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still thinking about new water heater - gas or hybrid??

Tying to compare a hybrid heat-pump type water heater to a condensing gas tank type water heater, particularly with respect to efficiency. the Heat-pump type has a $500 BGE rebate, and installation would be far easier.
Looking at a Rheem XE80T10HD50U1 (EF 3.7) or 80 Gallon Accelera 300 E Residential Heat Pump Water Heater
from Stiebel Eltron (EF 3.39 Vs a gas unit (condensing?)
i do not know which if the heat -pump type is more efficient than condensing gas, and which is less expensive to operate. The benefit of the heat pump hybrid is that I can place the HWH next to the behemoth furnace in the basement drawing some heat from the metal run of the furnace flue. Condensing gas I would have to relocate and have to run a new vent and breather.
Have an undersized 40 gal normal gas tank heater installed in 2008. Even with water saving shower heads we cannot get two consecutive showers. At some point I will have to replace, but may wait until failure,
I asked here on the forum before about condensing gas tank type vs tank-less. Naturally the puppet movie was shared - It is funny I have to admit.
https://forum.heatinghelp.com/discussion/157853/age-old-question-tank-vs-tankless#latest
Here is the rub - a tank-less heater will require me to change my gas meter thanks to my IMMENSELY over sized 1969 American Standard boiler rated for 750 EDR with 400 EDR of radiator surface area. We have a gas dryer (22 k BTU), gas water heater (40 k BTU), and a gas cook top (50 k BTU) in addition to the gas boiler (300k BTU). This totals 412 k BTU on a 415 CCF gas meter. I have thoroughly cleaned the boiler and I am working on a solenoid on the vent to create natural vacuum and process controller to increase efficiency and prevent cycling on pressure (usually only happens when trying to raise temp too much). I see no reason to replace the boiler unless it shows some sign of failure.
Putting in a tank-less therefore means a new bigger meter. I would prefer not to have to pay BGE to do that, so I would not consider a tank-less unless the furnace has already been replaced.
thanks to the group for sharing your knowledge
Looking at a Rheem XE80T10HD50U1 (EF 3.7) or 80 Gallon Accelera 300 E Residential Heat Pump Water Heater
from Stiebel Eltron (EF 3.39 Vs a gas unit (condensing?)
i do not know which if the heat -pump type is more efficient than condensing gas, and which is less expensive to operate. The benefit of the heat pump hybrid is that I can place the HWH next to the behemoth furnace in the basement drawing some heat from the metal run of the furnace flue. Condensing gas I would have to relocate and have to run a new vent and breather.
Have an undersized 40 gal normal gas tank heater installed in 2008. Even with water saving shower heads we cannot get two consecutive showers. At some point I will have to replace, but may wait until failure,
I asked here on the forum before about condensing gas tank type vs tank-less. Naturally the puppet movie was shared - It is funny I have to admit.
https://forum.heatinghelp.com/discussion/157853/age-old-question-tank-vs-tankless#latest
Here is the rub - a tank-less heater will require me to change my gas meter thanks to my IMMENSELY over sized 1969 American Standard boiler rated for 750 EDR with 400 EDR of radiator surface area. We have a gas dryer (22 k BTU), gas water heater (40 k BTU), and a gas cook top (50 k BTU) in addition to the gas boiler (300k BTU). This totals 412 k BTU on a 415 CCF gas meter. I have thoroughly cleaned the boiler and I am working on a solenoid on the vent to create natural vacuum and process controller to increase efficiency and prevent cycling on pressure (usually only happens when trying to raise temp too much). I see no reason to replace the boiler unless it shows some sign of failure.
Putting in a tank-less therefore means a new bigger meter. I would prefer not to have to pay BGE to do that, so I would not consider a tank-less unless the furnace has already been replaced.
thanks to the group for sharing your knowledge
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Comments
You can go with even lower flow shower heads. If you take tub baths, the dump load is big, so more storage makes sense. I'd lean towards a heat pump, but with an 80 gallon rather than smaller tank as it will operate in heat pump mode most if not all of the time. Research has shown that the bigger HP tanks are more energy efficient.
