Read all of the “Two-flat owner journal” entries
This journal entry is all about the several hours of time I spent researching which water heaters to buy for my two-flat. While my architect works on drawing the plans, I am doing a lot of research to answer questions for him, so he knows what appliances are going to be hooked up to the house’s mechanical systems.
I started researching water heaters on a cold Saturday in January so I could fill out the “appliance schedule” for the project. My first journal entry was about my new distaste for Peoples Gas. Since then, my view has evolved and we (my architect and I) are designing an all-electric house.
SCROLL DOWN FOR THE RESEARCH – Read on while I discuss my thoughts about electricity and natural gas as a power source for homes.
Discussion
Let me step back a moment. I also have a “distaste” (a weird word to use when talking about something that would literally kill you if you drank it) for fossil fuels, too. When I approached this research task I thought that an electric tankless water heater had some kind of inherent efficiency over an electric or natural gas-powered tank type.
But it doesn’t, and that’s partly dependent on how much water a household uses. Tankless water heaters are sometimes marketed as providing “unlimited” hot water, which scared me. Since I don’t go to an office anymore (because of COVID-19 and because I quit my office-attached job), I take a shower every other day. And they’re long. Just imagine that your shower never ran out of hot water. I might not get out. So that’s a personal critique of the type of water heater.
(Another con of tankless water heaters: When the electric is off, water cannot be heated; with a tank water heater, there is always residual hot water in the tank, which can still flow. Additionally, electric tankless water heaters have special electrical box requirements because they draw so much electricity.)
Let’s talk about the fuel. Natural gas is cheap right now – to purchase. But it has awful costs elsewhere, namely its contribution to pollution and carbon dioxide emissions when burnt. Burning it in the home also releases additional gases, which is why I think you should run your range hood vent/exhaust when you cook food on the stovetop.
Gas stoves emit a host of dangerous pollutants, including particulate matter, formaldehyde, carbon monoxide, and nitrogen dioxide.
Mother Jones, “How the Fossil Fuel Industry Convinced Americans to Love Gas Stoves”, by Rebecca Leber, FEBRUARY 11, 2021
Going electric in the kitchen is pretty easy, I think. I didn’t do much research and I picked out all Energy Star-certified appliances. For cooking I chose a range with an induction cooktop and an electric convection oven (which means there’s a fan inside to blow the heat around for even cooking). Induction cooktops, while being a really efficient user of energy, have cooking benefits: Water reaches a boil faster, the surface is easy to clean, and there are fewer burns because the surface doesn’t get hot.
Creating an all-electric house is pretty easy, actually, until you get to the heating and cooling part, and knowing how to heat a house with electricity in the very cold climate of northern Illinois requires even more research.
Water heaters are actually easy to figure out (after 5 hours of research) because, in the end, all you do is plug them in to a 240 volt receptacle and connect to the already-existing water pipes.
I am still in the middle of researching electric heating and cooling and I’ve opened a conversation with two HVAC contractors (one that sells Carrier and one that sells Mitsubishi).
Water heater research
I originally tweeted all of this on January 16, 2021, because I like using Twitter as a sounding board.
I have researched five types of water heaters because I want to fully understand the purchase price and energy price of each.
- Natural gas, tank
- Natural gas, tankless
- Electric, tank
- Electric, tank (hybrid w/heat pump)
- Electric, tankless
Based on my research of manufacturers’ reported “Energy Guide” stickers (the yellow stickers required by federal law) for these five types, the Electric, tank (hybrid w/heat pump) (option 4) is far and away the most efficient water heater.
The Electric, tank (hybrid w/heat pump) has an annual operating cost of $104. What is this thing? It takes the standard tank, uses electric heating elements (think of the wires inside your bread toaster), and extracts heat from the air in your house with the heat pump. That’s pretty amazing: There is free heat to be extracted from the air.
The Electric, tank (hybrid w/heat pump) has less than half the operating cost of the next lowest type: Natural gas, tankless.
Note that the electrical prices in the yellow “Energy Guide” sticker is 12 cents per kWh, and ComEd just charged me ~7 cents per kWh, so the annual operating costs of electric are less than the stickers say.
Next, as part of the “total cost of ownership” (well, minus maintenance) I added in the purchase price. The Electric, tank (hybrid w/heat pump) costs $1,400. That’s 1.5-4x more expensive than the other types of water heaters!
However, I’ve since found that Rheem/Richmond makes a couple cheaper models that don’t have high-tech features, so the purchase price is anywhere from $1,000 (if you can find that model) to $1,175.
I calculated the “5 year cost of ownership” price for water heaters of each type because it makes sense to distribute the purchase price over a period of its lifetime. I could have easily made this a 10-year amortization since water heaters come with 6 to 12-year warranties. I interpret the length of the warranty as the manufacturer’s assessment as to how durable they’ve created the machine.
How they compare
Of the five types, I compared 11 machines (view the comparison chart).
The cheapest water heaters over five years are:
- Electric tankless
$1,479 (caveats in that annual energy cost was extrapolated because a direct Energy Guide sticker wasn’t found) - Electric, tank (hybrid w/heat pump)
$1,695 (does not include federal tax credit) - Natural gas, tank
$1,999
Remember, though, that the Energy Guide stickers for the electric water heaters use a 41.7 percent higher energy cost than ComEd currently charges, and ComEd offers hourly pricing so the price can be much, much lower per kWh and the prices for the electric water heaters are EVEN LOWER. (Thank you for pointing this out, Troy.)
Guess what…the price of the Electric, tank (hybrid w/heat pump) can come down even more because of (1) a ComEd rebate, and (2) federal tax credit worth 10 percent of the purchase price + installation, up to $300.
Bonus: By getting electric you are part of the carbon-free future.
Further discussion
Now that I’ve convinced you that an Electric, tank (hybrid w/heat pump) water heater is the cheapest option, here are a couple of other things that came up in the Twitter conversations.
- Including utilities (i.e. electricity cost) in the rent for the rental apartment in my two-flat benefits both me and the tenant. The tenant has a fixed and predictable energy cost and fewer bills to pay, while I am able to charge a bit more than I predict the cost will be in order to pay back the higher upfront costs of the water heater and the Energy Star-certified appliances (as well as the heating and cooling system).
- The calculations might be different if I looked into having individual tankless water heaters at the point of demand, or using them as “boosters”. Tankless water heaters come in a variety of capacities and energy outputs (measured by how much energy it takes to increase the temperature from how cold the water is when it enters the house or heater to the desired temperature). One could be added to the kitchen, the bathroom, and next to the laundry, and sized for the differing demands of each location.
- A complex system could be built that is programmed to buy energy from ComEd when the hourly cost is the lowest and use the power from the battery when the hourly cost is highest.
- A couple people asked about geothermal. I looked into it and I wrote it off quickly: A drilling rig needs to access the yard to drill multiple horizontal wells. The garage blocks that from happening. However, an apartment building renovation in Rogers Park designed by PMP Architects is converting its heating system to use geothermal energy.