So what gets better? The easiest way to understand the opportunity is to think about the heating and cooling system in our cars, which is pretty amazing, they tackle 5 of the 6 Functions of HVAC:

• Load Matching: We can put out just the right amount of heating or cooling by adjusting the air temperature and/or fan speed.
• Filtration: Every car has a good cabin air filter to knock garbage out of the air we breathe.
• Dehumidification: For the 80% of North Americans that live in a humid climate, we can knock the humidity out of the air with a magical button that says “AC”.
• Fresh Air: Our cars can bring in outdoor air which keeps, um, odors at a minimum and the air inside our cars healthier.
• Mixing: We can aim the air wherever we need it to keep us comfortable. It mixes in the cabin because the fan is always on, helping keep the temperature more even.
• Humidification: Cars can’t add humidity when the air is dry, but our homes can. 

Our cars can handle 5 of the 6 Functions of HVAC above, but most homes aren’t good at any of them. Check this short video out, or read the free HVAC 101 chapter to see why.

Getting These Isn’t That Hard 
There are many home HVAC systems that can provide those capabilities, it’s simply a matter of choosing the right equipment and install for your home and situation. 

3 of the 6 functions are directly related to what system you choose, the other 3 are related to the install itself. Here’s a look at what it takes to get the 6 functions.

A hybrid is a furnace plus a heat pump rather than a furnace plus an air conditioner. They give you more and lower stages of heat to provide better comfort. A heat pump is what we jokingly call a "bisexual air conditioner" - it can cool and heat, it goes both ways. 

​Check out the various equipment and install options below, you can pick and choose what’s important to you, but now you'll have a better idea of how to get your home HVAC to be as awesome as it is in your car!

You may have noted that I haven’t written anything about air quality monitors in a long time. 

Why? I was frustrated that there wasn’t a product that had the attributes I wanted, and also that there wasn’t a product that could do anything when pollutant levels justified action. 

That has completely changed recently with the Haven central air quality monitor and controller, which can actually take action from what it measures, and it offers the feature list I’ve been looking for.  We’ve installed them in several of our AirBnbs, this column will look at how we came to that conclusion and how it’s going early in the experiment. But first, let’s take a step back a few years and look at air quality monitors.

IAQ Monitor Must Haves
After spending a bunch of time with 7 air quality monitors in 2016 to try and learn what they’re capable of and which ones were better than the others, I came up with a list of 3 things that are must haves to deploy these in client homes:

• Dashboard - Remembering or storing multiple client logins and passwords is not a scalable thing, so I want to be able to easily look at any client anytime with one login.
• Fairly Reliable Readings - Low cost sensors in the $100-400 range are not going to have the accuracy of a $50,000 reference instrument, but I’d like to know that readings are somewhere in the ballpark of what’s happening.
• Four Metrics - Temperature, humidity, tVOC, and PM2.5. Why not CO2? Because most tVOC sensors are cross sensitive to CO2, so if tVOC levels are low, so are CO2 levels., The tVOC sensor picks up a much broader range of pollutants, so it is a better proxy for air quality. Read more on this in To Catch a Health Thief.

I really didn’t think this list was that hard to meet. Yet since the Foobot went off the market a few years ago, no room monitor actually met all of these. While there are plenty that are good for one off applications, none were a good fit for a pro who wants to monitor multiple homes with ease.

Frankly I gave up on monitors. We’d learned enough to come up with the BAD ASS HVAC design, which does a pretty good job automatically controlling air quality without any sensors or actually turning things on and off when a pollutant gets too high. Essentially, I gave up on the dream of truly controlling IAQ and moved on with my life.

Enter Haven

Having tried and eventually written off all room air quality monitors because they were lacking one of the 3 things above, I heard about the Haven Central Air Monitor. 

The Haven Central Air Monitor is different, it goes inside the return duct just before the filter. At first I didn’t like this about it, I’d grown used to room monitors. 

They have their own proprietary PM2.5 sensor that has remarkable accuracy in the lab. It measures 6 things:

• Temperature
• ​Humidity
• Airflow
• Pressure
• tVOC
• PM 2.5

Note the four things I want to be sure to measure are in there - temperature, humidity, PM 2.5 and tVOC. 

