gas condensing water heater?

[Feuerstein]

Time for me to look for a new water heater, the old one is going to blow at any moment.

Been reading about "gas condensing water heaters" which raised my interest since using the "waste heat" just seems to make a lot of sense.

Can't find much about them though. Apparently there are some made by A.O.Smith (Vertex?) and GE. Supposedly they should have gone mainstream in 2009 or thereabouts.

Does anyone know where they are sold? I need one that can handle hard water. Any first hand experiences? Worth the premium over regular tank heaters? Can they be installed pretty much the same way as the regular ones?

 

[napaAl]

Check out Navien, from Korea.

 

[Feuerstein]

I should have made it more clear - not looking for a tankless unit at this point, rather a gas tank heater that makes better use of the waste heat ("condensing").

Looks like nobody has them or knows anything about them.

 

[HoosierBuddy]

I'm not sure if anyone makes a fully condensing tank-style natural gas water heater or not.

If they don't, it's because the biggest gain in efficiency that can be made on a water heater is to eliminate the tank. A standard-tank style water heater (with a metal vent) is rated at something on the order of .60 energy factor even though the burner is around 80% efficient, just because of the standby losses.

The newer tank-style gas water heaters that are energy star rated are (I think) about .62 energy factor or better. Really not enough differences to even notice, to tell you the truth.

Meanwhile, a fully condensing TANKLESS water heater probably comes in at around a .85 energy factor, because you've eliminated the standby losses associated with the tank itself.

Personally, I'm still using an old-style tanked water heater. While it's NOT the most efficient on the market, with 3 kids that only leave the shower when the water gets cool, I don't think an "unlimited amount of hot water" is a GOOD thing...AND I like the fact that my water heater will operate properly even with no electricity. Anything more modern, like a power vent model, won't fire without power. They are simple and reliable and most tank style water heaters (with a standing pilot) don't require any service during their lifetime. Eventurally, they rust through, leak water, and then it's time for a new one.

The last one I changed out took me about 2 hours total...and I'm slow.

Phil

 

[moserjj]

I am entertaining the idea of putting one of these in my new house currently being built:

http://www.hotwater.com/water-heaters/residential/conventional/gas/vertex/power-direct-vent/

I don't want a tankless either with all of the common issues and the fact my plumber despises them and basically won't install them

 

[6768rogues]

I like the old fashioned gas water heaters, too. A modern unit works the same way with more insulation on the tank, so it is better use of an old technology. I don't worry about the pilot light because it is helping to keep the water warm.

 

[59 wagon man]

i have a rinnai gas condensing tankless and effiency was up in the 95% range . is there a reason you want to stay with a tank other than your plumber's feelings. i do a far amount of tankless heaters both gas and electric and have seen a lot of problems to be installation or poor planning. they are much better then 10 yrs ago when they first came here . back then it was a struggle to make warm water forget about hot

 

[6768rogues]

My natural gas bill to run a 40 gallon regular tank type water heater is about $30 per month. The water heaters are cheap and last at least 10 years with our water. If I were to save half of the energy cost with a tankless heater, it would take too long to recover the up front cost.

 

[Jackfre]

When I replaced my tank with a tankless my gas consumption dropped by 60%. I know that number is good as all I do with gas in the summer is hot water. I've represented Rinnai for 21 years and have sold in excess of 100,000 of their units in my market. I've trained thousands of contractors on these units. The vast majority of problems are install related. Out of the box reliability of the equipment is outstanding.

Check your water quality. If there are problems there, either treat the water or walk. Number one problem with tankless installs is inadequate gas line sizing, by a wide margin. Next is improper venting/location/piping and on and on. The units themselves, most manufacturers, are excellent but there are exceptions.

My experience is that the plumber who "hates" tankless is a guy who has not, technically, kept up with his industry or has not taken the time to become properly trained in their application.

 

[junk4dummies]

There you go. You are dead on. Tankless water heaters are the only way to go. The brand you state is a very good brand. There are some **** brands and you would be supprised who they are. You would expect better from those companies.

The rest of the world has been using tankless for 70 years or more. I have traveled all over the world have used them in places you would not expect to see electicity. My wife is 72 and used them In Australia back inthe 40's.

You are right. If you find someone who does not like them you have someone that is ignorant of the facts and has not been trained. Some people live in the stone age. That is why there are third world countries. It boggles the mind.

Hot water on demand is the only way to go. Just make sure you get one large enough to fit your needs and is installed properly. That is all I recomend as an Architect.

They do save you money. You don't need a plumber to install one properly. They don't put out the heat a tank does and if the heater is in the house that can cost you more in AC.
They last for years and years. They are easy to repair and parts are easy to get. My wife's aunt in Sydney has been using the same one sense the late 50's. Good hot waters heaters are $500 or more. You will go though 2 to 4 of them in the same length of time a tankless will last. I have them in my appartments and comercial rentals. They take less space and never need draining. They have made good ones for years. The brands that first hit the American market big time where ****. I used my first one over 30 years ago in my farm house and it is still working just fine.

I am not a green person. That is all BS. I like them becasue they save me money. They do not generate a lot of extra heat in the house, laundry or basement. Just my 3 cents worth.

 

[sprntpshr]

Check out Polaris water heaters, we used to instal them for combo heating and for standalone space heating. Condensing, uses 2" plastic venting and has a stainless steel tank and heat exchanger.

The only concern would be the hard water. Would be best to contact the manufacturer and ask about the max grains of hardness accepable.

It is not a tankless heater.

 

[danski0224]

I'm not sure if anyone makes a fully condensing tank-style natural gas water heater or not.

AO Smith Vertex.

 

[BadgerBoilerMN]

If they don't, it's because the biggest gain in efficiency that can be made on a water heater is to eliminate the tank.
Phil

The "biggest gain" is to eliminate the 350°F stack temperature and vent with PVC at 100°F. The standby losses from a fully condensing, sealed combustion domestic water heater like the Polaris of Vortex about 1/2°F/hour.

They also lend themselves nicely to combination space and DHW heating (don't try this with a "tankless" water heater). We use them every day to replace the old 80% Bradford White CombiCor water heaters in our radiant floor heating business, eliminating drafty chimneys and high fuel bills.

 

[danski0224]

The "biggest gain" is to eliminate the 350°F stack temperature and vent with PVC at 100°F. The standby losses from a fully condensing, sealed combustion domestic water heater like the Polaris of Vortex about 1/2°F/hour.

Just to clarify, a plain old PVC vented induced draft water heater without a condensate drain is not much more efficient than a regular one... 62% vs 59%.

You do not have stack losses from a plain PVC vent water heater, but you more than make up for those gains with the massive amount of dilution air- which eventually comes from outdoors in a single pipe system.

A direct vent (2 pipe) Vertex is something like 96% efficient. It also has a condensate drain.