Assertion Supported
Rivest: Humidity management uses over half of AC electricity on average
“But it turns out that humidity is using on average a little bit more than half of the electricity of our air conditioner.”
Assertion Contradicted
Rivest: Air conditioning is the leading cause of electrical grid blackouts
“I don't know if ice solves the electricity consumption and CO two emissions part of the problem, but it certainly solves a really important problem about air conditioning, which is that air conditioners are the number one cause of blackouts on the electrical g…”
Assertion Contradicted
Rivest: Indoor CO2 levels above 700 PPM impair strategic decision-making
“People were looking at how CO₂ levels were impacting the cognitive function of building occupants, and seeing that strategic decision making and deep thinking were really impeded by Higher levels of CO two. And by higher, I mean like, 700 or 800 PPM. Not reall…”
Insight
Rivest: Productivity gains from clean air outweigh building energy and rent savings
“There were a lot of seminal papers out of Harvard talking about this and making the argument that the more productive you can make your space, it totally pays for itself if you could somehow measure that productivity. It's much it's much more impactful on the …”
Assertion Partly supported
Rivest: Alternative cooling technologies are not close to commercial market deployment
“So between new types of heat pumps, solid state heat pumps low global warming potential, refrigerants, and water evaporative cooling, There are other options up and coming, but certainly not on the market or about to be on the market.”
Insight
Rivest: Heat pump mandates accelerate the retirement of inefficient air conditioners
“What I think is really interesting about all these heat pumps coming online for heating purposes to replace natural gas is that this disrupts the sales cycle of air conditioners as well as a side benefit. So now you have air conditioners, which would last for …”
Insight
Rivest: Efficient Cooling Delivers 2-to-5-Year Paybacks but Buyers Fixate on CapEx
“Because we're used to looking at most, if not all, of these energy efficiency technologies as capital expenditure rather than total cost of ownership, it becomes difficult to incentivize people even though the economics say, yes, of course you should do that. …”
Assertion Supported
Rivest: Air Conditioner Buyers Globally Always Buy the Cheapest Unit
“While there's a range of air conditioning efficiency available on the market, by and large, people buy the very cheapest thing they can buy. In rich countries, in poor countries, they're buying the cheapest thing they can buy.”
Assertion Supported
Rivest: Some Ultra-Efficient Cooling Systems Never Pay Themselves Back
“There are certainly options for much, much more efficient systems that would never pay themselves back.”
Insight
Rivest: Local efficiency mandates drive down global costs for high-efficiency HVAC
“Once companies start making it for one country in a much more efficient standard, the costs get driven down in that, and it's easier for them to distribute globally.”
Prediction Open · timeframe Dec 2050
Rivest: Energy consumption from cooling will at least triple by 2050
“It depends upon how other sectors grow, but we know that cooling will at least triple in energy consumption between now and twenty-fifty.”
Assertion Supported
Rivest: Air conditioning emissions are 60% electricity, 35% refrigerants, 5% embodied
“There are three major components. One is having to do with the manufacturing and transport of those, and sort of the embodied emissions. And that's about five percent of the emissions that we see coming from air conditioners. There's another 35% that comes fro…”
Assertion Partly supported
Rivest: Commercial ACs overcool air to 50°F before reheating to 70°F
“So what air conditioners do today in a nice commercial building in the U.S. Is they cool air from 90 degrees down to 50 degrees Fahrenheit to get it really, really dry, and then they heat it back up to 70 degrees to make it a comfortable temperature.”
Assertion Partly supported
Rivest: Natural gas and fuel oil remain cheaper than heat pumps across most of the US
“It's much cheaper today in, in most parts of the U.S. To use natural gas or fuel oil to create the heat that you need if what you're looking for is heating.”
Assertion Supported
Rivest: SEER air conditioning ratings completely ignore humidity management efficiency
“Also, the SEER rating does not comprehend the humidity management. So whether you're managing humidity very efficiently or not efficiently at all doesn't impact the SEER rating.”
Assertion Supported
Rivest: Air conditioning causes roughly 4% of global emissions, twice aviation
“So I mentioned at the beginning that we're around four percent of greenhouse gas emissions for air conditioners globally, and that's a big number. I think most of the people who are listening to this podcast will be well calibrated to that number, but It's clo…”
