On Water Heaters

So if you go to buy a new, standard, tank-type water heater, you discover that for any given gallon capacity they come in several different tank shapes, called “short”, “medium”, and “tall”.  It seems the “tall” are marketed for use in narrow spaces, the “short” for use in low spaces (like a crawlspace), and the “medium” for, well, everything else.

The interesting thing, though, is that from an efficiency (passive heat-loss minimization) standpoint, there is an ideal cylinder shape– namely, the one with the smallest ratio of surface area to volume, which is when the diameter is the same as the height.  From this standpoint, the shorty models are almost perfect, but the mediums are too twice too tall, and the “talls” are even worse.  Based on this, it would be rational to buy a short one– except that, for some reason, the shorts and talls are both much more expensive than a medium (like, $50-100 more)!  This makes no sense from a materials perspective, since the shorts use less steel/glass/insulation than a medium, and a medium less than a tall.  So I suppose it must have to do with demand, volume of production, and manufacturing efficiency.

 

About these ads

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Follow

Get every new post delivered to your Inbox.

Join 81 other followers

%d bloggers like this: