Hot water heater question

texas_train wrote:

downtheroad wrote:
I have learned that not much about RVing is about saving money.

Heck, We paid a ton for these rigs and a ton more for something to pull them. If we wanted to rough it and save money I'd go back to tent camping and not have to think about a water heater.

We relax. We leave ours on all the time when we are camping and don't even think about the extra pennies.

He he I'd have to go one beyond that! We leave our electric water heater switch on most all time when connected to shore power and prior to showers turn gas option on in addition this recovers the 6 gal tank in about 10 minutes between showers also allows me to keep the thermostat such as hot doesn't cause 3rd degree burns if turned on first! (Yes there is a way to adjust that!!)

Curious on the 'adjust'.

Have an Atwood with optional adjustable t-stat?
Water heater t-stats are pre-set snap disc contact t-stats (Suburban & Atwood) except Atwood has an optional adjustable t-stat that replaces Normal temp t-stat (110*F to 150*F vs standard 140*F)

AN adjustable residential t-stat can be used if Suburban and a gas only water heater....but you state 'electric' and all available options.

Suburban use to offer an optional 120*F t-stat but don't find those anymore.

So curious about 'adjustable' :H

downtheroad wrote:
I have learned that not much about RVing is about saving money.

Heck, We paid a ton for these rigs and a ton more for something to pull them. If we wanted to rough it and save money I'd go back to tent camping and not have to think about a water heater.

We relax. We leave ours on all the time when we are camping and don't even think about the extra pennies.

He he I'd have to go one beyond that! We leave our electric water heater switch on most all time when connected to shore power and prior to showers turn gas option on in addition this recovers the 6 gal tank in about 10 minutes between showers also allows me to keep the thermostat such as hot doesn't cause 3rd degree burns if turned on first! (Yes there is a way to adjust that!!)

Sport45 wrote:

ZOSO wrote:

Sport45 wrote:

ZOSO wrote:

Sport45 wrote:

csamayfield55 wrote:
I don't have any exact numbers here but from someone who works around commercial AC and heating systems here is my thoughts. You can either take it or leave it.

It takes WAY more BTU's (British thermal unit's) to heat water from ambient temperature to say 120 deg. than it does to maintain that temperature for a period of time. The water heater may cycle 4 or 5 times a day for short periods but it is not nearly as much heat energy than letting it cool and then reheat even 2 times a day.

Same for your AC unit's. If you let your rig heat soak till it is too hot to bear inside then turn on your AC it will take much more energy to remove that heat than if you set your stat at a comfortable level and maintain that level.

Chris

Sounds good on the surface, but I ain't buying it.

The heat loss from the hot water tank is to the atmosphere through the insulation on the tank. Heat loss is a function of the temperature difference so the colder the water is the less btu's per hour are being lost. Keeping it hot 24 hrs/day means you are radiating the most heat to the atmosphere and that has to be replenished with propane or electricity. Allowing it to cool between uses radiates less heat and uses less energy in the long run. (Even if it seems like it's firing longer).

Well, I'm going to agree to disagree with you on this Sport45. I'm definitely buying what Chris is selling!

As you wish.

But unlike speed limits, it's hard to break the laws of thermodynamics. :)

One would have to know how much heat is radiated to the atmosphere with the heater firing however many time a day, to maintain temperature VS. how much heat is radiated to the atmosphere with the heater firing however many times a day to heat water from air temperature to usable hot temperature. Obviously the heat source would run longer to take water up from air temperature.

Throw in all the variables and personal use habits...Well, it's not just as simple as a science lab law. A control experiment doesn't really indicate how things would pan out on a personal use level.

I wonder if anyone flips there HW heater on and off in their house?

As it's been mentioned before we're not talking gobs of money so I'll agree to disagree. It's not worth the effort to explain the science.

And no, I don't turn off the water heater in my house. I'm happy to pay the extra to have hot water on demand. I just wish the builder hadn't put the thing in the attic and run the line three times around the house before feeding the master bath... It's a long wait for hot water where we would really like it the quickest.

Get a recirculating pump and use it during the day or other certain times.

jalichty wrote:
I generally shut the hot water off when we leave the trailer in the morning to go fishing or sightseeing and then turn it back on when we get back so we'll have hot water to do dishes, etc. I then shut it off when we go to bed as I don't feel hot water serves a purpose when we are sleeping. It's not a matter of saving money, I just turn it off when it's not needed. We did a 3,800 trip last spring, always in campgrounds with electricity but never used the electric side of the water heater, just used the propane as I didn't really need the faster recovery time of using electric and gas at the same time. As said above, if you have to worry about the cost of propane versus electricity, you might be a bit over your pocketbook.

I don't worry about every penny for sure! But when the power is FREE and propane costs me money and time filling it up I will use the FREE power for my WH.

Sport45 wrote:

ZOSO wrote:

Sport45 wrote:

ZOSO wrote:

Sport45 wrote:

csamayfield55 wrote:
I don't have any exact numbers here but from someone who works around commercial AC and heating systems here is my thoughts. You can either take it or leave it.

It takes WAY more BTU's (British thermal unit's) to heat water from ambient temperature to say 120 deg. than it does to maintain that temperature for a period of time. The water heater may cycle 4 or 5 times a day for short periods but it is not nearly as much heat energy than letting it cool and then reheat even 2 times a day.

Same for your AC unit's. If you let your rig heat soak till it is too hot to bear inside then turn on your AC it will take much more energy to remove that heat than if you set your stat at a comfortable level and maintain that level.

Chris

Sounds good on the surface, but I ain't buying it.

The heat loss from the hot water tank is to the atmosphere through the insulation on the tank. Heat loss is a function of the temperature difference so the colder the water is the less btu's per hour are being lost. Keeping it hot 24 hrs/day means you are radiating the most heat to the atmosphere and that has to be replenished with propane or electricity. Allowing it to cool between uses radiates less heat and uses less energy in the long run. (Even if it seems like it's firing longer).

Well, I'm going to agree to disagree with you on this Sport45. I'm definitely buying what Chris is selling!

As you wish.

But unlike speed limits, it's hard to break the laws of thermodynamics. :)

One would have to know how much heat is radiated to the atmosphere with the heater firing however many time a day, to maintain temperature VS. how much heat is radiated to the atmosphere with the heater firing however many times a day to heat water from air temperature to usable hot temperature. Obviously the heat source would run longer to take water up from air temperature.

Throw in all the variables and personal use habits...Well, it's not just as simple as a science lab law. A control experiment doesn't really indicate how things would pan out on a personal use level.

I wonder if anyone flips there HW heater on and off in their house?

As it's been mentioned before we're not talking gobs of money so I'll agree to disagree. It's not worth the effort to explain the science.

And no, I don't turn off the water heater in my house. I'm happy to pay the extra to have hot water on demand. I just wish the builder hadn't put the thing in the attic and run the line three times around the house before feeding the master bath... It's a long wait for hot water where we would really like it the quickest.

I'm in complete agreement with you there Sport45! Certainly not enough saving or loss to bother monitoring or worry about or flip the HW on and off ad nauseam. Unless that's an interest for a person, then they should do so.

You definitely don't need to take the time to explain any science to me. I follow the principles of thermodynamics. I'm saying in the real world, there are just too many variables to give a decisive, sweeping answer to the OP's question. Way too many variables. For my personal situation, I'll turn on the HW or heat or AC and leave it do it's job.

You are probably already aware, you can get a recirculating pump for your hot water issue at home. Last I checked them out, they were pretty hard on electricity. Could flip it on and off though.....:hHmmmmmm.....I wonder......Er nevermind.

Nice chatting with you about something neither one of us could really care less about Sport45 ;) All the best!

I generally shut the hot water off when we leave the trailer in the morning to go fishing or sightseeing and then turn it back on when we get back so we'll have hot water to do dishes, etc. I then shut it off when we go to bed as I don't feel hot water serves a purpose when we are sleeping. It's not a matter of saving money, I just turn it off when it's not needed. We did a 3,800 trip last spring, always in campgrounds with electricity but never used the electric side of the water heater, just used the propane as I didn't really need the faster recovery time of using electric and gas at the same time. As said above, if you have to worry about the cost of propane versus electricity, you might be a bit over your pocketbook.

If you are in a situation where you really have to worry about the cost of operating the hot water heater, you are already in way over your head.

We adhere to the KISS principle (keep it simple, stupid!). When I set up and have the shore water supply connected, I flip the electric water heater switch to the "on" position. When we're getting ready to leave, part of my routine is to ask Sandy if she's through with the hot water and holding tanks as I'm heading outside to tear down. If I get a "yes", then I flip the electric water heater switch to the "off" position. At my advanced age and with old timer's disease setting in, that's about all the complexity I care to handle. ;)

Rusty

ZOSO wrote:

Sport45 wrote:

ZOSO wrote:

Sport45 wrote:

csamayfield55 wrote:
I don't have any exact numbers here but from someone who works around commercial AC and heating systems here is my thoughts. You can either take it or leave it.

It takes WAY more BTU's (British thermal unit's) to heat water from ambient temperature to say 120 deg. than it does to maintain that temperature for a period of time. The water heater may cycle 4 or 5 times a day for short periods but it is not nearly as much heat energy than letting it cool and then reheat even 2 times a day.

Same for your AC unit's. If you let your rig heat soak till it is too hot to bear inside then turn on your AC it will take much more energy to remove that heat than if you set your stat at a comfortable level and maintain that level.

Chris

Sounds good on the surface, but I ain't buying it.

The heat loss from the hot water tank is to the atmosphere through the insulation on the tank. Heat loss is a function of the temperature difference so the colder the water is the less btu's per hour are being lost. Keeping it hot 24 hrs/day means you are radiating the most heat to the atmosphere and that has to be replenished with propane or electricity. Allowing it to cool between uses radiates less heat and uses less energy in the long run. (Even if it seems like it's firing longer).

Well, I'm going to agree to disagree with you on this Sport45. I'm definitely buying what Chris is selling!

As you wish.

But unlike speed limits, it's hard to break the laws of thermodynamics. :)

One would have to know how much heat is radiated to the atmosphere with the heater firing however many time a day, to maintain temperature VS. how much heat is radiated to the atmosphere with the heater firing however many times a day to heat water from air temperature to usable hot temperature. Obviously the heat source would run longer to take water up from air temperature.

Throw in all the variables and personal use habits...Well, it's not just as simple as a science lab law. A control experiment doesn't really indicate how things would pan out on a personal use level.

I wonder if anyone flips there HW heater on and off in their house?

As it's been mentioned before we're not talking gobs of money so I'll agree to disagree. It's not worth the effort to explain the science.

And no, I don't turn off the water heater in my house. I'm happy to pay the extra to have hot water on demand. I just wish the builder hadn't put the thing in the attic and run the line three times around the house before feeding the master bath... It's a long wait for hot water where we would really like it the quickest.

bpounds wrote:

ckwizard777 wrote:
Why are y'all even worrying about this.
Turn it on and forget about it.

We're taking a break from arguing over tires and hitches. Hey, we gotta argue over something. :)

What are you talking about? :B