Electric vs. Propane

[HHFields]

I currently have a 2 year old Rheem Electric 40 Gallon Hot Water heater. I am considering changing to a 50 Gallon Power Vent Propane water heater, because of the following; After a 15-20 minute shower, and 10 minutes of no water water running, the next person to get a shower has about 5 minutes left of hot water. Also, my electric bill has been running $250-$400.00. After killing one breaker at a time and visibly watching the electric meter basically come to a halt when we shut off the hot water tank breaker, we have narrowed the energy sucking problem down to the hot water heater. Typical bill in this area with a setup like mine in around $80-$150.00. My only conclusion and I may be wrong, but we have a spring and our water is as cold as ice if not colder. We had a very cold December, and in January, I received the highest electric bill to date. Either way I decide to go, I believe I need to add a holding tank next to the hot water heater, so at least when the hot water heater needs water it is heating up room temperature water and not arctic water. I do not know if I am on the right track or way off the rails, but ANY input as far as my theory and what type of propane tank I should be looking at and if I go the direction of propane, how difficult would the setup be as far as venting would be greatly appreciated!

 

[Reach4]

Do you heat with propane? How much do you pay for propane?

How much do you pay for electricity. You can get close by dividing the total bill, taxes and all, by the number of KWH. You could subtract the fixed amounts from the total before dividing, but much of the add-ons are based on the usage.

Another factor, and it may be relatively small, is that a power vent WH will take electricity and propane.

 

[Sponsor]

 

[Stuff]

Doesn't sound right. Do you also have electric heat?

Note that a holding tank means that your furnace will be bringing the water up to room temperature. Not much but you still will have a bill.

What about a hybrid heat pump water heater?

 

[HHFields]

I have a heat pump and our emergency heat is propane. We spend $700.00/yr on propane. I am not familiar with the hybrid heat pump water heater.

 

[Jadnashua]

A holding tank may or may not help much...some of it would depend on its size and your pattern of use along with the normal temperature of the room it is installed in.

A typical electric WH has a max element size of around 4500W. On some, you can get both the top and bottom ones on at the same time, but normally, they switch and only one is on at a time. It's possible that you have a defective element that has not tripped the breaker, but if it were way out, you'd exceed the breaker capacity and trip it. In many places, the relative cost to make hot water runs from propane, oil, electricity, natural gas from expensive to less expensive. A burner verses an electric element will tend to have a faster recovery rate since the burner will be larger. 4.5Kwhr=15.3K BTU. Most burners on WH are at least 40K BTU, some a lot more. If you have really favorable electric rates, you might just want to go with a larger electric WH. You can call your supplier to get the typical BTU equivalent in a pound of propane (or get close online). That should help you figure out the efficiency and relative costs. Keep in mind that you put more BTU into a propane WH than those that actually heat the water (some goes up the flue), while with electric, it's basically 100% of the energy goes into making heat.

 

[WorthFlorida]

You can go to http://www.rheem.com/WHTechBulletins.aspx?Category=Residential Electric and find all kinds of information on how to check your water heater and recovery rates. Also, information on their hybrid systems.

You have two problems to address, lower the monthly cost and a continuous steady supply of heated water.

I think to hit on it and it is probably the very cold temperature of your cold water supply. Your usage is exceeding the recovery rate of the water heater heating elements. Even if you up it to 50 gallon electric, the recovery rate is the same. It all depends on the power input.

Sold in stores are 5500 watt elements. Check with your owners manual because many water heaters can be upgraded as long as long your AC wiring and breaker can handle to load. This will increase the recovery rate and upping to a 50 gallon electric may or may not be enough for your needs, however, it won't save any money on the electric bill.

So changing to a propane tank with usually a larger BTU input will be a big improvement, but as other stated, you'll need to find the cost.

Adding a storage tank will not help because the heat will come from the room and where does that heat come from? Warmer months, sure it is from the outdoors, but during heating season? Perhaps the best solution might be is to get the cold water supply preheated with a solar panel. Since you're in snow country a solar panel setup will need a heat exchanger because an antifreeze solution would be needed to be circulated. Big up front cost but it will solve two of your problems for a long time. Electric rates generally are more more stable as compared to propane. If rates suddenly rise because of the markets, your cost will go up immediately. With solar panels your cost will be almost the same.

Electric solar panels, that are coming down in price, could be used to power a water heater. Just another thought.

 

[Reach4]

After a 15-20 minute shower, and 10 minutes of no water water running, the next person to get a shower has about 5 minutes left of hot water

Look into a heat recovery system for the shower.
https://terrylove.com/forums/index.php?threads/add-tankless-natural-gas-to-existing-electric-tank-water-heater.65020/#post-482226 #4 is one good description.

For electric vs propane, it depends largely on relative fuel costs. In Ohio, you don't get government-subsidized electricity. You get government-taxed electricity. http://www.propane101.com/propanevselectricity.htm has some info, but they don't point out that propane is not 100% efficient. Propane prices vary with time and volumes. https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=W_EPLLPA_PRS_SOH_DPG&f=W . See https://terrylove.com/forums/index....-wait-for-new-improved-one.60794/#post-452306

 

[Stuff]

Expensive but here is an 80 gallon hybrid water heater. Supposedly uses 70% less electricity than conventional.
http://www.homedepot.com/p/Rheem-Pe...-and-10-Year-Warranty-XE80T10HD50U0/300620269

 

[Dana]

An electric water heater is a big load during the recovery period (ergo the meter stops spinning) but the duty cycle is low. It's unlikely (damn-near impossible) that the water heater is even as much half your power bill.

You can get more showering capacity out of any hot water heater by increasing the storage temperature, with a thermostatic mixing valve on the output to keep it at safe temperatures. The increased standby losses are are pretty small in dollar terms with an electric tank, since it has much better insulation than any propane fired water heater. A 2 year old electric has MUCH better insulation than a decade ago, and probably has another decade or more of service life left. Don't scrap it until you've really studied all the options.

How much do you pay per gallon for propane?

How much do you pay per kwh for electricity? (Take the whole bill, divide by the kwh to be sure that the fixed charges and delivery charges are reflected, not just the energy cost.)

If you have at least 5' of vertical drain down stream of the shower, you can also roughly double the capacity of the electric hot water heater with a drainwater heat exchanger (4" x 48" , or 3" x 60" or larger- fatter & taller is always better). These heat exchangers take heat you are literally sending down the shower drain and return it to the incoming potable water, pre-heating the icy-cold water to room temperature or slightly above before it enters the shower mixer & hot water heater. A DIY installation is usually pretty easy, and even a pro-install would be both cheaper and better than a propane power-vent.

It does nothing for tub-fills, since the drain has to be flowing at the same time the cold water is coming in for the heat exchange to take place.

 

[Victor Jimenez]

Interesting post Dana