They also have a dashboard and their readings are generally quite good. I have a struggle with two of their humidity sensors, but the others have been on point, and most importantly the PM and tVOC sensors match events that I know of - cleaning, cooking, painting, etc. 

Room vs In Duct Monitors
There are two big problems with room monitors: clients unplug them eventually, and the sensors get dirty and out of calibration after a year or two.

While at first I didn’t like the sensor being inside the duct, that placement solved the customer unplugging them because the light annoys them. They can’t see it,  it’s out of sight, out of mind in the attic, basement, garage, or crawlspace. 

The sensors are easy to clean with a Q-tip or similar when changing filters and doing easy maintenance, solving the other main issue with room sensors. So the Haven solves the two primary weaknesses we found in in room monitors. 
I was intrigued. I now know most of their team, they are highly focused not just on selling products, but actually solving problems, and they also value technical excellence. But there was still a problem.

The Car Alarm Conundrum

Have you ever heard a car alarm going off in your neighborhood and thought “why don’t they turn that thing off?!” That’s essentially what indoor air quality monitors do - they tell you there’s a problem, but they can’t solve it. Basically they are annoying without offering a solution.

In the commercial world there has been “demand control ventilation” for years that monitors pollutants like carbon dioxide and can turn on devices to solve the problem. 

For homes we haven’t had a solution - until Haven came out with their central air controller last year. 
The Haven monitor talks to the controller when something is amiss with IAQ. Each controller has two dry contacts you can use to turn on the equipment of your choice. You can use multiple controllers with one monitor, so you can control 4 or even 10 different devices if desired. Conundrum solved?

Trying It Out: Haven + BAD ASS HVAC

Being an early adopter, I wanted to try out the controller with my monitor. This is something I wanted to try in one of our homes though, it’s early enough that I didn’t really want to try it with a client in case something went wrong. 
We recently moved to Fayetteville, West Virginia near the New River Gorge National Park. We bought two little houses next to each other (700 and 800 square feet.) We themed them, one is the Game House with board games and the other is the Candy Cottage which has a Willy Wonka feel. 

The Game House is done to the AirBnb specification I proposed in this column late last year - the bath fan and range hood are both vented outdoors, it has BAD ASS HVAC (with a standalone small dehumidifier for dehumidification), and a 14-50 plug for EV charging. I still need to figure out how to show guests what their air quality looks like. 
They both got 1.5 ton Daikin Fit heat pumps (another thing I wanted to try out.) 

The Fresh Air Strategy of My (Very Realistic) Dreams

Dr. Joe Lstiburek has talked about bringing in 50% of ASHRAE 62.2 guidelines all the time, then ramping up to 150% as needed. I really wanted to see how that might work in the real world. 
For a long time we’ve wanted to try out two fresh air ducts, one open almost all the time, and the other open when tVOCs/CO2 got too high. 
​
I’ll write about fresh air strategies soon, so for now please suspend your arguments in your mind about supply only, exhaust only, and balanced ventilation. These homes have a supply only strategy.
In each of the houses, I had two 6” ducts run from the HVAC return to outdoors, each with a motorized damper, see the photo. 

So I propose four rules:

• BAD ASS HVAC - cover the 6 functions of HVAC 
• Point source ventilation - range hood and bath fans vented outdoors
• Induction stove
• Air quality monitor - with results visible to the renters

The 6 Functions are: load matching, filtration, dehumidification, fresh air, mixing, and humidification. Depending on climate humidity control strategies may be different, but should be noted, i.e. “dry climate” for not having a dehumidifier or “warm, humid climate” for not installing a humidifier. The other 4 are required in every home though.

Those will naturally lead to inverter driven heat pumps, better comfort, and better air quality while being fairly easy to achieve. Because short term rentals have higher margins, it opens up room for these sorts of upgrades, particularly if HVAC in a property is at end of useful life.

Did you notice that I am not talking about shell measures here? If an owner is ok with high energy bills and potentially poor comfort in a home that is supposed to be comfortable, the reviews and energy costs will naturally drive that work to get done. 

