Spotted: Data centres are a significant but often overlooked contributor to climate change, responsible – along with their accompanying data transmission networks – for around one per cent of global greenhouse gas emissions. Computer processes generate a lot of heat as a by-product, and cooling systems therefore account for a significant proportion of the energy consumption of a typical data centre.
Now, however, French startup Hestiia is looking at the heat generated by computing differently, using it to create a new kind of domestic radiator, called the myEko.
The startup collects and upgrades used ASIC chips from data centres and places them on a custom-made electronics board, which forms the core of the radiator. Conductive layers and piping then transfer the heat produced when the refurbished chips perform calculations to the space that needs heating.
Hestiia provides the compute capacity embodied in the radiators to companies that need it for heavy workloads such as scientific research, 3D modelling, crypto mining, and blockchain. The startup’s customers, meanwhile, install the radiators to heat their homes.
In addition to being highly efficient, the radiators use smart sensors to automatically regulate the temperature of a room, and users can tweak preferences on the app, such as setting day and night modes to automatically adjust temperatures for each space depending on the time of day. And, the system further detects temperature changes from actions such as opening a window and alerts owners, signalling them to turn the temperature down to avoid wasted energy. In ‘geolocation mode’, the system can detect when a user is coming home and turn on the heating accordingly.
Hestiia’s initial product was a water heater system called SATO that similarly reused the heat from computer chips to supplement a standard boiler. The startup is now pivoting to focus on myEko, which it believes is an even more accessible, mass-market solution.
Other innovations in Springwise’s library working to decarbonise computing include a new power distribution unit that maximises efficiency, and the use of AI to reduce the number of calculations required.
If you’re interested in shaving off perhaps 10% of your household energy use (and your electric bill) with a single purchase, it’s time to look into heat pump clothes dryers. “An electric dryer can use anywhere from 700 to 1000 kilowatt-hours of electricity each year. That’s about a tenth of the average American’s electricity usage,” said Joe Wachunas, electrification advocate for Electrify Now and Project Manager at New Buildings Institute. “You can cut that by 75% or more using heat pump dryers.”
With options on the market that use as little as 200 kWh of energy in a year, it’s not hard to see why their market share is increasing. “Heat pump technology is critical here in America, especially,” Wachunas says. “And heat pump dryers are an exciting, relatively new technology.”
Traditional vented dryers
Vented dryers can be either gas or electric, and they require venting to the outside of the home through ducts. A heating element heats the air in the drum, evaporating the moisture from clothes. Then as the dryer runs, the hot, moist air is vented outside and replaced with air pulled in from your laundry room, basement, or wherever it’s located. This influx of fresh air must be heated to continue drying the clothes.
Ga-Young Park, Residential Appliances Manager at ENERGY STAR, pointed out another inefficiency. “Because vented dryers pull in cooled or heated air from your home and vent it outdoors, your air conditioner or heater has to work even harder to maintain the indoor temperature.” Also, vented dryer drums get very hot during operation, which—aside from the fire risk—can overdry clothes and potentially damage fabrics.
Heat pump clothes dryers
Electric-powered heat pump dryers (aka ventless or condensation dryers) dry clothes without using a heating element or vent. Instead, heat pump technology pulls air into a condenser, heats it, and sends it into the drum, where it absorbs moisture from the wet clothes. Then, the air cycles to an evaporator, where it’s cooled. As the air gets colder, it loses moisture, which is either drained or collected in a removable tray.
That same air is then pulled from the evaporator into the condenser to be reheated while it’s still warm. In other words, heat pump dryers recycle warm air instead of venting it to the outdoors. Not having to heat fresh, cold air leads to big energy savings. Park added, “Heat pump models dry laundry at lower temperatures, which is much gentler on clothes. And unlike vented dryers, there’s basically no fire risk.”
Hybrid heat pump dryers
Hybrid heat pump dryers combine the heat pump cycle with the heating element of a vented dryer. This pairing helps the dryer drum get hotter, so clothes dry faster. Hybrid heat pump dryers are much more efficient than vented dryers, but because of the heating element, they’re less efficient than pure heat pump dryers.
Bosch WTG86403UC 300 Series 24 Inch Smart Electric Dryer, ventless. Images courtesy Amazon.
