Replies

1. 
   WayneL5 | Sep 15, 2009 04:50am | #1

   In a couple of months condensing gas water heaters will be available in the U.S.  They are available in Canada now.  They are about 90% efficient compared to about 60% efficient for normal water heaters.  The recovery rate is so fast that you essentially would not draw water fast enough to run out.  The downside is that they don't come in 40 gallon size and cost over $2000.  But they are likely eligible for energy rebates, and they are of very high quality and will last a long time.

1. 
   tombuilder | Sep 16, 2009 01:35am | #3

   Thanks Wayne.Off to the land of web research.

1. 
   NRTRob | Sep 16, 2009 04:52pm | #6

   those water heaters have been available in the states for over 15 years now (Polaris, these days we have the Phoenix, Vertex).but they are pricey for sure.question number one is how much hot water are you using now? do you know?-------------------------------------
   -=Northeast Radiant Technology=-
   Radiant Design, Consultation, Parts Supply
   http://www.NRTradiant.com

1. 
   tombuilder | Sep 17, 2009 03:03am | #7

   Peak first hour is as generous 140 gallons.

1. 
   NRTRob | Sep 17, 2009 05:06pm | #15

   first hour isn't a useful number.what is the actual load here? two simultaneous regular flow showerheads? low flow? multiple sets of back to back showers? jacuzzi tub of x gallons?-------------------------------------
   -=Northeast Radiant Technology=-
   Radiant Design, Consultation, Parts Supply
   http://www.NRTradiant.com

2. 
   tombuilder | Sep 18, 2009 02:01am | #18

   Two regular flow shower heads and one dishwasher is probably the worst case scenario.

3. 
   NRTRob | Sep 18, 2009 04:12pm | #22

   to do two regular flow heads and a dishwasher, for two sets of showers back to back, you'd need about 100k of output and 80 gallons of storage, storing at 140. for a single set plus recharge period before a second set, you could do 30k output with an 80 gallon tank, or 90k output and a 50 gallon tank, just to give some sample numbers.Drop the dishwasher and you've better off to some degree.now the questions is daily volume of usage, so you know how big a deal efficiency improvements are, or are not.-------------------------------------
   -=Northeast Radiant Technology=-
   Radiant Design, Consultation, Parts Supply
   http://www.NRTradiant.com

2. 
   danski0224 | Sep 15, 2009 02:12pm | #2

   AO Smith Vertex.

1. 
   Hiker | Sep 18, 2009 04:03am | #19

   Have you used one?  I am very interested in them but have not had a chance to spec one.  Any feedback would be greatly appreciated.

   Bruce

1. 
   danski0224 | Sep 18, 2009 05:32am | #20

   Not personally, but a plumber I know told me that they work great.

   Better than a tankless.

1. 
   Hiker | Sep 18, 2009 02:25pm | #21

   Thanks for the info.

3. 
   MSA1 | Sep 16, 2009 02:17am | #4

   Ive got a duplex. We had one forty gallon gas WH and it wasnt enough, I put a 50 gal electric (in series) after the gas. Not one complaint and no appreciable increase in the electric bill.

   I essentially added a holding tank. Since the water comes in hot it doesnt cost much to keep it that way.

    

   Family.....They're always there when they need you.

4. 
   Clewless1 | Sep 16, 2009 04:29pm | #5

   What is a 'two-flat'? Duplex? The existing are piped in a series?

   The concept is fine ... high efficiency and large tank would do you well. I bought a medium efficiency Bradford White w/ plastic flue and induced draft combustion. It's loud, so needs some sound attenuation for the room.

   Recirculation pump ... good idea, but put a control on it to limit its use. You could put a switch or crank timer in each kitchen to control it ... or some such.

5. 
   popawheelie | Sep 17, 2009 03:14am | #8

   I recently got a gas Bradford white that had 2" of foam instead of one.

   Everything else about it was pretty conventional except it is a Bradford White.

   I think they are a step up in quality from most water heaters.  

   "There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."
   Will Rogers

   
   

   ---

   Edited 9/17/2009 11:22 am by popawheelie

6. 
   junkhound | Sep 17, 2009 03:25am | #9

   After 37 years, replaced the 52 gal electic last year. 

   $70 bottom of the line replacement, same as the original. Eelectric.

   Installed in an elevated plywood box, R19 insulation added all around. Left on vacation and only used 2 kW-hrs over 2 weeks keeping it at 120F (have a meter on the input).

   Need to build a HP from surplus wallbanger parts when I retire for the water heater, use the heat from the back coils on the fridge and freezer.

1. 
   McPlumb | Sep 17, 2009 02:08pm | #10

   I asked our HVAC guy about tying the Geo, refridge,and freezer together. At the time he said the one drawback was, they each used a different refridgerant. Should be a great setup if you can work out the details.

1. 
   DanH | Sep 17, 2009 04:15pm | #11

   I suspect the best way to make it work would be to use an intermediate heat exchanger, so that the fridge and freezer would pull from the HP like a domestic water heater on a hot water heating system.
   As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz

2. 
   junkhound | Sep 17, 2009 08:37pm | #17

   they each used a different refridgerant

   Nothing commercially available I know of, that is why it has to wait for 'retirement'.

   Had to design/build my own HP, could not find anything  to buy that gave a COP of near 6 without getting a 'ream job'. on cost plus needing to put a big box someplace.

    

2. 
   davidmeiland | Sep 17, 2009 04:22pm | #12

   Bonus points if you can also capture the waste heat from the dryer vent.

1. 
   DanH | Sep 17, 2009 04:24pm | #13

   Of course, you can buy HEs to capture drain waste heat now.
   As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz

1. 
   davidmeiland | Sep 17, 2009 04:27pm | #14

   Those are very cool. They won't fit just anywhere, but look for more stuff like that coming along that's easier to use.

1. 
   DanH | Sep 17, 2009 07:51pm | #16

   The downside of them is that they're really only effective for showers and sinks, not tubs or washing machines.
   As I stood before the gates I realized that I never want to be as certain about anything as were the people who built this place. --Rabbi Sheila Peltz, on her visit to Auschwitz