The Case for Home Ventilation Specialists
You’d think that HVAC companies would have this locked down. The V in HVAC, after all, stands for ventilation. But ventilation falls below duct systems for many contractors. And duct systems are below what’s in the box that makes the heating or cooling (e.g., heat pump, furnace, or boiler). With many states now mandating whole-house ventilation systems, though, we need a class of worker in the HVAC industry — home ventilation specialists.
The term “ventilation” can mean a variety of things. Here, I’m talking primarily about mechanical ventilation in a home, excluding radon mitigation, which does have its own specialists. That includes exhaust fans in bathrooms, kitchens, and garages as well as whole-house ventilation systems.
The problem: Ventilation is nobody’s job
Let’s start with bath fans. In many new homes, the electrician installs the housing. Since they don’t install the duct, they have a 50/50 chance of pointing it in the right direction. The photo below shows one of the many wrong choices I’ve seen.
Last year, Martin Holladay, the now-retired editor of Green Building Advisor, asked a bunch of us in the industry about why we thought the HVAC industry was such a mess. (You have to be a GBA Prime member to read the full article, but it and the followup about solutions are great. GBA is a great resource, though, and worth the membership.) Here was part of my response:
An HVAC tech has to have a huge amount of knowledge to do their job. Here’s a list of a few things they need to know: basic skills like tool use, soldering, brazing, etc.; framing basics, like when you can and cannot cut a framing member or how big a hole you can cut; plumbing basics for condensate lines or hydronic distribution; electrical wiring, measurements, setting DIP switches, etc.; measuring and adjusting refrigerant levels in ACs and heat pumps; venting combustion appliances safely; dealing with gas, oil, and propane safely; troubleshooting malfunctioning equipment; air flow, pressure measurement, ductwork, etc.
Notice that I didn’t mention anything about ventilation. That’s because most companies don’t make it a priority. There are too many other things they see as more important. When they have to do ventilation, they do what they can with the skills they have.
The result is ventilation systems that don’t work well. Bath fans often move about half the air they should. In the case of more complicated systems like energy recovery ventilators (ERVs), the mistakes are numerous. Robert Jordan of Achieve Home Energy Advisor in Massachusetts told me recently that every ERV installation he sees has problems, some of them serious. (See this article I wrote about some photos he sent me.)
Why we need home ventilation specialists
Ventilation is part of building science, indoor air quality, and HVAC. The standards and codes that govern it can be complex. They’re also frequently misapplied. People and companies who specialize in ventilation will have a comprehensive understanding of all these issues and know how to apply them.
In addition, a home ventilation specialist needs to know the local climate, the homeowners’ needs, different ventilation strategies, the range and types of equipment available, the various ways to move the air, and more. Should you go with an ERV or a ventilating dehumidifier? Or would a central fan-integrated supply system be better because of its lower upfront cost? Should you go with independent ventilation ducts or tie them in with the heating and cooling ducts?
When ventilation systems don’t get designed, installed, commissioned, or maintained properly, serious problems can follow. Moisture problems that lead to rot and mold. Indoor air pollutants that linger in the home. Wasted energy from ventilation systems that run but don’t actually do anything because no one knows there’s a problem. And on and on.
The truth is that ventilation is too important and too complex to leave to workers who don’t understand the intricacies and for whom it’s a low priority.
The market failure
Architects, builders, and HVAC contractors sometimes see ventilation as an add-on service. Often, however, it’s just one of those things they have to do to check a box on their list and get paid. Kinda like having to watch an ad so you can see the full video you want to see on YouTube.
Another problem with the market is there’s no trade identity for home ventilation specialists. There’s also no clear credential that tells customers, “This is the person you need.” And there’s certainly no licensing of ventilation pros.
Because of those deficiencies, homeowners don’t even know to ask for it. Worse, they often don’t know they need it. A home with a malfunctioning ERV might be running and using energy, as I mentioned above, without coming close to doing what it should.
What home ventilation specialists would do
Below is a list of the things ventilation specialists would do. Some of these tasks could and probably should be split among different people and perhaps different companies. Similar to my longstanding plea to separate design from installation in heating and cooling, design might be best separated from installation in ventilation, too. Here’s the list.
Design – The ventilation designer should have the most comprehensive knowledge of anyone in the ventilation industry. They’re the ones who use their overall understanding of ventilation, code requirements, homeowner needs, and equipment capabilities to come up with a design and specifications that will work. And they’ve got to be masters of the ASHRAE 62.2 residential ventilation standard and how it’s implemented in the International Residential Code.
Installation – The installer should first RTFM – Read The Friendly Manual. Relying only on the design documents might get them in trouble, especially if they’re installing equipment they’re not familiar with.
Commissioning – The one commissioning could be the same person who installed the system, but they’ll need some additional tools and skills.
Maintenance – Some homeowners are capable of and interested in maintaining their own stuff. Many aren’t. Without someone to come and change filters, check for proper operation, and look at basic indoor air quality metrics, ventilation systems can go south in a hurry.
Assessment of existing systems – I called out assessment separately, but it could be done by the same person or company that does maintenance.
The path forward
Residential ventilation is an unclaimed niche in the HVAC market. I’d love to see a lot of HVAC companies with home ventilation specialists on their staffs. Building codes have done wonders for improving airtightness, but they aren’t going to make HVAC companies better at ventilation. Duct systems might meet the duct leakage requirement, for example, but still move the wrong amount of air and be too noisy.
That leaves a huge opportunity for companies willing to invest in the skills and tools to take command of this niche. You don’t need to be a licensed mechanical contractor to install ventilation systems, at least not in most places. What could be useful, though, is to have a nationwide credential that lets everyone know you’ve got the training and the skills to be a home ventilation specialist.
This may be difficult to pull off in rural areas or states with building codes that don’t require much for ventilation. Even in some larger areas, the local code requirements will make a difference. But there are complementary services a ventilation contractor could offer to support their growth. High-efficiency filtration installation and retrofits would be a great add-on. So would IAQ assessments.
And speaking of IAQ, even though I’m focusing on ventilation here, you need to remember that it’s only one part of achieving good indoor air quality. The others are all fair game, too.
I’ve been talking about this for years and hoped I would see companies specializing in ventilation popping up all over the country. I’m still waiting. The unclaimed market is still waiting. Are you ready to claim it?
Allison A. Bailes III, PhD is a speaker, writer, building science consultant, and the founder of Energy Vanguard in Decatur, Georgia. He has a doctorate in physics and is the author of a bestselling book on building science. He also writes the Energy Vanguard Blog. For more updates, you can follow Allison on LinkedIn and subscribe to Energy Vanguard’s weekly newsletter and YouTube channel.
Related Articles
7 Steps to Good Indoor Air Quality
11 Ways to Screw Up an ERV Installation
6 Options for Ventilating Homes in Humid Climates
Comments are welcome and moderated. Your comment will appear below after approval. To control spam, we close comments after one year.
I’ll give an anecdote to second your point, Allison. When I worked for an ERV manufacturer, I did what all good industrialists do… I joined committees to help write the regulations for our industry. I found myself often advocating for more rigorous standards than many in the industry or in the regulatory agencies. I was dismayed while helping review the California Title 25 ventilation policy that they wanted to DIS-incentivize H/ERVs because their field observations told them the installations were almost never done well enough to be confident in their long-term effectiveness. So, at that time, they incentivized bath fans instead. The ventilation industry definitely needs specialists.
Chris: Oh, that’s terrible. Disincentivizing good ventilation systems because of poor installation quality is the opposite of the correct response. They wouldn’t do that if electricians kept wiring electrical panels incorrectly. Codes shouldn’t lower themselves to skill level of workers. They should do better enforcement to raise the skill levels of the workers.
This month I virtually met Darren with Safe Air Pros in Chicago and he seems to be doing this very job, specializing in ERVs. I totally agree that there is a need here. For ventilation to work well the details matter!
Sophie: That’s great that there are a few companies becoming home ventilation specialists. We need many more.
I think the HVAC manufacturers should come up with integrated ERV’s and dehumidifiers that lower the cost and complexity of using them.
Bruce, I love the idea conceptually. While I worked at one of the top ERV companies I collaborated with a product development guy at one of the top dehumidifier companies to try to do exactly this. It seems logical because both functions involve blowing air around, and maybe through ducts. But their similarities end there. When it’s humid outside you want to decrease your big V ventilation air flow rate (outdoor air) and increase your dehumidifier’s recirculation flow rate. That’s the opposite response with air that wants to come from two opposite places. You could try to address that with extra fans and flappers and controls, but it doesn’t reduce cost or complexity. Next is the duct system. Any duct properly sized to handle the dehumidifier’s job anywhere in America east of the Mississippi in July is going to be way too big to effectively do the ERV’s job in January. Also the return air grills want to be very different places for those two jobs. These are all problems that could be solved with engineering, but not without adding more cost and complexity (for the mfg, the specifier, the installer, the owner, and the service tech). We concluded it was more effective to allow those systems to live in a separate but symbiotic relationship so they could both do their best work. But they absolutely should cohabitate in the same house!
I am building Pretty Good House made from SIP and ICF. The good folks at Build Equinox (CERV2) strongly suggested the Sophie Ashley from Energy Vanguard design the system. No surprise she did a great design and was a good collaborator. She improved on my original concept and simplified things—saved me money and headaches. She put the V back into ventilation. Being a retired engineer, I will be both the electrician and ductwork installer along with some hydronic work for radiant heating and cooling. Now if the heat pump guys would return my calls… but I will let Allison write a blog on that topic another time. (They don’t like properly sized systems).