Huge Leverage

A few thousand of these around the country could host 50-100 families each per year and give them the #electrifyeverything experience. 

Say there were 2,000 properties that host 50 families a year each. That’s 100,000 families a year seeing what the hype is all about. That is likely to spark many more full or partial electrifications and likely more #electrifyeverything short term rental properties. 

All of the homes would be substantially improved as well, which is good for US housing stock. These upgrades are likely to buy these homes an additional 30-100 years of lifespan by making them future proof and far more moisture resilient.

We’re putting our money where our mouths are on this, by the end of 2022 we will have 4 #electrifyeverything properties complete. The River House outside Cleveland needs central HVAC but does have an UltraAire XT155 ventilating dehumidifier for filtration, mixing, fresh air, and dehumidification. Our West Virginia house recently got a Bosch heat pump, it just needs a fresh air line and it’s complete. I’m currently figuring out how to electrify the two properties we just bought.
​
If it goes as projected by AirDna, a service that scrapes AirBnb data to help understand how homes in an area are renting and for how much, together these will create $40-60K/year of cash flow for us, enough that we don’t have to work if we don’t want to. (Although we'll likely use the money to create more of them…)

And there you have it, a path to solve for Doubting Thomases, let many homeowners experience comfortable electrified homes with excellent air quality, fix up properties that otherwise are likely to be neglected, and make money for the entrepreneurs who create the properties.

This could be like a brick on the proverbial gas pedal of residential electrification.

It’s also a surprisingly easy thing to make happen: AirBnb, VRBO, and other short term rental services can create an #electrifyeverything class. 

So, what are we waiting for? If you know someone at AirBnb or VRBO, perhaps send this post to them?

This position typically takes people by surprise. To be clear, I'm talking about single family homes in particular. Let's explore the details.

First off, definitions. A heat pump moves heat from one place to another. Your refrigerator is a heat pump. It takes heat out of the cold air inside and pushes it into your kitchen. The source is the cold air inside your fridge, the place it rejects the heat is into your house.

An air conditioner is technically a heat pump, it takes heat from inside your house and ejects it into the hot outdoors through something called the refrigeration cycle, but let's just call it magic, it's easier.

An "air source heat pump" in US parlance is an air conditioner that can heat as well as cool. I jokingly think of it like a bisexual AC, it goes both ways. Sometimes silly jokes like that stick. In winter it takes heat out of the cold outdoor air and puts it inside your house. Again, think of it as magic, but it's EXACTLY what your fridge does. 

A ground source (aka geothermal) heat pump takes heat from the earth through a long pipe loop that is either horizontally about 6 feet down in a large field like a septic field, or vertically several hundred feet down that takes up very little space in your yard.

The Question

Joel Zook in the Electrify Everything Facebook Group asked me my position on ground source for his older home in a very cold climate (Climate Zone 6, Wisconsin and Minnesota are the only states with substantial population in those zones.)

My Answer

That would be a place to consider them. My issue is that even after the tax credit they are typically $10-20K more. That $10-20K can usually make a good sized dent in shell work.

This client spent ~$35k on a ground source heat pump, which is about $25K after the tax credit. He had very high energy bills and an uncomfortable house.

He could have forgone the tax credit, spent $5,000 more out of pocket, got an air source heat pump and an insulation and air sealing package, then had very low bills and a comfortable house. 

Instead, he's using 21,000 kwh/year (total annual usage, not just HVAC). Our other clients with similar sized homes with air source heat pumps are using 12,000 to 15,000 kwh per year, and report that they are amazingly comfortable.

But thank goodness he was able to reduce his income tax bill!

His house is very uncomfortable AND uses more energy AND it cost more to do (both him and the government) AND costs more to run. This is pretty typical in retrofits, I've had several other clients in the same boat.

Remember, for $5K more he could have had a very comfy home that uses less and costs less to run. I hate talking about payback because it's the path to hell, but it would have saved him $700-1000/year in operating costs with an air source and insulation/air sealing path.

Ground source heat pumps are typically poor resource allocation. Money is limited, spend it wisely.

