Everywhere I go the question I hear is how do we electrify our buildings? With the cost of renewable energy dropping and more people leading the charge towards decarbonizing buildings, design and construction is desperate for solutions. One of the biggest challenges in commercial buildings is the mental shift in how we heat buildings and stop using natural gas as a crutch. Heat pumps are the heart of this shift.
There have been several leading discussions on domestic hot water and residential heat pumps, though few are talking about the commercial space. To really accelerate this market, it will take rethinking how designers, regulators and product vendors can work together. The positive side is there are a lot of energy savings opportunity and designed right can reduce operating costs today and over time.
Drivers Towards Heat Pumps
At the design and construction level, champions of net zero energy and health buildings are clamoring for electrification. To really get to ZNE, it requires electrifying everything. And to really avoid health problems for everyone, eliminating on-site combustion makes a lot of sense. Leading research groups like the Living Futures Institute and New Buildings Institute are promoting the connection between low energy buildings and a human health and well being. Builders like DPR Construction are manifesting these goals in real buildings, both for their own employees and the clients they work for and leading by example of how it can be done.
At a higher level, leading cities like Boulder Colorado and energy aggregators in California like Silicon Valley Clean Energy and Sonoma Clean Power are trying to get out in-front on electrification. Energy municipalities like Sacramento Municipal Utility District (SMUD) just launched an the Advanced All-Electric Smart Home, basically helping home owners achieve what I would love to do in my own house!
On the technology side, heat pumps have been around for a while, though they new to the market in many ways in the US. In Norway, one of the world’s largest heat pump plant pulls heat out of an icy river and is still able to provide well over 85% of the heat for a community of 65,000 people. An article from 2015 shares the insights to the danish community project. To quote one of the developers “We are slowly waking up the idea that we don’t need to burn new fuel to heat things up, we can harness heat in the local environment,” says Mr. Pearson of Norway.
“The potential is clearly huge. For example, the company calculates that the Thames river could generate 1.25GW of capacity, enough to heat 500,000 homes.”
In new and existing buildings often, the steps to electrifying a buildings heating is not a like-for-like replacement with natural gas. The engineering skills in design and construction tend to favor the incumbent solutions and change is more a perceived challenge then we might think.
As a building engineer, this is what I love. I live for the details of making buildings work and helping to unpack the ‘magic’ of how several buildings are already going up, all electric, and finding ways to make them cost neutral and cheaper to operate now and into the future.
Myths to Debunk
Heating with heat pumps is a bleeding edge technology.
Heat pumps have been around for a long time. In fact, compressors which power heat pumps also power chillers and DX systems. Even with a desire for more products in the US and CA markets, we still have several very amazing heat pumps ready to go today with great track records.
The price of electricity is so much more expensive than natural gas, even with a heat pump.
The days of this argument are numbered. The two biggest drivers are higher efficiency heat pumps, able to simultaneous heat and cool, combined with changing energy costs and rate schedules. In large commercial buildings in CA, nearly half the cost of electricity can go towards the peak demand costs. A true accounting of the actual cost of the kWh to heat vs the cost of natural gas is nearly break-even and I predict is already cost positive today, we just have not proven it.
Heat pump first costs are very expensive.
Like all great engineering answers, it depends. Heat pumps do look expensive compared with natural gas boilers. Though a heat pump vs an air cooled chiller might not look so different. And if buildings can combine their primary heating and cooling device into one heating and cooling heat pump chiller, costs can be further saved. An integrated lens is the only true way to assess the costs.
Top Questions When Electrify Heating
For people who are new to heat pumps or considering them in a commercial buildings, here are my top recommended questions to ask when electrifying your heating.
1. How is space heating currently done today? With a centralized boiler or furnaces?
In existing buildings, many are already piped with gas for heating. In centralized boilers, the challenge will be one of replacing the boiler with a heat pump and seeing if the installed infrastructure of heating coils are sufficient. Luckily, most HVAC systems are oversized, so even with cooler hot water, this strategy can work quite effectively.
2. What are the impacts to building electrical infrastructure and service?
In residential homes, this can be one of the biggest challenges. In commercial buildings, often the heat pump will not be larger than the air conditioning and may not impact service size. It is always something to weigh and do your homework on.
3. What temperature hot water is used to heat the building? Is this temperature actually needed?
Several hot water buildings with boilers run hot, pumping 180 deg F water. Often, heat pumps tend to run cooler, 100 to 140 deg F. Heating, especially in CA can use this lower temperature and still function. Existing buildings should stress test what temperature they really need. And in radiant buildings, a floor can use 80 to 90 deg F water even.
4. What types of heat pumps exist and would work with a building?
- Air to Air – these are typically in homes and small buildings. Not the most efficient though all electric.
- Air to Water – these are amazing devices and great solutions for many buildings. There is a wide variety of vendors, from Multistack, Aermec, and Smardt to name a few big ones.
- Water to Water – the same as a chiller, these tend to be bigger machines. Great in finding ways to electrify large buildings.
- Geoexchange – packaged products come ready to go and be marketed as this.
- Sewer Mining – Sharc Energy has one of the most amazing heat pump systems and multi-family housing should be using these whenever possible.
5. What are the regulatory hurdles today for heat pumps?
In California, one of the biggest challenges is how Title 24 compares new buildings to ones with natural gas. Electric heating, heat pumps, are weighted differently and overall, make it harder to show compliance with the current energy code.
How Do We Grow this Future?
The biggest need I see is for more widely available heat pumps for space heating and hot water. In commercial buildings, air to water heat pumps are going to be key. Large heat pumps are being used around the world, though in California, we need more representation and heat pump promotion. Key technical pieces needed are more information on heat pump energy performance. As an energy modeler, I need access to part-load performance data and ability to take credit for these when getting a permit. As a engineer and design consultant, I need strong case studies and experts to be able to bring on and educate me on the pros and cons. Solutions to manage cold climates and design strategies for heating when temperatures drop below freezing.
Built Projects with Heat Pumps
Net Zero Energy Buildings with Water to Water Heat Pumps (Multistack)
Net Zero Energy Buildings with Air to Water Heat Pumps (Aermec)