Size, price, and dry time
“People often think heat pump dryers take way longer to dry clothes because they use lower temperatures,” said Park. In reality, heat pump models can have dry times comparable to many vented dryers on the market today. All models with the ENERGY STAR label meet an 80 minute maximum dry time for a “typical” cycle, and some newer models demonstrate dry times as low as 50 to 35 minutes.
Historically, heat pump dryers have been compact in size, smaller than typical US household dyers. Things are changing, though. Park reported only ten options for standard-size dryers with heat pump technology, but expects that more standard-size heat pump dryers will continue to come on the market, particularly as hybrid models become more available.
Heat pump dryers are definitely more expensive than traditional vented dryers, but more and more, utility-sponsored rebates are available to offset the cost differential. Owners may also save on installation. Heat pump dryers do not require venting ductwork, which makes them simpler and less expensive to install. Homeowners can install the dryers nearly anywhere, provided the condensed water is allowed to collect or drain along with the washer.
Of course, you’ll also see major savings on your monthly energy bill.
Finally, the Inflation Reduction Act (IRA) will provide additional rebates and tax credits for homeowners looking to make energy-efficient home upgrades. (This savings calculator can help you estimate how much money you can save on a heat pump dryer through the IRA.)
Note: European households use an average of 3,700 kWh of electricity each year, just a third of what Americans use. Not coincidentally, while most of the world saves big money and energy by hanging clothes outside to dry, the practice is restricted or completely banned by many communities across the United States!
ENERGY STAR’s 5 Most Efficient Dryers
ENERGY STAR, run by the US Environmental Protection Agency, has overseen testing and labeling of quality, energy-efficient products for more than 30 years. The blue ENERGY STAR label signifies brands and models that are leaders in energy efficiency.
ENERGY STAR ranks dryers based on their Combined Energy Factor (CEF), a measure of energy efficiency. The higher a dryer’s CEF, the more energy efficient it is.
This article springs from Electrify Now’s webinar on Heat Pump Dryers. Their followup, Heat Pump Dryers – Update on Brands and Options, compares units from Bosch, Miele, GE, and LG:
The author:
Catherine Poslusny is a freelance writer and content marketing specialist based out of Norman, OK. You can find her at catherinerosewrites.com.
The word is now out, and sales of heat pump water heaters (HPWHs) are taking off. New rebates, mandates, and tax credits will likely drive sales through the roof by the end of this decade. Heat pump water heaters use a fraction of the energy of legacy technologies, with great performance, which means lower utility bills along with reduced carbon emissions. We’ve embraced the technology on our journey to electrify two different properties, and we were among the first in the US to buy and install a 120V plug-in heat pump water heater at our family home in Ohio.
Why do we sing their praises?
Cost!
The heat pump water heater is among the most affordable climate-saving technologies available. While solar panels and electric cars are vital tools for climate warriors, a heat pump water heater saves the energy equivalent of seven solar panels while costing only one-sixth the price. They run approximately $1600 for the appliance, plus $1000 to $3000 for installation, depending on the fuel your current water heater uses. This cost is higher than traditional gas or electric-resistance water heaters, but many utilities offer rebates to bring down the price. And then add the 30% tax credit from the Inflation Reduction Act, if the property is your primary residence.
If your current water heater is gas, you may need to run a 240V electrical line, unless you get a new 120V plug-in model (for more info on this option, read about our fourth install below). If your current water heater is electric-resistance, it should already have a 240V line running to it, likely allowing a simple swap.
Efficiency
Hot water accounts for a substantial share of energy use in buildings—17% in single family homes and up to 32% in multi-family—hundreds of dollars a year. Heat pumps move heat rather than create it. So heat pump water heaters are three to five times more efficient than standard water heaters. They look just like a legacy water heater, but a bit taller because the heat pump sits on top of the water tank.
Sure heat pump water heaters are super energy efficient, but they also run on electricity, which means they can use renewable electricity. Replacing a single gas water heater with a heat pump unit will save around 1 ton of CO2 annually.
And the word is out. While heat pump water heaters currently account for only less than 2% of new water heater sales, they jumped 26% in 2022 as sales of natural gas water heaters fell. Heat pump water heaters could increase to half of all water heater sales by 2030.