Use energy cost as a surrogate for efficiency. Which fuel will cost you less? Also, I don't know just how long HP water heaters will last compared to condensing gas. Both are complex. In either, make sure to check the anode in the tank if it's a glass lined unit. That's a start
Yours, Larry
I was leaning toward an HTP Phoenix light duty Light, but saw the failure rate being way too high - in this case @jacobsond you seem to be right that sometimes simpler is better.
@Larry Weingarten - we are already on-board with the shower heads. "Even with water saving shower heads we cannot get two consecutive showers."
I agree with the 80- gal HP option if we go in that direction. I am one of the few that actually changes anode rods.
I'll try to see what gas costs vs electricity.
@jacobsond The simple answer to your question of why not a new tank is efficiency, ease of installation, and total value. The original post did not mention a height issue that exists for the flue. I can't use a unit any taller that the 40 gal one I have. Using a condensing gas solves that problem with a new "flue", but using a HP solves that problem and my behemoth furnace issue by moving to all electric.
As far as lasting longer, I have already replaced the burner assembly as it failed. I think the HP units have a 10 year warranty. The existing unit seems to be too small and runs often.
Yours, Larry
Albert Einstein
They're also useful in a situation where you need to cool the space in which the unit is located.
That said... they're not cheap. The maintenance needs to be faithfully attended to. And they need to either have large tanks or have restricted water use, as recovery is slow -- unless they have auxiliary fuel or electric resistance elements. And in that case, why?
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
That leaves you with hybrid or traditional gas heater. The traditional heater will produce more hot water. They usually produce around 32,000 Btu vs Hybrid at around 16,000 Btu. With 80 gallons of storage this may not be an issue.
You have already figured out that there is no free heat with a hybrid but it sounds like your space has some heat to give up. Depending on your usage habits, you may never see the advertised 3.7 COP. With back to back showers, it will go into pure electric mode and give you a 1.0 COP for that period.
At the end of the day, it will probably cost you the same to run a conventional tank heater as the hybrid. The tank model will require less maintenance and cost less up front. I would probably get one of those fancy new ones with the electronic ignition and damper to reduce heat loss. http://www.whirlpoolwaterheaters.com/learn-more/gas-water-heaters/6th-sense™/energy-efficient-gas-water-heaters/
Albert Einstein
Check for first hour ratings and constant ratings, water heaters are rated by how many gallons per hour they can put out, a heat pump WH is only a more efficient electric unit, IT HAS NO REAL IMPROVEMENT ON SUPPLY OR RECOVERY or gallons per hour.
average 50 gal Hydrid, first hour rating 66 gallons, recover suspiciously NOT GIVEN but they tend to be as low as a standard electric which is below 10GPH
Tankless is a viable option.
You need to know your usage per hour and minute, the only way you're going to get what you need is with an indirect piped to your present boiler, then down the road get a new high efficiency boiler properly sized.
For some comparison here are the ratings for Superstor Indirect water heaters.
SSU-20 first hour-121 GPH SSU-30 first hour 154 GPH
SSU-45 first hour 212 GPH
http://www.htproducts.com/superstor-ultra-waterheater.html
Now that you now your GPH and GPM, you can compare units for supply capability, if it's hard to find on a website they are hiding it because it isn't good, they will focus you on efficiency and savings, you need to have your GPH and GPM then pick out the most efficient unit that will supply that.
Was the 40 gallon heater always a problem?
I ask, because a bad dip tube can make a good water heater seem like it always runs out of hot water.
Our 50 gallon power vent can do two showers no problem. Of course there's a lot of variables. Length of shower, type of shower head, incoming water temp and the temp you run the heater at. My heater runs around 140-145, and plenty on here bash me for it.
Good point about the dip tube. An average gas fired WH puts out about 70GPH, but two showers running 2.5GPM each can out run it in 12-15 minutes.
"72°F Mechanical, LLC"
Or email John at [email protected]
John is the Boilers and Hydronic Heating Systems Course Instructor at NYC's Mechanics Institute, a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
For residential service and installations in New Jersey, please see Toro Plumbing & Mechanical and fill out our contacts page, upload pics, and submit, or call (973-672-1000).
