Replies

1. 
   davidmeiland | Dec 22, 2007 07:34pm | #1

   http://www.marathonheaters.com/

2. 
   BillHartmann | Dec 22, 2007 09:02pm | #2

   Electric water heaters are easy to compare on operating cost.

   Look at energy factor. That is bascially a ratio of energy used to hot water produced. For gas that includes the burner losses.

   But for electric the only losses is the standby loss, the heat loss through the insulation.

   While a good water heater there are other that are equal or stlight better energy factors. But they are conventional "glass" lined metal and have "limited" lifetime. But I have no idea of the cost of the Marathon.

   Here is list of a all of the electric water heaters along with their energy factor and the heater size, which affects recovery rate.

   http://www.gamanet.org/gama/inforesources.nsf/vAttachmentLaunch/0E661AB59EFE122B85256E90006078B4/$FILE/12-07-elec-rwh.pdf

   Here is other information on water heaters and operating cost.

   http://www.aceee.org/consumerguide/waterheating.htm
   http://www1.eere.energy.gov/femp/procurement/eep_electric_waterheaters.html
   http://www1.eere.energy.gov/femp/procurement/eep_waterheaters_calc.html
   http://www.srmi.biz/Tips.Water_Heating_and_Conservation.Buying_an_Electric_Water_Heater.htm

   This links to list of energy rates for a number of different types of water and space heating equipment.

   http://www.gamanet.org/gama/inforesources.nsf/vContentEntries/Product+Directories?OpenDocument

   .
   .
   A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
3. 
   frenchy | Dec 22, 2007 09:39pm | #3

   homedesign.

     Note that 40 gallon water heaters and 80 gallon water heaters have the same watt elements in most cases.. all you do with bigger water heaters is heat more water for about the same energy costs..

     That gets to be important with electric water heaters because of the slower recovery rate they have..

    if everyone takes a shower in the morning with the larger one you might not run out of hot water while with the smaller one you most likely will..  

     What I think happens is say you drain off 20 gallons for your shower and your wife steps in 10 minutes later.. well the tank gets 20 gallons of 55 degree water and that drops the temp to say 70 dgrees.  It can't recover that quickly so she may wind up with a cold shower. While if you have an 80 gallon tank and you use the same 20 gallons that 20 gallons won't drop the water temp that much because there is still 60 gallons at 130 degrees.   the 20 gallons you used won't drop the tank temp below say 100 degrees and then the elements will quickly raise that up to hot enough so she doesn't feel chilled..

     Now when I use my water heater for in floor radiant heat I use a 40 gallon water heater because in addition to the 40 gallons I may have a hundred in the tubing.  I want that 40 gallons to warm up quickly   due to mass it takes longer for 80 gallons to warm up than it would take 40 gallons..