Propelling electrification
Electricity is the only widely-available, scalable fuel option that is quickly decarbonizing. So reducing climate change involves converting everything to highly efficient, clean electricity. A common critique of the electrification movement is that the electrical grid can’t handle the additional loads to replace fossil fuels used in buildings and transportation. Enter heat pumps. Widespread deployment of heat pumps in HVAC and hot water production will save tremendous energy: enough to power new electrical loads, like electric cars (EVs), on the existing grid.
Heat pump water heaters (HPWH) will likely save nearly all the electricity a household needs to operate an EV.
As Americans transition to EVs over the next decade, heat pump water heaters alone will likely save nearly all the electricity that a household needs to operate an EV. This statistic shows how much energy we currently waste in heating our water. And this EV electrical load is replacing carbon-intensive gasoline and diesel fuels.
About half of the US currently has electric resistance water heaters, so as those homes switch to heat pump water heaters, we won’t have to worry about finding more electricity for EVs. Their utility bills will likely stay constant, saving them all the money they currently spend at the gas pump.
The other half of homes heats water with fossil fuels, so we will need to find added clean electricity for those water heaters and vehicles. (But transitioning electric-resistance space heaters and clothes dryers to heat pump units produces savings similar to switching out water heaters.) Most heat pump water heaters run on 240V (the same as conventional electric water heaters and dryers), but if your old water heater runs on gas, you may have to install a new power line from the panel. But a 120V plug-in model is the newest option. If your current water heater is electric, it will likely be an easy swap: no need for an electrical panel upgrade or service upsize from the utility.
2017: HPWH replacing an aging water heater
Our old gas water heater was nearing its end of life, and Joe was excited about the technological advance of heat pumps for water heating. Though we still had questions about installation and performance.
It’s easiest to install a heat pump water heater in a basement or garage, because they exhaust cool air. But our heat pump water heater resides in a coat closet in the middle of our living space, venting into the attic. There it draws the warmest air in our house and exhausts to an unconditioned space. (Note that there are lots of options for locating heat pump water heaters in living spaces without ducting.)
Of course there were no local installers familiar with heat pumps back then, but after watching YouTube, Joe felt OK working with a trusted handyman. Even though it was a gas conversion, an existing 240V electrical line made things much easier. Ever since, this unit has consistently provided our family plus an Airbnb with plentiful hot water.
2019: HPWH replacing a functioning gas hot water heater
We did not get the full life out of the existing gas hot water heater in the accessory dwelling unit on our property. We chose to replace a perfectly good appliance (only 7 years old) with a heat pump water heater powered by clean solar energy. Our goal was to eliminate fossil fuels from our home. We used the same attic-ducting technique as the water heater in the main house, locating the unit in a closet. This mighty unit provides plenty of hot water for the tenant and runs the radiant floor heating system as well. (We don’t recommend heat pump water heaters for floor heating, as it is not a proven or scalable application.)
2020: HPWH replacing a decrepit gas water heater
During COVID, we undertook an interiors and sustainability renovation of a duplex in Cleveland, OH, that has been in our family for 75 years. In transitioning to all-electric, we replaced an almost 30-year-old basement water heater with our favorite heat pump. In addition to reducing our energy bill by $200 a year, it provides great dehumidification: about 2–4 quarts of water per day. If you currently run one or more dehumidifiers in your damp, Midwestern basement, you may save hundreds more.
The plumber added a new 240V power line, and ran the condensate tube to the floor drain. The basement maintains about 60 °F all winter, and we’ve never needed to engage the less-efficient backup electric-resistance heating elements.
2023: The new 120V heat pump water heater
This past summer, we replaced the other 30-year-old gas water heater in the basement of the Cleveland duplex. This just-arrived-on-the-market 120V unit eliminated the need to run 240V power from the panel. As heat pump enthusiasts, we were excited to test the latest tech. Perhaps the most difficult step was placing the custom order with Home Depot. Though now it’s readily available!
The installation was the easiest part. It took the plumber (who had never heard of a heat pump water heater) only 2.5 hours to complete the job, about the same as a standard gas water heater. The 120V heat pump water heater plugs right into a standard outlet. But he did have to run the condensate tube into the floor drain nearby and cap the gas line.