The exceptions are CZ6 and up, particularly in larger homes that are tough to reduce load on. The big risk is undersizing the loops or poor soil quality. It's distinctly possible to remove more heat in winter than gets replaced in summer and end up running on resistance a big chunk of the winter. Design and install are very finicky on ground source and there are very few contractors in most markets that can service them.

Electrification for you is likely to cost $20-30K extra with geo than it is with a hybrid furnace and air source heat pump. I question if that's worth it for what is likely a few hundred therms per year. I'd rather you use that money towards an EV or other high impact fossil reduction (even donating to causes.) Does that perspective make sense?

Market Distortions
Now I was on a rant, because this whole topic drives me nuts:

Some will talk about Dandelion now. NY is THROWING money at heat pumps, plus there is a 30% tax credit. Take those away and the economics of ground source are positively laughable.

The rule of thumb in policy is that beyond 1% market penetration, incentives get too expensive to continue. So we incentivize a few systems, build a small contractor network, then pull the rug out from underneath them.

I watched this happen with one geo company local to me in Cleveland. I drove by their shops over the years, they had a little one, got a really big one when the tax credit was on, then downsized again as the ground source tax credit came and went. I have several friends who got into the business with the tax credit, then got back out when it went away.

The same thing happens with efficiency/rebate programs. Robert Brierley watched 30 competitors die over the last few years when the efficiency program in Portland shut down. This same cycle happens with every program if you look closely. It's one of the big reasons we are so anti-program.

If a product or program isn't 100% sustainable without any incentives, it should die. Period.

Why? Because sooner or later the programs will die.

This is how we've built HVAC 2.0. It requires no programs.

​In fact, most programs make it harder for the 100% market based path, they subtly or blatantly shift the sales process or product selection, which kills closing ratios and job sizes. Programs turn contractors into tame bears just like signs at national parks say not to do. But then programs stop feeding them.

​This ends up messing up markets and preventing them from ever growing.

Because ground source requires drilling a loop for $8-20K AND the equipment is the same price or more expensive than air source, it will always need help to be first cost competitive in the market. Therefore it will die when programs are removed, which will happen at some point.

PLUS, even with that 30%, they still cost more and create the client situation I mentioned above, which I've seen multiple times.

If we want electrification to scale, products and business models MUST stand on their own. If they don't they will die like a tame bear when it stops getting fed in its cage.

This is a critical point. If we pull for anything that can't survive without help, we are destroying our future chances at decarbonization.

The path is VERY narrow, but there is one. We've built HVAC 2.0 around it.

Technical Improvements

One other key point: air source heat pumps have improved DRAMATICALLY over the last decade.

Ground source often made sense vs crappy single stage air source heat pumps. 

Now inverters have changed the game. While ground source remains marginally less expensive to operate, typically it's a few hundred per year difference where it could have been as much as a few thousand 10 years ago. Read HVAC 101 to understand the differences between single stage and variable speed/inverter HVAC equipment. 

Ground Source Favors the Wealthy

There is a lot of discussion about equity right now. Ground source heat pumps don't fare well here. First, they are primarily for the wealthy because a) they pay enough taxes to use the tax credits that come out of these projects and b) they are best applied to larger homes with high heat loads.

Are we sure we want to use large amounts of government money to subsidize a market that really shouldn't need subsidies?

For example, let's look at the project above. It generated a ~$10,000 tax credit. With the 3H (Hybrid Heat Homes) proposal, that same amount would buy 20 heat pumps that would reduce gas usage 30-50% for those homes, and they would be predominantly middle class homes. So that $10K can decarbonize one home or the equivalent of 7-10 homes. What is the better allocation of capital and fairness? This is a question that could use more discussion.

Conclusion - Do the Math

In most single family electrification retrofits, the first thing to do is insulation and air sealing. Especially in cold climates. That is often the best place to aim your money (leaving aside the fact that you are VERY unlikely to get it back at resale, another major market distortion.) 

If we want to decarbonize, don't we want to do it in the most cost efficient way that provides a great experience?

This is exactly what we designed the HVAC 2.0 process to do. 

