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  • #16
    Re: water heater heat loss

    My natural gas company charges $10.28 cents a month for what I call an existence fee. If you have service and do not use 1 therm, btu, whatever-you get charged $10.28 just to have the service on. If you use $10.00 worth of gas, your bill is $20.28. Also, only .28 is an excise tax. The other $10.00 is for nothing but "service privelege."

    Is it this way everywhere?

    J.C.

    Comment


    • #17
      Re: water heater heat loss

      Originally posted by JCsPlumbing View Post
      My natural gas company charges $10.28 cents a month for what I call an existence fee. If you have service and do not use 1 therm, btu, whatever-you get charged $10.28 just to have the service on. If you use $10.00 worth of gas, your bill is $20.28. Also, only .28 is an excise tax. The other $10.00 is for nothing but "service privelege."

      Is it this way everywhere?

      J.C.
      Here it is.

      Comment


      • #18
        Re: water heater heat loss

        I just checked the brochure on my Phase III tank. Just under 1 degree per hour standby heat loss.

        I haven't found standby loss numbers listed anywhere for a natural draft heater yet....still looking

        Comment


        • #19
          Re: water heater heat loss

          Bring me some Advil...

          With a required minimum of 15 BTU/sq foot of tank surface area...

          6.2832 sq feet for top & bttom on a 24" diamter tank

          10.9935 sq feet for the side of that tank at 42" high (3.5') (figured minus burner height)

          At approximately 17 sq feet of surface area & 5.49675 for an inside diameter of 6" for the flue, lets call it 23 even for simplicity.

          Thats a total of 345 BTU per hour with 1 BTU being a degree per pound of water, a 40 gal tank takes 333.2 BTU to heat one degree.

          The actual dimensions are NOT what I posted, just roughing it, but one degree per hour sounds right.

          Comment


          • #20
            Re: water heater heat loss

            ready for real life example #2

            last week joey and i went camping from wednesday 8 am to sunday 3pm.

            before we left, i shut off my 20 year old 40 gallon gas heater. actually i turned the cold off and turned the thermostat to pilot.

            come home sunday and as soon as i get in, i go outside to turn on the heater. joey didn't realize this and started a load of her laundry.
            i walk in and tell joey that the water is not hot since i just turned it on

            then i grab the hot fill hose and it's actually hot

            so, with only a pilot running on my 20 year old 40 gallon water heater, the water remained hot enough to actually do a proper load of laundry.

            true story from last week.
            i was at the plumbing supply house and tagagi had a counter day. the sales rep was excited to see me and offered to fill up my large truck with his tankless heaters

            after i explained to him that i was the last guy he could sell a tankless to, we had a nice 20 minute conversation.

            hate to say i was right, but he agreed with me 100% and said that unfortunately plumbers are installing not only his product wrong, but selling tankless to people that will never benefit from it's use.

            prime example i explained to him was the newer high efficiency washers that cycle on the fill cycle. the heater will turn itself on and off and never truly have 100% hot water. he said that is a complaint that they are aware of. to overcome it you need to install a "buffer tank" with a circ pump. basically a 5-10 gallon tank that will act as your buffer to mix the hot and cold water produced when a tankless shuts off. or just an electric 5-10 gallon tank that doesn't circ but maintains the little stored water. same issue with a shower when 1 person showers and the next follows up a minute later. the water in the pipes is hot, but be prepared for that 6 second cold slug that will be coming before the heater re-fires.

            told you there was more to this story.

            rick.
            phoebe it is

            Comment


            • #21
              Re: water heater heat loss

              That's it

              I'm nominating this for Thread of the Week

              Not because of Rick's and Joey's epiphany doing laundry but because Duck did the math in long form

              I haven't checked his numbers but looks right to me

              Think about it...that's 1 degree per hour...every hour of every day/week/month /year over the life of a heater.

              What's that add up to? ...Duck?

              Comment


              • #22
                Re: water heater heat loss

                Originally posted by plumberscrack View Post
                That's it

                I'm nominating this for Thread of the Week

                Not because of Rick's and Joey's epiphany doing laundry but because Duck did the math in long form

                I haven't checked his numbers but looks right to me

                Think about it...that's 1 degree per hour...every hour of every day/week/month /year over the life of a heater.

                What's that add up to? ...Duck?
                Gee, thanks...buddy.

                Figured you might help out by breaking out the calculator there yer self for all my effort!

                FINE THEN!

                One Therm in my area = $1.80

                One Therm is 100,000 BTU's

                Fifty gallons of water weighs 416.5 lbs.

                Thats a BTU loss of 416.5 BTU's per hour.
                9996 BTU per day
                299880 BTU per month (30 day)

                Rounded up thats 3 therms per month...$5.40 (edited...I goofed and called it 1/3rd therm before)

                THIS is NOT what saves money on tankless.
                See Spode's "real life" savings of $40 a month, he obviously needs to kick the kids out...they shower too much!
                It's also a STRONG argument AGAINST electric tankless's.

                Rick is determined to "reveal the myth" of tankless...the factor that's being overlooked is the obvious.

                BTU per BTU...tankless BURNS more efficiently, about 1/3rd more bang for the buck.

                Which brings us to the ACTUAL point, number of bucks you spend per capita.

                For someone who spends $20 for hot water, it's stupid to invest in one.
                For someone that spends $80, it's stupid not to consider, if you can afford the intitial cost...especially in my state where the gas co offers a $300 rebate.