The 120V unit has been humming along for months—it’s very quiet—using a mere 65 kWh in the first month of operation. We monitor its performance through the manufacturer’s app, so we know it remains ridiculously efficient and almost always completely full of hot water. At a total of $3,258 installed and estimated savings of $208 a year. The 120V models usually eliminate the backup electric-resistance heating elements by using a larger tank with more hot water stored, or by storing water at higher temperatures and then mixing in cold water to avoid scalding. Our 120V unit uses the latter strategy; see it in action.
If this were our primary residence, we might have taken advantage of the 30% tax credits for heat pump water heaters, lowering our cost to $2,281. That comes so close to the $2,000 average installed cost of a standard gas or electric water heater. And you’re still saving hundreds of dollars a year on energy costs. This proves that almost any of the 60 million US homes with a gas water heaters can easily and cheaply move towards a cleaner, decarbonized home that is less expensive to operate.
We’re big fans of making a long-term decarbonization plan, so you’re not rushing to replace broken equipment and being forced to install new circuit breakers or even a new panel or expensive electrical service upgrade. So before checking the cost of a heat pump water heater, understand your home’s installation requirements and identify a contractor or two. Then when the time, and rebates and tax credits, are right, you’re ready to switch. Because they save so much on utility bills, proactively replacing a functioning, but inefficient, water heater with a heat pump water heater may make sense—for the sake of our changing climate.
This article springs from several posts by Naomi Cole and Joe Wachunas, first published in CleanTechnica. Their “Decarbonize Your Life” series shares their experience, lessons learned, and recommendations for how to reduce household emissions.
The authors:
Joe Wachunas and Naomi Cole both work professionally to address climate change—Naomi in urban sustainability and energy efficiency and Joe in the electrification of buildings and transportation. A passion for debarbonization, and their commitment to walk the walk, has led them to ductless heat pumps, heat pump water heaters, induction cooking, solar in multiple forms, hang-drying laundry (including cloth diapers), no cars to electric cars and charging without a garage or driveway, a reforestation grant from the US Department of Agriculture, and more. They live in Portland, OR, with two young children.
With 45% of urban areas covered by pavement, climate change is pushing cityscape temperatures to record highs. Innovative, sustainable pavement solutions are urgently needed. Whether used with asphalt or conventional concrete, “cool pavement” solutions, such as ePAVE, can decrease the urban heat island effect by mitigating greenhouse gas emissions and reducing heat absorption.
While on a vacation in Europe, after being seated for dinner with friends at an outside table at a popular restaurant, we could all feel the intense heat emanating from the asphalt nearby—even though the sun had set hours earlier. This scenario has become all too common and is being repeated in urban centers all over the world.
Across the planet, asphalt contributes to significant greenhouse gas emissions. Asphalt pavement absorbs solar radiation and re-emits the radiation as heat, warming the surrounding air and structures. This results in an escalating use of air conditioning (which further adds to outdoor heat) and drives up energy consumption. Due to high heat retention, darker asphalt surfaces are a major contributor to the urban heat island phenomenon.
During a day with a comfortable “ambient” temperature of 75° F (24° C), asphalt surface temperatures in full sun can rise to 125° F (52° C) or higher! Along with the significant heat emanating from the asphalt, comes an increase in toxic emissions into the environment.
How CoolPAVE works
The CoolPAVE coatings from ePAVE reflect some solar radiation, so the pavement stores and emits less heat. Safe and cost-effective, ePAVE’s cool pavement solution also seals in toxic emissions from underlying surfaces. Further, ePAVE solutions enhance the durability of treated pavement surfaces, extending their lifespan.
ePAVE products work on new and old, asphalt and concrete surfaces. Trained applicators prepare the pavement surface (minimally) and then apply the CoolPAVE product cold. It cures quickly and is ready for foot and vehicle traffic in about an hour, which keeps closures and delays to a minimum.
ePAVEproducts are tested and proven to lower surface temperatures by 5–20° F. In summary, this non-toxic pavement preservation solution with high solar reflectance impacts three key remits:
Human: ePAVE solutions make cityscapes cooler and more hospitable for people and their pets, by making streets and neighborhoods more walkable, livable, and equitable. Mitigation of urban heat islands is expected to reduce the incidence of heat-related illnesses and deaths.
Environmental: the ePAVE cool pavement product makes communities cooler, thus lowering toxic emissions and energy consumption. Overall cooler ambient temperatures can reduce heat-related stress on urban habitats.
Economic: CoolPAVE can save energy and those associated costs, and may extend the lifespan of treated pavement by up to twice as long as standard pavement treatments, requiring less frequent repairs and reducing maintenance costs.
ePAVE solutions are nontoxic and free of volatile organic compounds (VOCs). ePAVE seals asphalt surfaces, preventing outgassing and leaching of harmful chemicals into the environment via stormwater. ePAVE may also contribute to LEED certification. Under Sustainable Sites, up to two points can be earned for impacts on the Heat Island Effect.
USGBC-LA Net Zero Accelerator
ePAVE, LLC joined the 2020 cohort of the Net Zero Accelerator (NZA) to benefit from learning from subject matter experts in marketing, business development, and networking. The NZA, a program of the U.S. Green Building Council–Los Angeles (USGBC-LA) focuses on piloting projects in real-world, trackable implementations, to drive measurable adoption of net zero solutions, today.
Since its founding in 2018, the accelerator has guided the success of 85 growth-stage companies in the cleantech and proptech space across the US and Canada. The program bridges the gap between net zero building policy and current technologies in use in both commercial and affordable housing sectors. The NZA builds awareness of viable solutions and market-ready innovations through marketing, media, events, and curated networking. Then shepherds the tech to market through onsite pilots with committed green building leaders, accelerating scaled adoption. The goal? Make net zero carbon, energy, water, and waste a reality for Los Angeles and beyond.
The author:
Klara Moradkhan is Co-Founder and CEO of ePAVE, LLC. She is passionate about building a sustainable and eco-friendly pavement solution that fits the 21st century.
Spotted: At present, global food security relies on the use of nitrogen fertilisers, but their production and use are responsible for around five per cent of global greenhouse gas (GHG) emissions, along with pollution and soil depletion. One possible solution is to use bacteria that convert nitrogen gas to ammonia to provide the nutrients that plants need and regenerate the soil. However, these bacteria are sensitive to heat and humidity, so it’s difficult to scale up their production and use.
Now, researchers at MIT, led by Ariel Furst, the Paul M. Cook Career Development Assistant Professor of Chemical Engineering, may have a solution that could remove this limitation. They have devised a metal-organic coating that protects bacterial cells from damage without affecting their growth or function. The coating contains food-safe metal and polyphenol compounds, and can self-assemble into a protective shell.
In their study, the researchers created and tested 12 different coatings. They encapsulated a nitrogen-fixing bacterium that also protects plants against pests. All of the coatings protected the bacteria from high temperatures and humidity and improved the seed germination rate by 150 per cent compared to seeds treated with uncoated microbes.
The research received funding from a number of sources, including the Army Research Office and a National Institutes of Health New Innovator Award. Furst has also launched a company called Seia Bio to scale up and commercialise the coated bacteria.
Regenerative agriculture is gaining steam, as farmers realise that it is not only more sustainable but also less costly. Recent innovations in regenerative agriculture spotted by Springwise include a company rejuvenating exhausted soils using bacteria and solar-powered trackers that help farmers efficiently manage herd location.
Spotted: Heat is crucial for many manufacturing processes. However, generating that heat is also emissions-intensive, with industry responsible for 30 per cent of all of the UK’s heating-related greenhouse gas emissions. One solution is the use of renewable sources, like solar, but this is an intermittent energy source and is not always available when it is needed. To solve this problem, British startup Caldera has developed a new type of heat storage system.
Caldera’s system includes a solar array of almost any size. The solar power is stored as heat, using novel storage cells made of an aluminium-volcanic rock composite encased in vacuum insulation. These highly efficient modular cells are rapidly heated to 500 degrees Celsius and can store this energy for hours, ready to deliver heat on demand at temperatures between 80 to 200 degrees Celsius, which is the temperature range needed for many industrial processes.