It is built to find the best path for each homeowner's goals, what their house needs, and their budget. Will it occasionally involve a ground source heat pump? Yes. But likely in well under 1% of circumstances. There are almost always better ways to spend money.

If we want to see electrification move quickly, it needs to be done in the most effective and efficient way possible that also creates huge value. That way the majority of the market will do it. We've done this a number of times with our practice in Cleveland, and the HVAC 2.0 network has already done far more electrifications than we have with our small practice.

This system works on the ground and without any incentives or programs, which avoids the feeding the bears problem.

For us to come out with such a strong position against ground source should carry a great deal of weight because of our boots on the ground experience. 

Want a much deeper and nuanced view of what it takes to electrify your home? Take the free Electrify Everything course, a dozen emails with videos over several weeks to walk you through all the technical pieces of electrification (with a view towards marketing and scale.) 

Guest post by Griffin Hagle, originally written in 2015, edited slightly for 2021. 

Do you remember the first time you fired up a blower door after air sealing and nailed -- or exceeded -- your target number?

The exact moment may elude you, but the feeling is hard to forget. If you’re like me, you’ve pursued it ever since, and delight in the satisfaction of hard work captured in measured proof. The world faces some grave, complex problems. But it’s empowering to think that with such nifty tools and a healthy dose of elbow grease (or sealant) our efforts can be part of the solution.

That realization arrived for me in 2006. I had moved home to Oregon the year before, tail between my legs, from flight school in Oklahoma. Still reeling from 9/11’s impact on the aviation sector, the school closed, stranding me and scores of other students short of their sky-high dreams with loads of debt. I needed work.
I was so desperate that crawling under mobile homes sounded like a good place to start. 

Over the next two years, as an entry-level technician, I helped weatherize about 250 homes for a nonprofit community agency. One of my favorite memories was replacing a broken bay window for a single mother of four toward the end of a multi-day project. Through tears, she said it felt like an episode of a home makeover show, and gave each member of our crew a big hug.

I eventually moved on from that job, bitten hard by the building performance bug and sure there was even more good I could do helping others chase the feeling. 

Nine years after that, despite making modestly better wages for generally less messy work, the difference I wanted to make seemed harder to come by. As an ‘energy-efficiency mentor’ for a utility-funded rebate program in Southern California, I was on-call to resolve contractors’ issues within the program. Every now and then, I could see light bulbs come on as I took the uninitiated HVAC installer through duct-leakage testing procedures, or called an insulation crew’s attention to an overlooked air-sealing opportunity. Like the folks I worked alongside in my weatherization days, these were mostly earnest, hard-working people ready to do the right thing. 

The problem was, the principles and priorities of the system we worked within didn’t allow them to think in broader terms than the minimal effort needed to grab a rebate. In fact, it put limits on my own ability to show them the bigger picture. For example, I was free to explain the value per square foot of adding new insulation, or reducing duct leakage below an arbitrary threshold. But if I pushed back on, say, the use of utility ratepayer funds to cheer the installation of oversized fossil-gas furnaces in a climate among the nation’s most ideal for heat pumps, I did so at the risk of embarrassing my paymasters and ostracizing contractors trying to make a living.

That’s partly why, in 2015, I walked out on a promotion and moved 3,000 miles away to Alaska. 

I’m not alone

The year before I left, I connected with Nate Adams of Energy Smart Home Performance in Ohio. Nate, an early and ardent proponent of efficiency program reform, swung us an invite to the Forum on Dry Climate Home Performance in Northern California. It felt like a secret society (no, not in the Eyes Wide Shut way). Its independent-minded organizers threw themselves into hot rodding HVAC systems and building enclosures for pure learning and amusement, rejecting the world of sponsored products and dodgy energy savings claims. One of its founders, Rick Chitwood, co-authored one of the best field guides for performance contractors I’ve ever seen.

While there, I asked a contractor from the L.A. metro for his thoughts on rebate programs. He said business was so inconsistent he wouldn’t have been able to come had he not booked the trip months earlier. Common sense kept him out of the program. It just cost too much to keep up with it. Another contractor, from Orange County, put hard numbers to his cost of participation: on average, chasing rebates added $1,800 more per project. 

