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Halfbakery

halfbakery.com

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Re: Halfbakery

#51

Post by frankus »

freedomben wrote: post #33
Tuna-Fish wrote: post #17

Earlier quoted context omitted.

My brother uses an on-demand electric water heater he built himself (he is an ee) and it works just fine. Also, it's less expensive to operate than a tank-type heater, as there is no cooloff loss.

I tend to think cool off loss is much less of a problem than people think. The insulation around those heaters is incredible. I once turned off my water heater before leaving on vacation, and when I got back after a week the water in the tank was still probably 10 to 15 degrees F warmer than room temperature.

Also in a lot of cases (cool climate, electric resistance heat, water heater inside conditioned space) that heat isn't really lost, it's just offsetting heat that would have come from something like an electric baseboard heater.

Re: Halfbakery

#52

Post by mavhc »

Tuna-Fish wrote: post #17
gjem97 wrote: post #14

Earlier quoted context omitted.

On-demand water heaters are really only feasible if you have natural gas or propane heat in your house. The electric ones are quite feeble and expensive to operate. This is a good idea. My intuition though is that the additional up-front costs of this type of setup would be enough of a barrier that adoption would be slow.

My brother uses an on-demand electric water heater he built himself (he is an ee) and it works just fine. Also, it's less expensive to operate than a tank-type heater, as there is no cooloff loss.

I have an on demand 10kW water heater, it's my shower.

Re: Halfbakery

#53

Post by fragmede »

rockostrich wrote: post #18
al2o3cr wrote: post #16

Earlier quoted context omitted.

There was a pretty successful Kickstarter a while back for a product ("Coffee Joulies") that was exactly that, but for your coffee mug. Little bean-shapes made of stainless steel, filled with material that changed phase at 140F.

There's also Ember [1] (also a kickstarter I think) that just made a mug with a heating element and controller to keep your beverage at a specific temperature. Using materials with specific phase change temperatures sounds like an innovative solution, but it's also grossly engineering a problem that can be solved better by $10 worth of components. [1] https://ember.com/products/ceramic-mug

Is having a processor and electronics and software and sensors, which, despite the cost of components of $10, requires electricity. Is that really that much better than just building a better thermos?

( These things are amazing; if you haven't experienced one yet I recommend picking one up from REI: https://www.yeti.com/drinkware/rambler-20-oz-tumbler/YRAM20.... )

Re: Halfbakery

#54

Post by johnnyforeigner »

mlkmt wrote: post #19
johnnyforeigner wrote: post #11

Half Bakery is some awesome old-skool internet stuff. Back in the late 90s it was one of my favourite haunts. Sadly they lost all their content somehow and didn't have a full backup so, funny though it is now, there was some epic stuff on the old site that is lost forever.

I remember browsing it in the 90s... remember any epic stuff from back then?

Always loved "Film Noir House" where every room was wired such that it narrated whatever you were doing around the house, but in the style of a Film Noir movie... "He walked into the bedroom... switched on the light..."

Re: Halfbakery

#56

Post by sehugg »

derefr wrote: post #47
yawz wrote: post #37

Earlier quoted context omitted.

Wow! A blast from the past. I started my career in the mid-90s writing software with exactly this same stack.

It's funny—you just need a cgi-bin: 1. with 1777 permissions (sticky bit set); and 2. rsynced between a cluster of systems; and you've got a modern Function-as-a-Service backend.

And of course you want to use a flat file database on an NFS server, maybe using some cool flock()s to synchronize writes :)

Re: Halfbakery

#58

Post by smueller1234 »

sehugg wrote: post #56
derefr wrote: post #47

Earlier quoted context omitted.

It's funny—you just need a cgi-bin: 1. with 1777 permissions (sticky bit set); and 2. rsynced between a cluster of systems; and you've got a modern Function-as-a-Service backend.

And of course you want to use a flat file database on an NFS server, maybe using some cool flock()s to synchronize writes :)

Only to then realise that naive flock() won't cut it on your basic NFS setup so you resort to bizarre tricks like using hard links to the lock file to emulate proper locking on NFS because they can tell you which of the racing clients won. Those were good times... right?

Re: Halfbakery

#60

Post by luckystarr »

zelos wrote: post #10

That's kind of clever: http://www.halfbakery.com/idea/Eutectic_20water_20heater#151... Although rendered kind of pointless with modern on-demand boilers.

There are actually companies manufacturing these things but mainly to increase heat-storage capacity of water tanks for solar heating elements. They use thiosulfates (the stuff in hand warmers) or paraffin wax.
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