Messages from the Edge, July 2024
Where we are
To review, we will provide you with a monthly contemplation on ‘Getting to Zero’ for the next eight months. Science tells us we have 25 years to reduce our emissions to Zero. We are looking at a carbon reduction diet, which begins by looking at the big picture. We wish to turn the right side to Zero by 2050 or:
(Lighting + Heating + Cooling + cooking + driving +refrigeration + embodied energy + heating water + utilities + gardening + vampire power) – (Clean Energy we Produce or Offset) = (Everything we Use)
This month, Alan has agreed to take on Heating and Cooling. This Message will explain that modern heating relies on moving heat rather than combustion.
I have elected to delve into your refrigerator as a prime example of a clever device that moves heat instead of creating it through burning. Yes, you probably already own a heat pump! What we glean through our inquiry will apply to our upcoming discussion on replacing your gas-fired water heater or resistive electric water heater, which you can do with a heat pump alternative.
Heating and Cooling: Contributed by Alan Ness
Recommendation: After you have “insulated tight and ventilated right,” consider opting out of using an oil or gas furnace: Go for an electric Heat Pump system. Remember that Heat Pumps provide air-conditioning as well as heat. As David has mentioned, this can be a long-term decision (waiting for your exisitng system to break down) but one you want to be prepared for.
A Heat Pump is an ingenious machine for taking heat out of the air in the winter, and taking “coolth” out of the air in the summer, delivering both into your home. How cold can it get and still find heat in the air: -19 degrees F below zero, although the efficiency break point is about 15 degrees F. See “My Personal; Story” for a reality check.
A note on efficiency: Gas furnaces get up to 95% efficiency. There is alway some heat lost when you burn fuel. Heat pumps get 300% to 400% efficiency – the energy to circulate the fluid of the system is quite a bit less than the energy derived from the ingenious heat transfer system itself.
There are two styles of Heat Pump installation:
- Ductless mini-split
- Ductwork using a blower
#1. The ductless mini-split has the main unit outside your house. Then tubes are connected from the unit, attached to the side of your house and connected to small ‘heads” inside the rooms needing cooling and heating. These ‘heads’ are the size of small window air conditioners set high up on your walls. This is great for houses with no existing ducting, such as houses with electric wall-unit heaters. There is a thermostat for each room
#2. Ductwork using a blower. This is what I used. The same unit is outside of my house, and feeds into a blower in my basement where my old furnace used to be. The blower then blows air over the warmth or coolth, into the ducts and feeds all the rooms of my house as before. There is a central thermostat just like my old one.
A Story: My friend told me that his Hot Water Heater broke down recently and they got it replaced. I asked him if they got one with a small heat pump on top, and he said “Alan, this was an emergency situation.” Clearly they had not contemplated and thought ahead about clean energy alternatives.
My Personal Story:
2020. We wanted to go further in reducing carbon output from our house. We ripped out a perfectly fine gas furnace (about 14 years old) so that we stopped burning so much fossil fuel in our own home.* In addition, I had seen very hot days in Seattle go from one day a year to one month a year! Going to a heat pump would give us air-conditioning as well as heating. From the perspective of the 2021 Heat Dome it has already been worth it. A key fact: Seattle electricity is 97% renewable sourced, mainly hydropower. It is important to know the source of your electricity and fight for power companies to convert to 100% renewables.
*But the Sunk Cost Fallacy: See below: Why use the elevator now? You’ve already put a lot of effort going up the stairs. This is the logic that says, “don’t rip out your existing furnace – you paid for it and it still works.” But sometimes it is better to move on. I am never getting the actual money back for my furnace, ever. It is a sunk cost.
Finally, let’s talk about comfort. You buy a heating system so you can be warm and comfortable in the winter. I don’t know about you, but even with my gas furnace, I used plug-in electric heaters to supplement the heat, especially in the room that I was using.. I still do this (occasionally) with my heat pump. The other strategy is to put a heating wire into the beginning of the ductwork and have air blow over it when it is really cold. Bottom line: you need to do what is needed to be comfortable.
However, I think that any heating company that tells you that you need a gas furnace as “backup” is egregious. That is just a ripoff. But I have heard of this more than once. .
Refrigeration
On a very local scale, a refrigerator is the center of the universe. On the inside is food essential to life, and on the outside of the door is a summary of the life events of the household. ~ Robert Fulghum
A refrigerator transfers heat from its inside to its external environment, cooling its interior to a temperature below room temperature. It uses a heat pump that compresses and depressurizes a refrigerant. A refrigerant is a substance that changes from a liquid to a gas and back again. When the refrigerant evaporates, it absorbs heat from the food items inside the fridge. When it condenses, it releases heat to the surroundings outside the fridge.
Last year, I made a refrigerator in my basement. And I needed to because I needed to figure how – you know there is no such thing as ‘cold.’ There is only less heat. ~ Alton Brown
A Brief History of Food Refrigeration
Refrigerators are a relatively new invention. However, attempts to preserve food have been going on since ancient times. Humans began freezing water into ice for food preservation in 1,000 B.C. in China. Other early societies, including the Greeks, Romans, and Hebrews, used snow to cool food. Until the last century, refrigeration involved ice blocks.
How Refrigerators work
Alan has covered the theory of operation above, but the principle is packaged into the refrigerator you probably have in your kitchen.
If you wish to dive deeper, here is an explanation of how refrigerators work. Here is how freezers work.
Energy Star Certification
Like the Miles-per-gallon or Miles-per-charge for automobiles, appliances have followed suit with an EnergyStar sticker. This sticker allows you to compare the tested performance of commercially available appliances. Operating costs are an essential data point. The operating cost only counts the power consumed to run the appliance. The reliability and maintenance costs must be determined elsewhere, such as through a resource like the Web or Consumer Reports.
This sticker is also an example of individual choice affecting a system problem. EnergyStar requires a known performance, which means buying appliances that display the EnergyStar (such as the laptop I am writing this on) will drastically reduce the collective greenhouse gas emissions.
To be able to display the EnergyStar sticker, a product must prove:
- ENERGY STAR-qualified products, homes, buildings, and services are more energy efficient than conventional products, homes, buildings, and services (between 10 and 90%) and help reduce greenhouse gas emissions.
- ENERGY STAR identifies cost-effective solutions, providing payback for any higher initial cost within several years.
- There are no tradeoffs in performance or quality.
- ENERGY STAR builds upon the federal government’s technical resources and objectivity.
Energy Star in other countries
Currently, six countries, plus those of the European Union and the European Free Trade Association, have agreements with the U.S. EPA on ENERGY STAR. The six countries are Australia, Canada, Japan, New Zealand, Switzerland, and Taiwan.
The ENERGY STAR program, which promotes energy efficiency, is implemented in several countries. Here are the ones currently administering the program:
- Canada: Natural Resources Canada (NRCan) oversees ENERGY STAR for products, homes, commercial buildings, and industrial plants. They have unique requirements for ENERGY STAR-certified homes and support using the ENERGY STAR Portfolio Manager® for assessing energy performance1.
- Japan: P2 company implements ENERGY STAR on behalf of the Ministry of Economy, Trade, and Industry for office equipment like computers, displays, imaging equipment, and computer servers1.
- Switzerland: The Swiss Federal Office of Energy (SFOE) implements ENERGY STAR for computers and imaging equipment, with eligible models certified through the U.S. and available in the U.S. and Canada1.
- Taiwan: Although not mentioned in the previous sources, Taiwan also recognizes ENERGY STAR and collaborates with the US EPA on energy efficiency initiatives2.
In addition to these countries, Australia, New Zealand, and the European Union (E.U.) have also made agreements with the US EPA regarding ENERGY STAR2.
Signs of imminent failure
The expected life expectancy of Refrigerators is 10-18 years. At about a decade, looking out for signs of imminent Bardo activity is advisable. COVID-19 severely constrained the appliance supply chain, but these are generally readily available should yours need replacement. Regarding efficiency and reduced indirect carbon emissions, we recommend shopping by Energy Star rating, consumer reports, and features desired. Refrigerators are not considered phantom loads. They are a part of your home’s baseload demand: choose them wisely!
Know the signs that it’s time for a refrigerator replacement.
- The rear exterior surface of your fridge is generating an excessive amount of heat.
- Food spoils prematurely even when you correctly set the temperature adjustment control to a food-safe setting of 40 degrees Fahrenheit or less.
- You frequently see condensation inside the fridge, but the fridge door gaskets are in good condition.
- The fridge buzzes loudly even after unplugging and plugging it back in.
- Your fridge is entirely silent when it’s plugged in (not the expected gentle hum), but there’s no evidence on the electrical panel to suggest that the circuit breaker for the fridge flipped.
- You frequently notice that a thick layer of frost covers the frozen foods you retrieve from the freezer.
- Your utility bills are mysteriously shooting up despite making no changes in your appliance usage. If this is the case, an energy-usage monitor plugged in between the fridge and the fridge outlet will indicate that the refrigerator is drawing more wattage than it has in the past. It might be time for a more energy-efficient model.
Anecdotal Refrigeration Tales
Evaporative Cooling Beer in Death Valley
In college, my Ecology Class took a Spring Break trip to Death Valley. Even in the spring, Death Valley is quite hot. I experimented with using evaporative cooling, a towel sewn with compartments filled with beer cans, and tied to my front bumper. Evaporative cooling, as demonstrated by why we sweat, worked very well.
Ice Chutes and Galvanized Ice Tray
If your home was built before 1930, you can probably find remnants of ice chutes and ice boxes used for refrigeration before modern systems. The ice man would ride up, park his horse, grab his ice tongs, drag a block of ice to the chute, and drop it in. These were the good old days?
When the power goes down
In 2010, a wildfire predicted by climate science destroyed our Colorado foothills home, and the surviving houses were evacuated. The utility turned off power to the burn area to protect the firefighters and cleanup workers. This power loss meant the unburnt surviving homes had refrigerators filled with spoiled food. There was considerable cleanup of spoiled food and replacement of refrigeration. Due to lawsuits surrounding the blame for an urban wildfire that destroyed 1100 homes this past winter, the utility shut off power for three to four days during a not-so-severe wind event. Food spoilage again occurred, affecting the 50,000 homes affected by the ‘safety’ shutdown. The blackout also affected businesses. When power was restored, they trashed spoiled food, restocked empty refrigerators, and left bare the markets’ perishable food sections. These examples form a cautionary tale that you all might consider.
Homework – Circularity
What happens to the resulting heat if we move heat to create cold? Consider how you might use that ‘wasted’ heat for your homework. If air source heat pumps heat water and cool the air and refrigerators cool food and create heat, shouldn’t they work together?