Other encounters that week reinforced the overall picture. The factors propelling growth in clean energy and electric vehicles clearly hadn’t materialized in the same way for home performance. (SolarCity, later absorbed into Tesla, found this out the hard way when it shuttered its two-year old energy-efficiency division in 2013.) A lot of the difference can be attributed to the sheer technical complexity of fixing up existing buildings, but an increasing share today comes down to whose ox is gored by policies centering cleaner, safer, healthier housing in the fight to reduce global emissions and solve climate change. Need proof? Look no further than the silk-glove tactics of the fossil gas and homebuilding lobbies.

It’s not about the energy savings

This might seem like a heretical statement to people who, like me, have given too much of their precious time away hoping to guide others onto a “greener” path. I’ve literally climbed uninvited into friends’ attics and driven hours to run pro bono air-leakage tests. Almost all of it was in vain.

The truth is that we’ve been failed by the narrative that the rest of society can be led to care as much as we do about what’s under the hood of their homes. Personally, I blame an outdated reliance on an earnest but naive brand of conservation messaging that arose in the 1970s and still shows up as “energy saving tips” in the junk mail of today. 
Renowned wonk Amory Lovins, no less vexed by the blithe tendencies that took our planet to crisis, has been saying for decades that the keys to managing our way out of it lie in grasping the everyday human impulses that drive energy production and use. People want “hot showers” and “cold beer,” not kilowatt-hours, air changes per hour, or avoided carbon emissions, no matter how politely they nod and smile when we drone on about them.

Case in point: my wife has become the best crusader for induction cooking I know. We’ve used a portable hob for two years in our poorly ventilated rental in Alaska and plan to install a slide-in unit in our upcoming home renovation. One of the bright spots of our pandemic year has been watching her gush to family and friends via FaceTime how fast it boils water, how precise and even temperature controls are, how it doesn't blacken our cookware, and how easy cleanup is afterward. I don’t need to mention that it curbs indoor pollution that commonly exceeds federal laws governing outdoor spaces or enables homeowners to break up with their gas utility. 

So, if the good people leave, who stays?

The six years since I left the grind of carrot-and-stick home performance have given me a bit of a wider view on subjects ranging from human nature to policy design. Alaska is also the perfect perch from which to observe and reflect on dynamics in the “Lower 48” from a distance.

Basically, good people want to be recognized for their good work. It is within our nature to seek acknowledgement and praise for our efforts. In clinical use, this is extrinsic motivation.

The designers of the program I worked or relied on extrinsic motivation by prescribing a value for certain outputs to get contractors to play along in their schemes. Some of these make more sense than others: $50 for a smart thermostat or $200 to swap out a pool pump. It gets trickier when assigning dollar values to whole-home measures that require a strong foundation in building science and a global view of project dynamics to execute successfully.
Enter intrinsic motivation. Most true believers fall into this category. The self-satisfaction of a job done well and confidence in their contribution toward a better world drives them in a way that sets them apart from the crowd. When coupled with extrinsic reward, however, including praise and pay commensurate with their efforts, the possibilities are limitless and people truly shine. 

It’s impossible to survive on intrinsic reward alone. At least not for very long. We all have bills to pay, and we do a disservice to our cause when we throw ourselves into work that’s not properly valued. It means little to honor good work, of course, without defining it. Nobody wants to stick it out in a hot, cramped attic doing their utmost for clients left in the dark by an energy-efficiency industry that won’t measure results that matter and hold practitioners accountable for them. (Nate’s had a lot to say on the topic of energy metrics to guide real estate out of the dark ages.)
Put differently, industries that don't track results don't draw excellence. In fact, they repel it. People who put in effort get discouraged and drop out, making space for mediocrity to flourish. 

I saw this firsthand at the annual contractor awards banquets the utility sponsored. The only people genuinely upbeat at these things worked for the big HVAC shops with cheesy TV jingles raking in rebate cash for doing more or less the same work they always had. It was depressing.

