Or was it a crazy homeowner? your blog really attacked our trade but hey we are big boys we can take it lol!!! thanks for trying to educate the people! I will be looking forward to reading more of your stuff and the older stuff too!

  18. All the points you hit in
    All the points you hit in your original post are valid, and there are a lot of contractors out there that simply do not know how to do things right. But conversely, there are a lot of contractors that do, and decide not to spend the time and resources doing them. Me for example, I’m no stranger to a manual J, but what I will not do is spend an extra hour to hour and a half doing a manual J on every customers home when all they are looking for is the cheapest price possible. With proper questions and observation, an educated person can deduce what can of customer they’re dealing with in 5 minutes or less. Typically, if my customer wants a new system due to efficiency or the old one has started failing a lot but doesn’t tell me they have had any comfort issues or air flow problems, I’m simply going to replace there system with the same tonnage and save them the extra cost of doing a manual J that’s written into the cost of an estimate. And if there are contractors out there that don’t increase there cost to cover the time to do a proper manual J, then there’s one part of the problem right there. Also, these profit margins I read about in other parts of the country, like 3-5 percent profit margins, what is that all about? How much work has to be performed to make any money at those margins? Someone please post what some typical repairs or replacements cost that make those profit margins. I sell condenser fan motors at $450 to $550 plus tax and am one of the cheapest companies in my area, last I checked that isn’t even close to a 3% profit margin.

  19. Amen to nick s. the reason
    Amen to nick s. the reason manual j’s are not provided? People won’t pay for them. Nor will they pay for hrv’s in most cases. They will however, award the job to the lowest bidder no matter what the end product looks like or how it works. Then they will go to the Internet to complain about how the hvac industry is a bunch of thieves and crooks.

  20. Great article. I have been in
    Great article. I have been in this industry for 22 years. In my opinion, those causes are from lack of inspection forces, certification requirements, builder, vendor’s greeds, poor development designs and qualifications. I strongly oppose “cost affordable” for the consumers reason, because over 50% of this consumers (this is not documented, it’s my opion) don’t understand the work quality . They just want to avoid the riff offs if the those costs are greatly different. Their final decisions are usually favor in less cost for the installations than quality. For this reason, poor quality installers are the winners. To improve this for the consumer benefits, we should start from the equipment vendors. First, the equipment orders to be release with inspection applications. The manufacturer’s warranty are only qualified by the installation approvals from high skill, educated inspectors. These inspectors should be paid fairly base on their skills and responsibilities.  
    Eat me…..

  21. Definitely, I agree with Mark
    Definitely, I agree with Mark! Sometimes, customers don’t understand that if you spend less, you get less and if you spend more, you get quality work done.

  22. The problem I’m having in va
    The problem I’m having in the supply houses sell equipment to anyone with a freon card . Everyone should be Licensed and insured. I lose a lot of business because these guys just want to make enough money for rent . Supply houses should require you to be a master at your trade but instead it’s all about money for them . If Licensed contractors made a big deal about this we would probably be able to make a good living and be proud to have passed the masters and received a valid contractors license . But instead any Joe blow can walk in and buy the equipment. Where I had to work my ass off to pass the test . Just sucks

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