                After the initial installation, the cost of replacement goes down substantially, I'd say at least $1000 less with not having to repipe the gas, water and drill through the foundation for a new vent.
                Last edited by DuckButter; 08-24-2008, 06:22 PM.

                Comment


                • #23
                  Re: water heater heat loss

                  Rick, you've had a tankless sitting for awhile. Would you please tee up the gas and water lines and run one for a month, then the other or whatever to give better information on this. You might find yourself to be wrong and that's ok. You might also find yourself to be right which I'm sure is even more ok.

                  Hook'em up, run your lives just as you normally would and post likes/dislikes. Savings or no savings. I can do the math, (sometimes ) but math isn't always perfect and an X factor can be left out.

                  J.C.

                  Comment


                  • #24
                    Re: water heater heat loss

                    In my area, in many cases a retrofit tankless heater, Cat III flue through the roof, and new gas line will run you considerably more then $3K. There's also the inconvenience. Replacing a leaking conventional water heater with a new conventional heater can be done the same day as the call came in. Putting in a tankless heater generally requires a sight visit before an estimate can be created. Then, the quote has to be accepted. At which point, a permit has to be pulled and an inspection arranged. On top of that, the actual process of installing a tankless heater can take a couple of days. All the while, the HO has no hot water.
                    That said, I can't wait until the condensing tankless heaters become standard. 95+%, woo, woo!

                    As for electric tankless, there are cases where it is attractive. For example, I've got a customer who makes significant photo voltaic electricity. He's trying to minimize his gas usage and use his home made electricity where ever and when ever possible. If it's a gas appliance, it's on the endangered list. That goes for water and space heaters.

                    Comment


                    • #25
                      Re: water heater heat loss

                      Ironically, I'm peeking at the Navien site as we speak.

                      Comment


                      • #26
                        Re: water heater heat loss

                        Originally posted by JCsPlumbing View Post
                        Rick, you've had a tankless sitting for awhile. Would you please tee up the gas and water lines and run one for a month, then the other or whatever to give better information on this. You might find yourself to be wrong and that's ok. You might also find yourself to be right which I'm sure is even more ok.

                        Hook'em up, run your lives just as you normally would and post likes/dislikes. Savings or no savings. I can do the math, (sometimes ) but math isn't always perfect and an X factor can be left out.

                        J.C.
                        j.c. you've got a good memory

                        at a $15.00 a month total cost with taxes gas bill. there is no reason to go through all the expenses of installing my heater.

                        i can already tell you that my hi efficiency washing machine will not properly operate with hot water. if i set it on hot, then i will get warm water. it's pretty much impossible to get full hot water from this unless i install a blending tank. not only what i've stated, but the factory rep from tagagi too. not to mention the 6 second delay factor in getting hot water.

                        i initially purchased this heater to test it at my house, but joey is not letting me even think about it as i've already mentioned the work involved to run the gas and water so i don't have to vent it through my tile roof.
                        plus are you trying to give my 20 year old 40 gallon heater a heart attack.

                        i'll have an easier time installing that bidet seat that's been sitting since december

                        i have a week before she gets home

                        thanks

                        rick.
                        phoebe it is

                        Comment


                        • #27
                          Re: water heater heat loss

                          You should install both before she gets back and be passed out with empty costco boxes around you when she walks in.

                          J.C.

                          Comment


                          • #28
                            Re: water heater heat loss

                            Originally posted by Plumbus View Post
                            In my area, in many cases a retrofit tankless heater, Cat III flue through the roof, and new gas line will run you considerably more then $3K. There's also the inconvenience. Replacing a leaking conventional water heater with a new conventional heater can be done the same day as the call came in. Putting in a tankless heater generally requires a sight visit before an estimate can be created. Then, the quote has to be accepted. At which point, a permit has to be pulled and an inspection arranged. On top of that, the actual process of installing a tankless heater can take a couple of days. All the while, the HO has no hot water.
                            That said, I can't wait until the condensing tankless heaters become standard. 95+%, woo, woo!

                            As for electric tankless, there are cases where it is attractive. For example, I've got a customer who makes significant photo voltaic electricity. He's trying to minimize his gas usage and use his home made electricity where ever and when ever possible. If it's a gas appliance, it's on the endangered list. That goes for water and space heaters.
                            A point to mention, with many jurisdictions requiring flue liners to continue using natural venting, powervented heaters are gaining momentum.
                            A large percentage of the water heaters I do now are powervented, we don't generally run the vent to the roof, but rather through the nearest foundation wall.

                            Comment


                            • #29
                              Re: water heater heat loss

                              It's true, they either retain heat or burn a lot of BTU's with that pilot! Had one at a cottage out here, they left for the week, put it on pilot, came back and it was up to temp. I had a hard time with it too.

                              I was told by one of the factory trainers that an electric heater will drop 25 degrees in 30 hours in a 70 degree room. (40 gallon) I guess there's enough info there to figure the BTU's if you really wanted to.
                              sigpic3:00, I mean 5:00, and work is done. Time to crack a cold one.

                              Comment


                              • #30
                                Re: water heater heat loss

                                i also have been installing more pvent tanks lately--also i have installed about 50 % more tankless this year than last--i use the best--rinnai----its gotta be-rush backs it!!!!!--tagagi is not popular out here--is this the go to 4 you guys???--if u have an issue with rinnai and call, someone always answers and they speak english--guaranteed--isnt that nice--and they have 12 year warranty now(the best) and are quick to come out for help or warranty--i have good luck with rinnai

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