# give me coffee! **URL:** \ **Category:** Factual Questions\ **Created:** [September 7, 2001, 2:58pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234 "2001-09-07T14:58:01Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Lin](https://avatars.discourse-cdn.com/v4/letter/l/13edae/32.png) [@Lin](https://boards.straightdope.com/u/Lin)\ **Post date:** [September 7, 2001, 2:58pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234/1 "2001-09-07T14:58:01Z")
when I pour cold water into the coffee maker, it only takes minutes before it comes out hot…how does it heat up so fast??? ---
**Author:** ![Schadenfreude](https://avatars.discourse-cdn.com/v4/letter/s/ac8455/32.png) [@Schadenfreude](https://boards.straightdope.com/u/Schadenfreude)\ **Post date:** [September 7, 2001, 3:03pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234/2 "2001-09-07T15:03:42Z")
Very hot coils. The heating element in a coffee maker puts out an awful lot of heat for such a small amount of water, thereby heating it quickly. How Stuff Works has pictures: > **[How Coffee Makers Work](https://home.howstuffworks.com/coffee-maker.htm)** > > Every morning you scoop in the coffee, add the water and turn it on, but have you ever wondered what is happening inside your coffee maker? Find out how that precious gadget delivers your wake-up dose. There are residential water heaters operating on a similer principle now. Instead of keeping 50 or so gallons of water hot at all times, water can be run through a short length of very hot tubing to provide hot water on demand. With these heaters, you’ll never run out of hot water, even if you run the shower all day long. Well, never, that is, until you get your energy and water bills. ---
**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\ **Post date:** [September 7, 2001, 3:06pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234/3 "2001-09-07T15:06:09Z")
Get a screwdriver and see for yourself… My coffee maker uses a pretty mundane metal heating element. The “trick”, is that it doesn’t try to heat all the water at once. It just heats the trickle going to the top, the flow being driven by the heating. The overall heat required to get the total volume of water to a certain temperature is the same either way, but the fact that it heats the water in small amounts allows it to produce a flow of very hot water for brewing almost immediately. ---
**Author:** ![MsWhatsit](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@MsWhatsit](https://boards.straightdope.com/u/MsWhatsit)\ **Post date:** [September 7, 2001, 6:14pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234/4 "2001-09-07T18:14:54Z")
**Schadenfreude** : Do you happen to have any info about how hard a water heater like that would be to install, or if it’s possible to replace an old-style water heater with one of these newfangled ones? I’m curious, as our water heater really sucks and I’m tired of never having hot water. ---
**Author:** ![breaknrun](https://avatars.discourse-cdn.com/v4/letter/b/bbce88/32.png) [@breaknrun](https://boards.straightdope.com/u/breaknrun)\ **Post date:** [September 7, 2001, 7:37pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234/5 "2001-09-07T19:37:04Z")
**MsWhatsit** , do a search on tankless water heaters and I think you’ll find your answers. I checked out the site linked above and that site had some links to a couple companies. [Controlled Energy](http://www.controlledenergy.com/) and [HeatStream](http://www.heatstream.com) are 2 such companies that sell tankless water heaters. Thanks for the posting that link **Schadenfreude** , I am now considering one for my jacuzi which takes about 80 gallons. woohoo! 🆒 ---
**Author:** ![lestrange](https://avatars.discourse-cdn.com/v4/letter/l/aca169/32.png) [@lestrange](https://boards.straightdope.com/u/lestrange)\ **Post date:** [September 7, 2001, 7:55pm UTC](https://boards.straightdope.com/t/give-me-coffee/80234/6 "2001-09-07T19:55:09Z")
I’ve seen ads for tankless water heaters–can anyone say if they’re any more efficient than the regular kind? they sound like they would be, but that’s not always the best way to judge, is it. so do tankless water heaters really save money or energy?