Bill: Yes, Sophie is a great HVAC designer, including the V. As for the article you suggested, I wrote it in 2017:
The Contractor’s Fear of Third-Party HVAC Design
https://www.energyvanguard.com/blog/contractors-fear-third-party-hvac-design
Maybe it’s time to revisit it.
There is no doubt that the “V” in HVAC, especially in the residential market, is the most neglected and misunderstood aspect of HVAC. With the way buildings are being built today and the need for dilution air for IAQ issues, all of us in the HVAC industry need to focus a lot more on proper ventilation. Ruly 1 is that exhaust is only one aspect of ventilation that needs to be offset with controlled makeup air to balance building air pressures.
Tighter is better, right? Right?
I recently tightened up my house after electrification. We changed the gas dryer to a heat pump, so we blocked the dryer vent. We got rid of a furnace in exchange for a heat pump, blocked off those penetrations. We sealed off an unused chimney. Heat pump water heater. Two bath fans with flappers.
Now we are having trouble getting our powerful kitchen exhaust fans to draw like they used to. I’ve resorted to opening a nearby door to let in some makeup air. Doesn’t seem to be cutting it.
Many “dream Kitchens” have a commercial style gas ranges. Hardly any home cooks need so much fire power. Likewise, your powerful kitchen exhaust fan probably never needs to exhaust as much as you are. Commercial kitchens have dedicated makeup air within the range hood. You need to look into proper makeup air. Done correctly, it will only provide makeup air when the range hood is used. Considering the makeup air you were getting before blocking up other leakage points, there are a lot of reasons for not using them. An unused chimney sounds like a perpetually open leak point. If you were getting makeup air from the furnace, then it was a naturally drafting furnace that would backdraft when both the furnace and range hood were operating. Backdrafting the furnace sucks carbon monoxide into the house and if bad enough, potentially flame roll out.
Robert , you are correct about the furnace. It was a 2008 high effficiency unit which drew combustion air from a dedicated inlet. We switched from gas to induction so we have less waste heat. But we still have cooking odors. Those seemed to exit faster in the before times.
Our Vent-A-Hood doesn’t have makeup air. I”ve been thinking about adding a opening that can be controlled by relays tripped by the fan switches.
We have had success with recommending/installing simple passive makeup air systems. The simplest of which can be an exterior dryer vent with no flapper and a DIY added insect screen ducted into the basement via taught insulated ducting to a “heartland” style dryer termination with the accessory bath fan spring. By ducting this into the (usually) unconditioned basement (in climate zone 5/6) we temper the air with mother earth’s help and just make sure that the basement door is sufficiently undercut (it almost always is) to be non-restrictive. This will not do much to help overcome an oversized range hood but one can always use the lower settings or add a “fan in a can” wired to activate when you turn on the range hood if desired. Bottom line, if you’re installing a commercial”ish” range hood add makeup air just like the commercial folks.
Brian, great ideas, thanks!
Ventilation has long been overlooked in our industry, HVAC.
However, right now, it seems more important that we reduce the cost of building houses so that young people get a chance at home ownership. Every time we add new regulations we also add cost to the house. We are at a point where most people can’t afford to buy a first home. So while I agree with improving ventilation in homes, I disagree with adding more regulations to the building code that would require specializing ventilation. We’ve done fairly well over the years when airtightness wasn’t as critical. I believe ducted venthood need to a mandate for all homes and 50 cfm bath fans ducted to outside for all bathrooms.
The idea of having a separate ERV system in the house, though should be an upgrade not a requirement. I am aware of radon and have spent time working on humidity problems (mostly in hotels) but we have to realize we got to stop adding more and cost to building new houses.
From what I’ve seen over the last 40 years of working in the industry is that most people could care less about ventilation or even changing their air filters. For those that do care they’re going to spend the money later.
Maybe the best thing to do is just leave room for options and improvements when building houses but don’t require these upgrades.
IMO this issue revolves around incentives. Production builders are incentivized to pack as many bedrooms as possible onto the footprint of the house. This overly compact layout combined with the desired speed of construction does not afford a lot of room for a well functioning dedicated ventilation system let alone the HVAC system.
Minisplits can address some of these issues as the lack of ducting would leave room for a dedicated ventilation system but Americans aren’t fans of them.
My two cents.
I have never seen any guidance on designing a duct system for an ERV. Installation instructions show the near ducting to the AHU, which by inference suggests that this is the best way to do it. The duct picking up the exhaust from the house notes it should exhaust from bathrooms and utility rooms. There is nothing suggesting there might be an issue if it takes 100 feet of duct to get there and just maybe the ECM motor can’t handle that.
With major lack of knowledge of why the codes are requiring ERVs and no guidance from manufacturers as to how to install their product, there is small wonder the quality of installation is as bad as it is.
A timely plea. This ‘unclaimed niche’ is a massive opportunity for the HVAC industry to finally mature. Thank you for consistently championing the science behind the ‘V’.