As we prepare to welcome a new decade, let’s take a look back at the key clean building technologies that began to emerge in our industry — and that may be critical to our health and wellbeing in the future. Most of these innovations are decades old — but have been refined, developed, popularized and commercialized in recent years. They are increasingly making a positive impact against greenhouse gas emissions, ozone depletion and water pollution. 

I did not include compromise technologies such as hybrid heating systems, refrigerant blends or biomass, designed mostly to help people accept or sell change. They are legitimate efforts, but scientists suggest we don’t have time to keep finding ways to delay the shift away from destructive tech. This means compromise systems become part of the problem, not part of the solution.

Each technology is assigned a rank for its importance. Of course, that’s an arguable exercise both in the details and the value. Some are important because of the energy and greenhouse gas savings they have already achieved; some because of their potential or my prediction that they continue to contribute to the industry significantly; and some because they are dramatically cleaner or more efficient than conventional systems.

1. Passive house. Passive house has been proven to save 80 percent or 90 percent on energy wherever it has been used. However, because there are only a few thousand projects across the continent, we haven’t yet seen the big-picture impact that I expect we will see. 

Passive house is both a tool (the standard) and a set of required or strongly suggested technologies. Whatever you might think of this approach, it works. There are the strict German version and the PHIUS version. I prefer the former to the latter. (Please send any strongly worded objections to bruce.nagy@rogers.com.) 

It is now being adopted by architects, engineers and planners worldwide as they face aggressive new requirements from municipal governments that seem to be at the forefront of the effort to improve life on the planet.

LEED, passive house, net-zero, WELL and many other standards have their strengths and weaknesses, but there is no denying their role in the past 10 years as valuable tools to guide progressive builders toward cleaner systems and higher energy and water efficiencies. I believe LEED did the best job as a green building brand in the early days, but the sustainable construction industry is now moving toward outcome-based standards such as passive house — as well as becoming more interested in embodied carbon models.

For me, passive house and WELL symbolize the ideal umbrellas for:

• A host of building envelope technologies such as continuous insulation, triple-pane windows and air curtains, which address the poor energy retention of the past.

• Indoor air quality improvements, including low-VOC paints, coatings, sprays, materials, plant walls and HEPA filters.

• Low- or no-emission mechanical technologies, many of which are found in this listing.

2. Heat pumps. Electric, refrigerant-based heating and cooling equipment such as air-source heat pumps and commercial variable refrigerant flow (VRF) air-source systems have already significantly penetrated the North American market. 

Their forward momentum cannot be arrested due to their improving capabilities, broadening applications, a quickly shifting regulatory environment and, increasingly, their economic advantages. They will soon become a dominant conditioning device in North America, as happened previously in Europe and Asia. 

Characteristically, the process in North America has been accompanied by product improvements because it was the only way for manufacturers to overcome objections and the inevitable resistance to change. Air-source products now perform well in more extreme climatic conditions and offer sophisticated electronics and Wi-Fi capability. 

Sanden and Mayekawa also are beginning to see success with large-capacity air-source systems that employ carbon dioxide and ammonia refrigerants.

Ground-source and water-source heat pumps may not have changed as much as we might have expected; however, some of the installation practices and system designs are creating a long-sought economic, more compact geothermal system. 

Also, as a highly viable clean energy replacement for fossil fuels for the most significant heating and cooling loads (especially northern heat), geothermal is being recognized and supported by governments, funding bodies and financial institutions more than ever before. Also, research organizations continue to test ground-source technology options that attack the system cost equation.

3. Electronic, computerized, Wi-Fi-enabled devices. Intelligent and connected devices create undeniable customer conveniences and also help designers, building operators and homeowners to save energy, water and money. They include smart thermostats, energy monitors and smart home systems, HVAC and plumbing equipment and pumps with intelligent capabilities, Wi-Fi monitoring and data storage. 

The digitization of virtually every machine on earth is not a fad, the benefits are real and the impact is often underestimated.

4. Variable-speed equipment. Digital capability has usually enabled variable-speed equipment. Electric VRF heat pumps, variable-speed pumps, variable-speed fans and variable-speed ECM motors are achieving dramatic energy savings, which is essential wherever utility power generation employs fossil fuels. 

By now, variable-speed equipment should be a standard choice in almost every application. And yet, it is not always chosen, even when the case for doing so is highly compelling. It’s a mystery.

5. Natural refrigeration systems. If this list reflected the world’s highest priorities, using natural refrigerants might be found even closer to the top. As we know, HCFCs damaged our ozone layer and HFCs contribute to global warming. Thankfully, we have made an impact with our HCFC efforts — the ozone hole has stabilized and, despite a few hiccups, is probably on the road to recovery. 

Refrigeration and air-conditioning equipment using natural refrigerants C02, ammonia propane, air and H20 are now well-proven and being implemented all around North America in grocery stores, arenas, refrigerated warehouses and freight trucks. There is a lot of noise in the space, so it’s crucial for today’s air-conditioning and refrigeration professionals to do their homework and make good choices. I have case studies if you’d like more information.

6. Energy recovery equipment. Heat recovery ventilators, energy recovery ventilators, conditioning energy recovery ventilators, refrigeration heat recovery, data center heat recovery — all have the potential to reduce fossil-fuel use within a building or within a power grid. When considering contemporary design models and budgets, they also can be the contributor that makes a particular goal achievable.

