Is a Peltier Device efficient ?

Xringer · 07-25-10, 09:55 AM

I know my Sanyo ASHP (Air Source heat pump) is much more efficient than using electric (resistive) space heaters..

And it seems like a Peltier device is really a heat pump..

So, my question is, what would be more efficient to heat a water tank,
a resistive load? Or a Peltier device? (Given the same wattage input).

Assuming the air temperature in my basement is between 65 and 72 degrees F.
And, surface of the metal water tank will normally already be warm.
Between 100 and 150 deg F.

This heater is Ebay item # 190415274674

Daox · 07-26-10, 06:12 AM

Last I checked peltiers are generally ~8% efficient. So, unfortunately they are horrible for almost any application.

Xringer · 07-26-10, 08:07 AM

I looked around and found conflicting information. I think one youtube video said the
COP was around 2.6 (for heating) and then other people said it was 0.6 to 0.8 COP.

I once used an Ebay CPU cooler to convert a little portable 6-pack cooler,
but never gave it a good test, because I didn't have a 12V PS at work, with enough amps..

Just wanted to keep my lunch bag from spoiling.

NiHaoMike · 08-01-10, 11:33 AM

Just yesterday, I saw a tabletop water heater (for making coffee and stuff) at a Chinese store that claims to use only 17W with advanced semiconductor technology. It's pretty expensive at $180 for a little unit, though.

07-25-10, 09:55 AM	#1
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Is a Peltier Device efficient ? I know my Sanyo ASHP (Air Source heat pump) is much more efficient than using electric (resistive) space heaters.. And it seems like a Peltier device is really a heat pump.. So, my question is, what would be more efficient to heat a water tank, a resistive load? Or a Peltier device? (Given the same wattage input). Assuming the air temperature in my basement is between 65 and 72 degrees F. And, surface of the metal water tank will normally already be warm. Between 100 and 150 deg F. This heater is Ebay item # 190415274674

07-26-10, 06:12 AM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Last I checked peltiers are generally ~8% efficient. So, unfortunately they are horrible for almost any application. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-01-10, 11:33 AM	#4
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Just yesterday, I saw a tabletop water heater (for making coffee and stuff) at a Chinese store that claims to use only 17W with advanced semiconductor technology. It's pretty expensive at $180 for a little unit, though. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

07-26-10, 08:07 AM	#3
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I looked around and found conflicting information. I think one youtube video said the COP was around 2.6 (for heating) and then other people said it was 0.6 to 0.8 COP. I once used an Ebay CPU cooler to convert a little portable 6-pack cooler, but never gave it a good test, because I didn't have a 12V PS at work, with enough amps.. Just wanted to keep my lunch bag from spoiling.