The cells can deliver heat whenever required, allowing businesses to substitute on-site solar for more expensive, and non-renewable, gas and electricity. As Caldera explained, the system allows industrial players to capitalise on affordable and abundant solar energy, which can be generated on-site or nearby, and stored until it’s ready to be used.
In June of this year, Caldera was awarded £4.3 million (around €4.9 million) from the UK Department for Energy Security & Net Zero to build a full-scale demonstrator of the system.
Heat storage is a focus of a number of recent innovations spotted by Springwise, including using scrap aluminium to transport heat and hydrogen and a storage system that captures waste energy for reuse.
Spotted: Windows have remained functionally the same since their invention; providing natural light and perhaps a level of aesthetic beauty to a home. However, this has meant that while the home has undergone technological smart advancements with heating, storage, electricity, and other things, windows have fallen behind.
Windows account for about 30 per cent of heat loss in a home, and during hot periods, they often let in too much solar heat, which is often compensated for with energy-intensive cooling systems. And even with the right window insulation, it’s rare that lighting is “just right” for the occupant’s comfort when dealing with shifting natural light sources.
This is where Tynt comes in. The concept is simple: windows that can regulate the amount of light that is let in based on what’s available and also the desire of the operator. This is accomplished by using patented Reversible Metal Electrodeposition (RME).
The technology uses a small electric current to influence the properties of a metal film that rests in between the windowpanes – affecting how opaque the window appears and how much energy it absorbs. By either regulating the current up or down, the opacity of the window will range from completely transparent to truly blacked out. With this system the heat regulation of the house is also far more efficient – requiring just 1 volt to function, according to the company.
Tynt is not in the commercial phase just yet, but you can sign up to be alerted when the first product becomes available, which the company predicts will be in 2024.
Windows are a central part of all modern buildings, but if they’re poorly designed, they can rapidly increase the heat losses and greenhouse gas emissions of a property. In the archive, Springwise has also spotted shade screens that provide renewable sources of energy as well as this company that can retrofit entire buildings with net-zero glass to reduce heating costs.
According to the The International Energy Association, “Heat pumps, powered by low-emissions electricity, are the central technology in the global transition to secure and sustainable heating.” Why? As rooftop solar panels, community solar, and utility-scale renewable energy expand, the incredible efficiency of heat pumps will free us from fossil fuels and help propel the way to zero carbon.
Heat pumps have been around for decades in the form of air conditioners and refrigerators, so the technology is mature and already cost competitive. The Inflation Reduction Act will bring tax credits, 30% off the cost of installation, bringing the technology within reach of even more families and property owners.
And best of all, heat pumps provide better comfort, using a more constant flow of heat compared to the on/off blast of a 3000° natural gas furnace. Heat pumps run smoothly, without temperature swings, and they filter and move more air through the house.
Whole house heat pumps
Similar to a furnace or central AC system, whole house heat pumps pump heat throughout your home via ductwork. For homes with existing ducts, this can be an easy change out of a fossil fuel –burning furnace for a heat pump.
The ducted, whole house heat pumps come in constant speed and variable speed. Constant speed heat pumps (also called single– or dual-stage heat pumps) run at only one or two speeds. They either run at full blast or they’re off, nothing. These often feature a lower upfront cost, but higher operational costs. And they usually require some type of backup (electric-resistance or gas) heating system, because they will struggle to work efficiently below 20° or 30°F. You’ll recognize a constant speed heat pump by the fan on the top of the outdoor unit, looking like a classic air conditioner box.
Variable speed heat pumps run at different speeds, modulating up and down to maintain the target temperature. They run a lot, but at lower energy levels and are overall more efficient. They will cost more upfront, but many work well in much colder temperatures. Thus, all cold climate heat pumps run at variable speeds.
Compared to the on/off blast of constant speed heat pumps, variable speed models run more quietly at lower speeds. You’ll see a more vertical looking outdoor unit with a fan on the side rather than the top. Variable speed units can be used with both ductless and ducted heat pump systems.
In 2021, we replaced an ancient gas furnace on one side of a Cleveland, OH, duplex. This whole-house, variable-speed heat pump provides heating and cooling under highly variable weather conditions. Because it’s used for short-term rentals, we keep it at a comfortable 72° all year. This all-electric arrangement on this side of the duplex costs far less to operate than the gas side.