@JohnNY I think this is what I was getting at. Which is more thermally efficient and which is more efficient from an amount of fuel used and cost of fuel needed
the 40 gal heater has always been an issue. I know it was not maintained. I have flushed it and replaced the anode rod, and replaced the burner that died. I thought I checked the dip tube and it was fine. I suspect there is some sludge on the bottom I can't get out.
Recently I changed the shower heads and that helped significantly. It is 10 years old though and within a few years I assume I will have to replace it. Even when turned to very hot it is not very hot. Maybe a dirty thermostat sensor?
The hybrid solves my gas meter problem over a tankless
I also have to be careful on height for a gas unit to to the flue, and the hybrid fixes that issue. the gas piping is a mess, street elbows and galvanized pipe to the HWH.
The hybrid has the luxury of being next to a huge boiler in the winter.
What i'd love to see is a hybrid with a gas backup - but I have not seen one.
Do the bucket test.
The control logic to kick on the gas burner might be a challenge in a dual fuel HP tank.
There were a few manufacturers that built solar (indirect) tanks with gas backup, but the market never really took off. Maybe a dual fuel HP with a gas burner would? Or build your own.
Know that adding a burner, and a hole up through the center of the tank will cost some additional standby losses
trainer for Caleffi NA
The magic is in hydronics, and hydronics is in me
https://homedepot.com/p/Westinghouse-50-Gal-Ultra-High-Efficiency-High-Output-10-Year-76-000-BTU-Natural-Gas-Water-Heater-with-Durable-Stainless-Steel-Tank-WGR050NG076/205625740?cm_mmc=Shopping%7CG%7CVF%7CD26P%7C26-10_WATER_HEATERS%7CNA%7CPLA%7c71700000033150351%7c58700003868932468%7c92700031086624044&gclid=CjwKCAjw1ZbaBRBUEiwA4VQCIYiElQF984UpIQVagFvTQfCFaSoMYwmbCReKj7TqmVZpQTxbqH8B-BoC0loQAvD_BwE&dclid=CLyZ_KSwl9wCFaijswod4zcJLw
Unless, that is, your electric power is coming solely from a nuclear power plant or solar or wind power. (I am a little weird in that I don't count hydro -- the environmental damage from the dams is too great).
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
The unit they are looking at above is rated at Recovery Rate at 90F Rise (gallons/hour) - 98.
But will it do the job?
Albert Einstein
What is the cost of gas per therm, and the cost of electricity per kwh?
"Reducing our country's energy consumption, one system at a time"
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Baltimore, MD (USA) and consulting anywhere.
https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
Albert Einstein
In June we used 961kwh for a total cost of $124.15. The actual electricity only cost $74.76, the rest is taxes and BGE delivery charges but they are based on how many kWh used except for $8.26 in fixed customer charges. So the variable cost was $115.89 for 961kWh. Current electric cost is 7.642 cents per kWh and will increase to 7.810 cents per kWh in October.
During the same period we used 28 therms of gas for a total of $40.84. The actual gas use charge was only $12.08. The rest is usage based delivery fees and taxes except for $15.00 fixed customer charges. So the variable cost was $25.84 for 28 therms. In January we used 516 therms most of which is for heat. An indirect would not make sense with the size of the boiler.
We use gas for cooking and a gas dryer as well as DHW.
The behemoth boiler is gas, but I shut off the pilot in the off season.
I may just need to crank up the tstat a bit and insulate the pipes.
@Steamhead
Frank, you and Gordo are the best. You are true craftsmen and I suggest anyone with an old system like mine in the Maryland region should seek your counsel ether or not they think it necessary. Do you know how BGE addresses the potential need for a larger meter?
"Reducing our country's energy consumption, one system at a time"
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Baltimore, MD (USA) and consulting anywhere.
https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
Understood. Thanks
Compared to what I sell in a store of water heaters, your old one is really giant
Yours, Larry
Yours, Larry
> Hi and good! I’ve gotten over fifty years from tanks where the anode was replaced regularly.
>
> Yours, Larry
How old are you?!?
Yours, Larry