7. Radiant hydronic systems. Radiant hydronic delivery systems using radiators, chilled beams, underfloor or slab systems support peak-shaving strategies, better indoor air quality and increased efficiency compared with forced-air options. As load calculation and system sizing has become more precise, and as buildings are better insulated, there has been a resurgence in the use of radiant hydronic systems. Liquid moves energy better than air does.

8. Water heat energy recovery equipment. Heat pump water heaters, sewage heat recovery and drain water heat recovery are the under-the-radar workhorses of the energy management landscape. The savings always surprise me and reveal what humans can achieve when they change their goals and choose to be creative. 

Closely related are technologies designed to be more efficient, such as tankless water heaters (not really a recovery technology). Although the up-front cost for tankless water heaters is still higher than a conventional tank system, they are becoming more popular and more affordable. If system life and operating costs are factored in, perceptions change. Tankless technology is about 25 percent or 30 percent more efficient. I’ve seen a few instances in which it is also used for space heating.

9. Water conservation equipment. Water pollution is a huge problem; water infrastructure in cities and towns is yet another. They are why the cost of domestic water service and sewer services in municipalities keeps zooming skyward.

Low-flow, electronic and waterless plumbing fixtures help address the municipal capacity/cost problem that is often a fundamental cause of pollution and a mitigating factor for faster healthy infrastructure upgrades.

Similarly, water re-use systems that collect and treat rainwater, greywater and black water help to alleviate capacity and regulation constraints.

These are accompanied by advanced localized water purification systems such as membrane and UV filtration, which can contribute significantly to addressing these problems.

10. Rooftop solar, portable/home batteries and microgrid software. Again, these technologies could easily be placed near the top of the list, in terms of reducing emissions during the 2010s and their massive potential in the coming years. More and more it appears the electrification of buildings and the distributed energy revolution are not just real, but come with numerous advantages, including some that were perhaps less expected.

The costs of localized electricity generation and battery storage have been dropping so quickly that most of us are not well-informed on the latest developments. Additionally, the efficiencies of both can still theoretically increase by several orders of magnitude, forcing the use of the term “gamechanger” in terms of conventional definitions of energy systems in the built environment. As we know, money makes the world go ‘round — it also delineates innovation roadmaps.

A parallel efficiency is the emerging software-enabled energy shifting between vehicle batteries, home and business batteries, and utility-scale electricity operations. As local governments, research bodies and start-ups continue to tackle this field jointly, it’s moving quickly from the theoretical realm to actual operating systems in every progressive city in the western world. 

And because it’s all digital and monitored, with full instantaneously available data (and often some top-drawer quantum computing-powered artificial intelligence), real-time results quickly erase any hand-wringing about whether it works. 

In the 2020s, a powerful adoption driver of portable batteries and microgrid software for businesses, institutions and homeowners will be the opportunity for peak shaving to save time-of-use charges. I predict that by the end of the decade, the opportunity having paid off handsomely, will disappear because the utility power model will have changed drastically. There will be no such thing as time-of-use charges or capacity challenges.

Outside the Built Environment

Outside of the built environment, the decade’s critical technological developments include the progress made with electric transportation and with renewable electricity generation and storage at utility-scale. As regular readers know, I never tire of pointing out that buildings, transportation and power generation are responsible for 70 percent to 75 percent of the world’s polluting emissions.

At the top of the transportation emissions list is personal private transport — electric cars, SUVs and pickup trucks. In the 2010s, they have, so far, made minimal emissions impact, but are finally breaking through and destined to go mainstream. It’s much like the inevitability you could feel in the early days of smartphones. 

The sales explosion and industry chicanery of the last few years indicates that the only question left is how fast will they replace internal combustion products everywhere. Electric commercial and freight vehicles, trains, buses, drones, ship and electric airplanes also are taking off.

Just as distributed or rooftop solar outperformed expectations, wind, solar, and utility-scale storage have completely obliterated coal, gas and nuclear power generation on cost (and emissions). Power companies all over the country, and across the globe, keep accelerating adoption schedules because renewables continue over-delivering on their advantages, and proving much easier to implement than people are continuously (and deliberately) led to believe.

Again, wind and solar are a big story on their own, but we must not overlook the pervasive impact coming from electricity storage advances, and smart grid software for utility load management and cybersecurity. 

People think of lithium-ion batteries when it comes to electricity storage, but the innovation playground is broad and also includes compressed air, pumped hydro, flow batteries, flywheels, solid-state and sodium-sulfur batteries, thermal storage, gravity storage and hydrogen fuel cells. Some of the costs and strengths of each kind are well-established, while others are evolving because the field is attracting massive amounts of research and development investment. 

The lines are about to blur between electrified buildings, cars and batteries — electrified lives. It’s all merging into a new era: rooftop solar/small wind, community microgrids, district building energy and creative future service offerings from utilities.

Not only has the clean energy age thrust itself into the limelight during the 2010s, but it has done so with good reason: There is no time left to lose to address the crisis of unhealthy worldwide pollution. The global innovation environment has reached a feverous pitch, setting the stage for the 2020s to become a golden age for human ingenuity.

 Happy holidays to you and your loved ones, and best wishes in the new decade.