Furnace Frenzy!

Have you ever heard of a rocket mass heater? Would love to see a video about those. A lot of off-grid folks swear by them but I assume there are major drawbacks or else they’d be more common.

Benjamin Maslow (BEM684)

what i did for CO detection was replace all the regular smoke detectors throughout the house with combo smoke/CO detectors. there is already a signalling wire so if there is CO anywhere they all go off.

nobody

I think it's worth doing a video on a US hot water heater. When I last visited family in the US, I was surprised to see a chimney lead off from the hot water cylinder, only to notice below that the gas burner heats the cylinder directly. I never saw a hot water cylinder heated directly like that here in Ireland, let alone the UK, i.e. there's a separate gas or oil fired boiler that heats water and this goes through a coil in the hot water tank to heat it (the water doesn't mix). The same boiler heats the radiators during the winter.

Seán Byrne

In the UK we have some domestic items called "boilers". These are hot water central heating systems as an alternative to the hot air variety. Modern ones (combi-boilers) heat the incoming cold water supply to make hot water "on the fly". If the incoming is very cold, an underpowered boiler (e.g. 20Kw) will have to run flat out, whereas as a more powerful one (e.g. 24Kw) will be able to "cruise". Showering comfortably in winter can easily become a casualty of false economies.

Peter Bryenton

The house we lived in until I was eight had a weird combination of forced air and radiator central heating. I used to curl up next to one of the vents with a quilt cover in winter. I've never seen a house with it since in the UK (I'm now 42). I don't think it was furnace based either...no idea how it worked; I kind of suspect there was basically an internal radiator somewhere that had air blown through it.

Chris Crowther

I shall add a pinned comment! It's funny because I feel like I knew this before, and yet when I did a quick sanity check I read something that seemed to suggest it was a thermocouple. I really should have dug further on that one...

Technology Connections

You need to make a correction on the flame sensor. the way it actually works may blow your mind. current limited a/c voltage is sent to that stainless probe you called a thermo couple , then the control board looks for a voltage drop , because the flame actually carries the current to ground through the metal of the burners. I.E. a honeywell board (the ones I've seen ) send 60v a/c current limited one wire to flame sensor probe ( piece of stainless steel rod) then monitors voltage on that wire to verify that indeed the voltage dropped, if for any reason the voltage comes back up to 60v it knows immediately ( with out waiting for a thermocouple thermistor to cool) that the flame is out and to turn off then burner gas valve. if it were a thermister there would be two wires from it to the control board. further more it would no need to be isolated from it mounting bracket. Cheap furnaces use the hot ignitor for flame sense , by checking resistance of ignitor, after it has cooled enough. The ignitors resistance changes with temperature just like a thermo couple. but in your case you do not have a cheap furnace and its obvious you have an ignitor and a flame sense probe.

Jacob Tyler Hooyman

We leave ours off until it hits indoor 59F in Wisconsin. Then I'll set the program to 65-68 night/day.

Joe Hrdina

Is that a heat exchanger then? I feel that he touched on that topic when reviewing the Super Crappy YouTube ad-spam "air conditioner".

Joe Hrdina

I think wood pellet furnaces are a thing, but maybe that's more rural.

Joe Hrdina

Ahhhh...the smell of firing the furnace up for the first time in fall. bleh.

Joe Hrdina

So I'm in Norway, and things could not be much more different. We traditionally use wood for heat, but after WW2 kerosene became very common until electric started taking over from the 70's. Over the last 20 years heat pumps taken over most of the heating for older houses. Various types of waterborne central heating furnaces have been used in larger buildings, while smaller houses have mostly used heaters in individual rooms (or for multiple rooms trough open doors). From January this year it is now illegal to use fossil fuels for heating residential buildings, except where electricity is not available, cooking, in cabins, and with mobile space heaters for backup purposes. Now, since 2010 our building codes require all new residential buildings to be built with active ventilation and heat recirculation to save on power needs. New houses are actually pressure tested to make sure they are air tight. Water-based heated floors with a heat pump are most common, but a backup non-electric heat source is mandatory for most houses and usually takes the form of a fireplace in the Livingroom (larger apartment buildings do not need the backup). Some people also have wood fired boilers, usually in rural areas. Apartment buildings do not need the backup. This make for very comfortable houses, but also cause problems if the ventilation is not used right. Mold and rot will start developing very quickly if the ventilation is turned off, some systems get issues due to people sleeping with open windows, air quality issues is common from people struggling with the control systems, you have to open a window if using the fireplace or it will not burn and some people are just oversensitive and get reactions to the air in those houses. Can you tell I'm not big fan? Anyways, that was a very quick summary of Norwegian heating systems. I thought it might interest some, it's quite different from North America.

Thor Syvertsen

Technically, those are extremely weak EMPs. An EMP is kinda like wirelessly charging your phone, but the wireless charger is broken and gives your phone too much power and breaks it...from miles away.

Stephen Gillie

WA State is much the same - those regtangular in-wall space heaters are everywhere. I've only ever lived in 2 apartments and/or houses with central air. And one 100-year old building with an actual radiator. It's burning hot, in my living room!

Stephen Gillie

Carbon Monoxide alarms are essential. A friend of mine had her alarm go off in the dead of night. She evacuated and called the fire brigade (I’m in the UK). Turns out the restaurant downstairs had installed a wood-fired pizza oven, left it to burn out over night and filled the flats above with carbon monoxide! She could have been killed.

Daniel Andrews

Hi Richard, that is similar to what happens in Manhattan, NYC. They produce steam that is transported underground throughout the city and is used by various buildings for heating/cooling purposes. Some even use it for cleaning but my favourite use is museums that use it to control humidity! https://en.wikipedia.org/wiki/New_York_City_steam_system

Rob Tapp

This video was illuminating. Living in a Nordic country nobody in cities has boilers or furnaces in their house. Hot water is pumped under the streets ( a by product of electricity generation) and the water is used for radiant heating and hot water. No machines to maintain in your house and the temperature of the heating water inversely follows the outside temp, so there is no on-off cycle as the heating tries to keep the room at a steady temperature, the heating just gets warmer and warmer the colder it gets outside. And the "negative pressure" comment is quite funny. In Finland the houses are air tight with heat recovery ventilation now mandatory, any furnace that relied on negative pressure would be in big trouble with such an air tight approach to house building.

Richard Bevan

Here in the UK, the word furnace would only really be used in conjunction with something like a glass works or a steel smelter, so the idea that Americans have a furnace in their house seems strange. It would be like saying "I have an aluminium smelter to heat my house"!

Paul Mansfield

Fascinating! I had always (wrongly) assumed furnace was to boiler as sidewalk is to pavement. I thoroughly enjoyed being enlightened!

Thank you, this answers the questions I had when my parents got a new furnace. It had all sorts of mysterious PVC pipes and a little water pump that occasionally ran to pump mysterious water that collected in a little tank. It all seemed so complex compared to the old furnace, and now I see why.

Happy Spring :-) Interesting video. Furnaces aren’t really a thing here, but it’s very interesting to see how they solved the efficiency problems and managed to keep the dangerous parts of the process fairly separated from the fragile humans! Ewen

Ewen McNeill

The nice foggy weather of San Francisco means my furnace sometimes run during cold summer night. I have no such thing as a "pre-heat season tune up"... thermostat is set all year long at 64 F for the night.

Raphaël

Sparky things create nasty wide frequency radio emissions and is probably not used because of [insert any random radio based thingie here].

Tony Nilsson (The LEEC)

I am _very_ excited for the upcoming heat pump video!

Here in Alaska, where central A/C is all but unheard of, baseboard radiant heat is still very common. I prefer it, actually, as it keeps the living space a very stable temperature instead of the hot cold hot cold that force air provides. Obviously, it's stupid to have both radiant heat AND forced air for A/C, so it makes sense that most areas have just forced air.

Quinton Wilson

If this video had come out last year, it could have saved me the hassle of frantically trying to figure out how my furnace works (and why it doesn't) while also trying to stay warm. It turned out to be the draft inducer motor! It just gave up and quit spinning. But by the time I figured that out I had also switched out some capacitor and even the control board thingy. Still though, in the olden days before the proliferation of accessible hobbyist youtube videos, I would have probably given up and would have to call somebody. And have them come into my house. And TALK to them.

I just ran across a feature on a company that specializes in vertically-drilled heat pump installs. It's essentially the same ordeal as digging a well, but instead of making it a, well, well, you run a coolant loop down and back up. It's minimally invasive since it's just a vertical pipe and not a huge "excavate the whole yard" situation. I'm hoping we get the sort of aggressive policies in place to incentivize these sorts of things, because it's definitely feasible and largely uses well-established (pun indented) techniques. It just needs to scale.

Technology Connections

I hope you are right about heat pumps and geothermal replacing gas (and oil) for heat, but that is going to take some intense political wrangling to enact some sort of government assistance for households to make the changeover. The time I spent working in my state's Heating Assistance office (Minnesota) helped drive home to me something that I'd long been aware of which is that there are large numbers of people living in the northern US (probably also Canada) who either can't afford to replace their heating systems or are at the very least reluctant to make a big one-time payment to install newer efficient heating tech. I didn't know that the light that comes on when your gas furnace is starting was the ignition source, I just assumed that there was a spark igniter in there somewhere, but then that's how they did it back in ye olden dayes.

Mark Hesse

neeeeeat

evistre

On the topic of fresh air by negative pressure. This is an already solved problem by “ERV” and “HRV” systems that are dedicated to being in fresh air usually 24x7 but after filtering and also cooling/warming it with the outgoing air and in the case of the “E” (energy) Recovery Ventilator humidity as well!. Tends to be used mainly in higher end houses currently. Matt Risinger talks about a lot on his build channel. The general idea is to get that fresh air but have it come in on “your terms” and not through random cracks or in the case of his builds the building envelope is generally so tight that it wouldn’t make it in even if you wanted it to. Would make a great video!

Trent Lloyd

I was worried about that with my system (three wire) and went with a sensi and skipped the nest after I bought my house. It worked great. I use an ecobee now but thats because I got a new furnace and a proper c wire installed.

Jacob Nelson

Love the flashing "policy suggestion" haha

Jeremy Whaling

Maybe unrelated...but has anyone else burnt out their relays because they got a Nest and it power-tapped the heck out of it? I ended up ditching the Nest and going with a Sensi (Battery powered)

Keith Boucher

Could be! This wasn't something I dived deeply into.

Technology Connections

I think most modern furnace flame sensors work using flame rectification, not a thermocouple. Thermocouples of course do work too, and were common for monitoring pilot lights. Great video as always Alec!

John Hiesey

My house had resistive coils as its only source of heat for 50 years before I finally replaced the system. Granted I dont live in the intense cold climes.. Nothing beats the smell of dust and dead bugs baking off the coils during the first heat of the year (due to how weird the world has become, I must point out that this last comment is, indeed, sarcasm)

Honorary Octopus

Wow! With Winter coming and all, I've actually been wondering about this! I kind of guessed you'd pivot to this after the Nest video a while ago - thanks for the great video!

Steets