Baseboard: Electricheater with no fan located wher ethe wall meets the floor. Cold air is warmed and rises up the walls to the ceiling. Most houses with these will have ceiling fans to blow the warm air down in the center of the room where it cools and spreads back to the heaters. Not very efficient and you lose the ability to place a couch or bed next to that wall.

A furnace is like your oven. It burns a fuel, could be natural gas, propane, or fuel oil. A fan forces the warm air into the room, or into ducts that lead to vents in each room (this would also be central heating).

Central heatimg... the heater is in one location, normally the canter of the building with ducts leading to rooms and hallways. Cooling that works the same way is central cooling.

A window unit would be those AC units mounted in a wi down, and sometimes a hole in the wall, though there are dedicated wall units too, some of those also have a heater. Often used to just cool a room, or a small house at most.

Radiators are old school and suck. There is a large radiator, like what's in a car or AIO in a P , that has your hot pumped through it. The heat from the hot water going through those pipes warms the area. Larger buildings will have a boiler dedicated to heating water for this, and this is usually better. It can be heated to a higher temp si ce there's no danger of your turning on your hot water faucet and scalding yourself, and since it's in a sealed loop there won't be any loss of heat because you're taking a shower like Wil happen with one that uses shared hot water.... those really suck. Ok in summer or extremely mild winters, but are terrible when it's on the 30s or below. Bad in the 40s even.

A heat pump is based on a Peltier I believe. Or at least works in a similar way. It takes the heat from.k e location and sends it to another. This can be used to her or cool your home. Usually not used in extremely cold places and where it does get cold it wil.often have another heater as a back up if it can't maintain the temperature.

Wow thank you! Are furnaces & central heat different?

They are different things. A furnace is just the source of heat. It could je a single wall mounted unit or it could be the heat source for a central system. And could be a gas furnace or an electric furnace even. The furnace is the heat source used in multiple types of heating systems.

> forced air

It has as a fan and blows heat.

If you have a fireplace or radiator, it just gets hot and doesn't actually blow it.

> a furnace

Burns something for heat. This can be natural gas which is piped to the the house, or:

> liquid propane vs heating oil

Propane is an explosive gas. It burns up in a couple seconds.

Oil is not explosive, it burns very slowly and releases more heat, but often produces more smoke.

Oil is safer and easier to haul. Theoretically it might freeze and become buttery in very cold conditions.

> "central"

One unit for multiple rooms. You have ducts (big pipes) that can blow hot air through multiple rooms.

> geothermal

If you place a big container of water in the freezer, it might take days to freeze. The outside can freeze while the inside is warm.

If you have a big mountain, it heats up slightly in the day, and cools down slowly at night. But because it's so different the temperature stays pretty constant. Sometimes it's even constant throughout the year.

If you did a hole that's deep enough, it just keeps getting warmer underground. There's so much dirt that it weighs a lot and won't freeze easily. Eventually if you go super deep your get hot lava.

With geothermal you dig a hole or trench that's deep and run a water pipe through it. When you put cold water in the pipe, the heat deep in the ground will heat it up so you get warm/hot water on the other end.

> boilers

A fire or electric heat that boils water. These are used for big buildings.

Instead of running ducts with hot air.

They run pipes with steam or boiling water.

> Radiator

The hot water from a boiler flows through it and makes it hot. There's no fan, and sometimes they don't even use electricity.

https://upload.wikimedia.org/wikipedia/commons/0/02/Household_radiator.jpg

It just gets hot, and as a result sometimes one side of the room is hot and the other is cold.

If a fan is added it can be a hydronic system and it evens out the temperature better. With a hydronic system, you can also pump cold water and use it as an A/C.

> heat pump

An air conditioner has two ends. One blows hot air, one blows cold air.

Normally you want the cold air to blow inside, and the hot air to blow outside.

It turns out if you run an air conditioner backwards, it will blow cold air outside, and hot air inside. This makes it surprisingly effective as a heater.

An A/C actually produces more heat than cold.

Let's say it's 10 degrees outside. If you cool the outside part of the A/C to zero degrees.

The 10 degrees air actually warms it up from zero to ten degrees.

Because of this, a heat pump can actually grab little bits of heat from outside and it's one of the most energy efficient ways to heat a house.

> mini splits

An A/C has a hot side, and a cold side.

With a mini split you leave the hot side outside, and the cold side inside.

These are connected with pipes instead of ducts.

Pipes end up being more efficient than ducts.

With a central system you have one system for the whole house, or 2-3 zones in a house.

With a mini-split you can have one system for each room.

These systems can each have their own outdoor box, or they can share a big outdoor box.

Mini-splits are especially easy to run backwards and use as a heat pump.

By heating/cooling just the rooms you need you can save a lot of power vs heating/cooling your whole house.

> baseboard

A heater on the bottom of a wall: https://images.thdstatic.com/productImages/a8027bb7-12b0-4200-93c8-260d3ff7c00f/svn/whites-cadet-baseboard-heaters-ebhn1500w-4f_600.jpg

> window units

Mounted in a window. Typically these are air conditioners, but some can do heat as well.

Since they're in a window they can blow the hot air outside the window, and the cold air inside.

They don't need any ducts, pipes, etc.

Did you write all that out? Thank you so much. I am saving this for when I buy a house.

Heat pumps don't use peltier elements. They compress and expand a gas.

I had it backwards then. A peltier is a type of heat pump, not the other way around.

Yes, I had written it all and tried to keep it simple.

It's also noteworthy that fire was used for heat for many thousands of years.

Boiling water with fire was used for heat before electricity even existed. So boilers could work in apartment buildings in places like New York or Chicago with fanless radiators.

When electricity came out, adding a fan made heaters more comfortable at it evens out the temperature in a room.

Heat pumps are a fairly recent idea, and are by far the most energy efficient way to heat a house along with geothermal. Both these technologies are able to basically absorb heat from outside.

Even if it's zero degrees outside, there's still some heat because it's not -40 or colder.

Oil and propane are used for rural houses and have to be delivered by truck. More urban houses can have natural gas that's piped.

Hydrogen is a clean gas that could theoretically be used instead of natural gas, but probably won't be.

Burning things was traditionally much cheaper than electricity. So for big houses in areas with cold winters it made sense before.

Today if you burn natural gas, hydrogen, propane, oil, or wood at a power plant to make electricity. If this electricity powers a heat pump it will produce more heat than burning it at home.

As a result heat pumps work better than hydrogen at your home.

Heat pumps have trouble in super cold weather though, but they're improving as a new technology.

Early heat pumps struggled below 40 degrees Fahrenheit (roughly 5C).

Then they got them to work down to 32 degrees Fahrenheit (zero C).

Now some can work below -10 Fahrenheit (-23C).

Please read this entire message

Your submission has been removed for the following reason(s):

• Rule #2 - Questions must seek objective explanations

• Whole topic overviews are not allowed on ELI5. This subreddit is meant for explanations of specific concepts, not general introductions to broad topics (Rule 2).

If you would like this removal reviewed, please read the detailed rules first. If you believe this submission was removed erroneously, please use this form and we will review your submission.