Building Heating & Cooling
Building Heating & Cooling
Keeping Warm & Cool
We’ll be digging into heating & cooling in this issue.
Source: Breakthrough Energy
7% of world GHG emissions come from heating and cooling our buildings.
Before we dig into the specifics, we want to start by highlighting the importance of heating and cooling to overall building energy efficiency.
Building emissions can be classified in two ways:
Embodied carbon emissions
This relates to the materials we use to make buildings: manufactured steel, concrete, and even plastic. So, a large part of building emissions are actually dependent on the progress we make to net-zero within the manufacturing sector. We’ve covered the emissions from manufacturing at length in our previous posts.
Operational carbon emissions
Operational carbon emissions relate to daily use. The operational carbon emissions from our use of buildings account for about 10% of total GHG emissions. At 7% of world GHG emissions, heating & cooling is therefore responsible for a whopping 70% of the operational emissions that come from buildings.
The remaining 3% of global GHG emissions from buildings’ operational carbon emissions can be attributed to uses such as lighting and powering various electronics -- we’ll discuss these in other posts.
Basics of Heating & Cooling
Building temperatures are managed through HVAC (Heating, Ventilation, and Air Conditioning) systems. Residential and commercial HVAC systems are similar -- the main difference is size.
HVAC systems adjust building temperature by circulating air through ductwork.
Air heating and cooling is done using variations of these three HVAC systems:
Furnaces that generate heat using electrical energy or burning fuel sources such as gas, propane, and oil.
Air Conditioners that use refrigerants to absorb the heat from within a building and move it to an outdoor location.
Heat Pumps that work to transfer both hot and cold air from one place to another.
Path to Net-Zero → Clean Electricity Sources & Heat Pumps
In other industries we’ve covered, innovation was still required to bring down the green premium. That’s not the case here. The path to eliminating operational carbon emissions in buildings is clear.
With heat pumps, we can heat and cool our buildings today with clean electricity.
And heat pumps are quickly proving themselves to be cheaper.
Source: Breakthrough Energy
Heat pumps come in two main types:
Air sourced heat pumps that transfer heat between bodies of air
Ground sourced heat pumps that transfer heat between the air and the ground.
The diagram below shows the process, and key components heat pumps use to heat a building. Starting from the right, heat pumps use a refrigerant to absorb heat from the evaporator located outside. The gas resulting from the evaporator is then pressurized, increasing its temperature. Finally, the gas gets moved and released indoors through the condenser and expansion valve to heat the building. Heat pumps are reversible, which means we can also cool the building by reversing the direction of refrigerant flow.
Source: Canada Energy Regulator
Here’s the catch we need to plan for -- heat pumps require electricity because of their compressors (moving heat from one location to another). To be perfect, we need infrastructure to generate this electricity cleanly.
On the other hand, heat pumps are still WAY more efficient than other types of heating that use electricity. For example, heat pumps can use 50% less energy than baseboard heaters because they only need to move heat, while baseboard heaters also need to convert the electricity into heat.
Heat pumps are generally the most cost-effective solution today, but can be less efficient in cold places like Canada where there is less heat to pull from outdoors. Luckily, we’re starting to see increasingly efficient cold-climate heat pumps emerge.
According to a tracking report produced by the International Energy Agency, heat pumps were servicing 7% of the global heating demand as of 2020, but can easily satisfy 90% of global demand.
The image below highlights how impactful heat pumps could be all over the world.
Innovators
At this point, here’s what’s left to do:
Increase heat pump adoption
Increase the availability of clean electricity
Reduce electricity demand in our buildings
(1) Increase heat pump adoption
The most straightforward way to do this is through policy. However, implementing heat pump mandates for new and existing construction will likely take time. Policies that would increase adoption include subsidizing the upfront installation costs of heat pump systems, taxing or increasing the costs associated with fossil-fuel-based heating and cooling, and running awareness campaigns to promote heat pump adoption.
Governments will need to be primary incentive drivers, but the private sector can certainly play their part too. The following companies offer solutions that save dollars for homeowners and facilitate the residential sector’s adoption of heat pumps:
Sealed: https://sealed.com/
Bloc Power: https://www.blocpower.io/
Dandelion energy: https://dandelionenergy.com/
(2) Increase the availability of clean electricity
If we’re going to decarbonize the operations of our buildings, we need affordable sources of clean electricity. We’ll dig deeper into the sources of clean electricity in another post -- for now, we’ll focus on district energy systems, which directly address the building decarbonization problem.
District energy systems are similar to water systems in developed countries. Instead of each building having its own water well, multiple buildings are hooked up to a central system. Heated or chilled water is then distributed through pipes to buildings to heat and cool them.
The economic argument is that by using district energy, we can spread costs and justify investments in larger renewable energy infrastructure. Many district energy systems will rely on sources of energy like biomass, sewage, and lake water which are not economically viable on a small scale.
Source: CBC News District Energy
A few of these are starting to crop up in North America. Check out the Zibi Community Utility. Being developed by Dream Unlimited, Zibi is a 34-acre waterfront community in Gatineau, Quebec. It currency services 100% of the heating needs for three residential buildings and three office buildings (615,000 square feet) without fossil fuels. On completion, this system will serve nearly 4 million square feet of residential and commercial property.
(3) Reduce electricity demand in our buildings
Reducing electricity demand in our buildings isn’t a net-zero solution by itself. The goal here is to reduce the availability requirements for clean electricity. As the requirements decrease, we should see more clean electricity projects emerge due to the lower cost and requirements.
These companies are offering solutions, including new applications of artificial intelligence, to automate and optimize energy consumption in buildings:
BrainboxAI: https://brainboxai.com/en
Parity GO: https://www.paritygo.com/
75F: https://www.75f.io/
Summing it up -- Contrary to our findings on manufacturing which indicated a strong need for inventors, it seems the heating & cooling industry is desperate for implementers!