Ductless system with variable speed heat pump. Image courtesy Mitsubishi.
Source: Air Conditioning, Heating, and Refrigeration Institute data and Electrify Now.
Ductless heat pumps
As their name implies, ductless heat pumps don’t use ducts to distribute heat. Instead, they rely on indoor units (aka “heads”) installed in the wall, linking directly to an individual outdoor condenser; similar to a window or wall air-conditioning unit. This means that no conditioned air is escaping through leaky ducts, nor are ducts exposed to sunlight or unconditioned space. So ductless installations are most efficient.
Ductless heat pumps are logical for any space without ductwork. And they offer efficiency, economic, and environmental advantages over a central ducted heating system. All DHPs use variable speed technology. One downside is that you need to install a head on an exterior wall wherever you want heat; or provide backup electric-resistance heaters for rooms that don’t (or can’t) have a head
In our home in Portland, OR, heat pumps have kept our family warm for over a decade, since we removed our gas furnace. We also gained some square footage in our garage, which we have converted to an accessory dwelling unit.
The home came with baseboard electric heat in bedrooms and bathrooms, in addition to the central furnace. We now have two heat pump “heads” in the living room and master bedroom, and we use the backup electric-resistance heat very occasionally in the other rooms. This hybrid approach reduced our capital costs and costs us incredibly little to run. Our energy bills are only 20% of the national average!
How will they propel us to zero?
A heat pump uses refrigerant to capture heat and then moves that heat into (heating) or out of (cooling) your house. In the winter they pump heat from outside (even from cold air) to the inside, and in summer, they reverse. Here in Portland, and other places across the globe, climate change is bringing a greater need for cooling. A heat pump is, essentially, a super-efficient, reversible air-conditioner that you can use year-round.
Heat pumps are therefore key to decarbonization. As they are becoming more widely available, more contractors are becoming familiar with how to size, install, and maintain them. Of the 41% of US homes that use electricity for heating, only a quarter of those (13 million) use efficient heat pumps. But in 2021, heat pump sales surpassed gas furnaces, in the US, for the first time.
Whether it’s ducted or ductless, in Oregon or Ohio, modern ranches or old craftsman duplexes, our family has used the mighty heat pump to stay warm, save money, and do our part to solve the climate crisis. So while heat pumps might not get as much love, they rank up there with solar panels and electric vehicles as crucial technologies that will decarbonize our lives without sacrificing modern comforts. Let’s get heat pumped up and put one of these amazing machines in every home ASAP.
This article springs from an post by Naomi Cole and Joe Wachunas, first published in CleanTechnica. Their “Decarbonize Your Life,” series shares their experience, lessons learned, and recommendations for how to reduce household emissions.
The authors:
Joe Wachunas and Naomi Cole both work professionally to address climate change—Naomi in urban sustainability and energy efficiency and Joe in the electrification of buildings and transportation. A passion for debarbonization, and their commitment to walk the walk, has led them to ductless heat pumps, heat pump water heaters, induction cooking, solar in multiple forms, hang-drying laundry (including cloth diapers), no cars to electric cars and charging without a garage or driveway, a reforestation grant from the US Department of Agriculture, and more. They live in Portland, OR, with two young children.
American roofing firm GAF has completed the first phase of a public-private initiative that seeks to mitigate urban heat in Los Angeles through solar-reflective coating.
The GAF Cool Community Project completed the first phase of their public project in Los Angeles’ Pacoima, covering asphalt roads and public areas in a 10-block radius to see if a reflective coating might reduce the effects of urban heating.
GAF installed thousands of square feet of solar-reflective coating to public areas in Los Angeles
Members of the GAF team and its street coating arm Streetbond worked with NGOs and city officials including the Global Cool Cities Alliance, Climate Resolve, and the Los Angeles Bureau of Street Service to coat over 700,000 square feet (65,032 square metres) of the neighbourhood’s pavement.
The project was initiated to mitigate the heat in heavily paved neighbourhoods, a problem in urban areas sometimes referred to as “heat islands”.
The initiative is called the GAF Cool Community Project
“This is one of the hottest neighborhoods in Los Angeles,” said Streetbond general manager Eliot Wall.
“There’s not a lot of alternative solutions. There are not a lot of shade structures. There are not a lot of trees – things that we also believe are necessary to help combat this – but this was something that without any other structural changes you could do tomorrow.”
The coating was applied to a 10-block radius
Because asphalt needs to be sealed and coated in dark colours to reduce tire marks and glare, it traps heat and holds it at street level.
The team’s solution was to paint over roads, parking lots and recreational areas with a proprietary coating that the company says may reduce the heat effect by 10-12 degrees Fahrenheit (5.5-6.6 degrees Celsius). The coating comes in a variety of different colours, with brighter colours used for recreational areas and dark ones for the roads.
The coating can be applied directly on top of preexisting asphalt. It can be applied by hand or by a paint-spraying machine.
The coating reflects sun and mitigates the heat island effect
Instead of simply lining sections of street with the product, the team wanted to test how the coating could affect the ambient temperature of the neighbourhood as a whole.
Some of the more recreational areas within the project’s scope, such as a basketball court and public park, were coated with colourful paint mocked up in patterns approved by the residents and a mural by local artist Desiree Sanchez was commissioned to be completed with the coating.
Community members were consulted on a series of designs for the public park
Phase one of the project was completed last year and now the team is utilising a variety of measuring systems to monitor the heat in the neighbourhood as the summer approaches. Wall said that the felt effects of the coating are “pretty much instantaneous”.
“The community members themselves are saying it feels cooler,” he said.
Since the application last summer, the team has noted not only a drop of up to three degrees Fahrenheit (1.6 degrees Celsius) but changes in temperature downwind from the coated area.
The team is testing the effects of the coat through monitoring systems
GAF director of building and roof science Jennifer Keegan added that there could added benefits from cooling large urban areas beyond the experience on the street.
Typically, the conversation around cooling technologies is limited to the application of materials on roofs and for cooling inside buildings, but paved public spaces present opportunities for bringing down the heat in the area in general.
“Not only are we helping the environment with that perspective of reducing the urban heat island effect, and if we keep our cities cooler, we’re reducing our carbon footprint,” she said.
Wall and Keegan said that the initiative hopes to expand the procedure to other areas that suffer from the heat island effect.
Residents have already commented on reduced temperatures
Other products that have been introduced to help reduce heat include a “chameleon-like” facade material developed by researchers at the University of Chicago.
Last year, Dezeen contributor Smith Mordak put together a guide for different strategies to reduce urban heating, read it here.
Spotted: Despite all pledges to reduce emissions to reverse the worst effects of climate change, scientists believe that even if we fully implement all 2030 nationally determined contributions, pledges, and net-zero targets, global warming of nearly two degrees Celsius is still expected later this century. Heating, ventilation, and air conditioning (HVAC) operational costs will naturally rise alongside temperatures, and use of those systems further exacerbates environmental damage.
One way to help reduce reliance on traditional HVAC systems is to retrofit existing structures with energy-neutral solutions that reduce indoor heating during the summer while allowing the sun’s rays in during winter. French technology company Immoblade has taken inspiration from the space industry to create low-cost, quick-to-install, custom sunshade blades on windows and roofs.
The blades are available in a range of shapes and sizes, from the barely visible designs of the Immoblade Mini to the wide, closely fitting stripes of the Immoblade Serigraphy. Installed in the same way as regular double glazing, the blades allow light into the building while blocking heat when the sun reaches a certain angle. Similarly, when the sun is below a certain angle during the winter, the blades allow heat to enter the building.
Each solution is custom designed for the location and the structure, with the Immoblade team conducting a full thermal review of the building’s façade and local environment. The design of each set of blades meets the exact heating and cooling requirements of each piece of glass, and performance is monitored throughout the duration of the lifespan of the blades. Maintenance costs are zero as the designs and applications are fixed.
Immoblade was first spotted by Springwise in 2021, and was one of the featured solutions at ChangeNOW 2023.
Glass bricks that collect solar energy and nailable solar shingles are two other recent innovations in solar energy that Springwise has spotted helping to make renewable power more accessible and widespread.