After years of that nonsense, you might think I’ve had enough to put this kind of work behind me forever. I’m certainly done with Big Energy Efficiency. But just as bad relationships can teach you about your personal standards, I’ve drawn enriching lessons from that frustrating period of my professional life. There’s also been organic growth in the residential electrification movement and encouraging shifts in consumer awareness and sentiment as the coronavirus continues to lay bare the deep risks hidden in a business-as-usual economy. 

There was an HVAC guy, Tony, I once met who enthusiastically signed each of his plenums in Sharpie, confident he had installed a zero-leakage system. He was an equal parts trade worker and artisan, the kind of person we need more of by the tens of thousands, nearly always hitting his mark. I often think about him and his style of work, hopeful current trends drive the kind of interest and innovation in the home performance industry that convoluted rebate programs never could.

If we’re doing it right, his should feel like the most rewarding job in the country.

Nate's Note
Griff has been a long time supporter of our efforts, which have now turned into the HVAC 2.0 program. I hope this view from inside the belly of the beast is helpful in showing that traditional utility programs are highly unlikely to lead us to scale in either decarbonization or insulation.

Unless both homeowners and contractors see value in better work, we're in real trouble. Done right, like Griff said, electrification and home performance work should be some of the most rewarding work out there. He's felt it. I've felt it.

Griff mentioned the critical word several times: value. Homeowners need to have problems to solve that are worth enough to solve that they can buy high likelihood fixes for those problems. That requires building value. It also requires contractors to believe that they can deliver those fixes and to ask for enough money to execute them profitably. 

Only then can anyone experience the satisfaction of an electrification or home performance job done well - it has to solve problems for homeowners and be profitable for the companies doing it.

Achieving those goals is exactly what the HVAC 2.0 program is built to do. 

Want to learn more? Read the free chapters on this site of The Home Comfort Book, check out case studies at energysmartohio.com, or better yet take the free Electrify Everything Course that will walk you step by step through what you need to know about doing these projects, then give you access to the HVAC 2.0 network that can help you do it.

Done right, a Big Ass Drop facilitates 3 of the 6 functions of HVAC - filtration, fresh air, and mixing. For the other functions we have other tools which we’ll discuss in the rest of the series.

Links To Prior Articles: 

Part 1 tackled load matching and filtration. 
Part 2 looked at dehumidification and how it’s the lynch pin to healthy homes in many climates. 
Part 3 dug into fresh air and how we may not need as much as the standards suggest, which allows for the simpler system we’ll be discussing this time. 
Part 4 tackled Mixing (right place at the right time) and humidification.
​
Health - The Main Benefit of The Big Ass Drop 

One main reason for using a Big Ass Drop is reducing health risks. We breathe about 3000 gallons of air per day, at least 2700 of them indoors, and most of those 2700 inside our homes. This is something most of us can have direct control over.

As we covered in part 1, the fine particles that get into our lungs and blood can have substantial health effects. Collectively, particulate matter will take about 2 years off each one of our lives. Two examples of this are diesel soot, which contains a lot of heavy metals in very small particles, and viruses, which often travel inside small spit droplets. 

By reducing how much garbage our bodies have to filter out, good filtration helps improve our respiratory health and make us more resilient to infections, allergies, and asthma. If you want to learn more, here’s a list of air quality researchers I follow on Twitter.

Client Feedback - Some Things Installing a BAD Improved In Their Lives

• Allergies and Asthma: “When allergy season is in full swing, going inside is a refuge.”
• Less Cleaning: “I notice I don’t have to dust as much”.
• Help Fix Hot/Cold Rooms: “Sally’s hands don’t turn blue in the mornings”
• Sleep Better: “We sleep through the night.” In part 3 we talked about carbon dioxide levels. The ideal levels are 500-800 ppm of CO2, but many bedrooms get over 1000, some get to 2000. This leads to poor sleep. By mixing the house, which is inexpensive to do with a BAD and an efficient fan, you can even out the entire house so that you sleep better with lower carbon dioxide levels.

What Does a BAD Look Like?

First, let’s look at what a typical return drop looks like, this is what the system at the beginning of the article looked like before we changed it: