electric central heated home, could cob mass benches be built over vents?

So here's my idea, to build a cob bench with venting tubes running through it like in a Rocket Mass Heater but have the heat source be the floor vents from my electric central heating unit. I'm thinking that then I could turn it on every few days to re warm the cob. I'm thinking it could just come out the end of bench after the trip around inside the bench, since it normally vents into the room. Would this work?

Yes, but unless you are on time of use billing or have solar/wind that produces excess you want to store I fail to see the benefit other than a warm place to put your tush.

Do you think I could get any radiant heat by doing this? or at least lower my bill? A warm tush is nice, but I'd also like to be warm walking around the house, and turn off the furnace at least every other day. Possible or pipe-dream?

If the idea is to keep the house heated similarly to the current regimen then I don't see a benefit. If however you are looking to keep the house cooler but have small area's to sit and be warm then yes it might. Others here may have a different answer so keep looking.

I'll bet your right..thanks Max I feel OK calling this resolved, thanks for your honest opinion.

Do you think it makes any difference if you heat the Mass with wood or electric? A mass is said to hold the heat for a long period of time to keep your home heated. Then a Mass would be more than a bed or a place to sit. How hot it would get would be something else.

I think I just came to the realization that if I'm willing to build a cob bench we may as well go all the way and do it right and make it a RMH ..I mean really what was I trying to keep shoddy heater for??, except it's here and keeping the mobile from molding for the time being.

adding a rocket mass heater to many homes just is not a simple thing...very unfortunate.

The idea of the rocket mass heater is that it uses the wood very efficiently so that it burns very completely and after the burn the exhaust is put through a mass which absorbs most of the heat and radiates it slowly out into the space over a long period of time. It is actually in some sense gathering the heat which would go up into the exhaust on old fashioned wood burning stoves.

You have electric heat, this, as far as i know, does not generally exhaust much heat out of the house at all so there is no place to trap take the heat from to redistribute back into the house. The most immediate place I can see to save a large amount of money in heating is to not heat the rooms which are not being used as much, space heating the area you are using. This could greatly reduce your electric costs. Electric is a very expensive way to heat a house so I assume you have no gas service to use.

If you like the idea of the rocket mass heaters but you find yourself in a conventional house with say wood floors and plaster walls which are really not conducive to rmh, you might want to think in terms of a slightly different approach such as the masonry stove, a fireplace which reroutes the heat through tunnels or brick to extract the heat or this gem I ran into a few days ago:

http://www.geopathfinder.com/9597.html

where they take a traditional cast iron wood burning stove and have the heated exhaust go through a long pipe lined with bricks. The principle of all these heaters is the same, retain heat by absorbing from exhaust of a wood burning unit and allow it to radiate back into the room.

I am afraid each of these other units are much more expensive to build than a RMH but they are earth friendly too.

Thank You Laura..it was a goofy idea really. Economy is the main consideration, and using what I already have is always my jumping off point. Thanks I'll check out the link, I love some of the masonry designs I have seen in the past years, but kind of out of scale for our single wide mobile home, RMH would fit better in our space and we can do it.
Many Thanks,
Wilde Hilde

Cob benches are very heavy, the reason they are able to store heat. They are most likely on a solid foundation like concrete or an earthen floor. A Mobile may not support this mass.