I this plan worth it?

I got a pretty high electric bill that I am afraid is going to get higher. Being a farmer it is that time of year when I must plug in all the stock tank heaters for the sheep, chickens, ducks, etc to keep them all in fresh, drinkable water. There are other electrical loads as well, but I have an electric hot water heater that is sucking up a fair chunk of juice.

Until I can get a boiler mate for my Propane Boiler...a $900 appliance, I sit patiently as I watch a tub of water on my hand fed coal/wood stove merrily boil water away. (I keep it there just to give the air inside our home some moisture).

I was thinking if I built a pre-heater for my hot water heater, it would take some of the edge off the electric hot water heater. The plan is pretty simply, tap into the tub on top of the coal stove, then run lines from the tub to a tank next to my water heater. I would then run a coil of pex into the tub of water that is being heated from my coal stove about 30 feet away, and connect the pex from my incoming water line, through the tub of hot water, and then into my hot water tank. I got just about everything to do this, including the fittings, pipe and even the circulator so cost is not really an issue, my question is...

Will it make a big difference on my electric bill?

Don't know what your paying for electric out there, but in MA, ANYTHING you do that's NOT run by electric is going to be MUCH cheaper.

Measure how much water is in the tub in gallons. Then take its temperature when cold and time how long it takes to reach various temps. This should give you some idea whether or not it is practical or worthwhile. If it takes an hour to reach 150 and there is 10 gallons then you have a starting point. 10 gallons per hour less piping losses.

My bill this week said about 14 cents per kw. That is with the delivery charge, and with the actual usage as we get two separate bills here.

NoSmoke wrote:Until I can get a boiler mate for my Propane Boiler..

Be careful with the boiler mate idea. I have an oil-fired cold-start boiler, with an indirect SuperStor tank which I think is like Boiler Mate. Standby heat loss in the boiler and piping makes the oil system more expensive than electric during the months when my boiler is used only for domestic hot water (which is essentially every month since most of my heat comes from coal.) I shut off my oil burner and installed an electric water heater this summer, and careful measurement indicates it will pay for itself ($500) in less than 2 years.

If your propane boiler is hot anyway, because it is providing heat for the house, then the electric option probably won't save anything in those months. Mine is set up so I can switch between oil and electric or both. Right now I am running both in parallel just because I want to know that the oil burner is successfully firing a couple times a day, since it is my backup in case I have to shut down the coal.

Thanks Bob for the warning...

I have been thinking about this for a few weeks now, but what made me post this yesterday was the guy that delivers my propane came and filled up my propane tank (300 gallons...ouch) and was telling me he replaced his electric hot water heater with an on-demand propane system and it saved him $35 dollars per month on his electric bill. I have been slowly replacing a few of my electric appliances with propane ones like I have a gas dryer now and a gas range, so the electric hot water heater is on my list for replacement as well. December and January is my biggest electrical demand I know, but boy that bill stings when you are unemployed.

I can sign up for a Farm Energy Audit since I am a farm here, but my sheep farm is not really big enough to justify it. They were really designed for large dairy farms and Maple Sugar Operations, not sheep farmers who by comparison use very little energy. The energy audit is about $300 dollars in out of pocket expenses so while it is not expensive, it is 1/3 of a boiler mate, and at $35 per month in savings may take a wee bit of time to pay back. That is why I look at my boiling pot of water on the stove steam away nicely and wonder if it cannot be pumped to the right spot and be put to use.

I just fired my stove a few minutes ago so I am watching the temperature climb in the water bucket and so my feasibility study is under way.

What is your current propane cost per gallon?

$2.34 per gallon.

The guy was telling me that it is based on tank capacity and fuel usage per year, but that there is 19 different price ranges for propane at his company!

Rob R. wrote:What is your current propane cost per gallon?

NoSmoke wrote:$2.34 per gallon.

The guy was telling me that it is based on tank capacity and fuel usage per year, but that there is 19 different price ranges for propane at his company!

do you own your tank or lease it from that propane company? is there a number of propane companies in your area to shop price?

Well it took 20 minutes to raise 3 gallons of water to 120 degrees, the same temperature my hot water heater is set at. I don't believe thermal dynamics is linear, but assuming that it is, that would mean I could heat 9 gallons of water to 120 degrees every hour. Throwing in some losses, I could heat up 40 gallons (the same as my electric hot water heater) in 5 hours time. The recovery time of my electric hot water heater is about 31 gallons in a hours time.

About the only time we use a lot of hot water is in the morning. I take a shower and so does the wife, and typically she takes a very long one and runs out of hot water by the end of her shower. That works well because I typically start the stove at 04:30 and she takes her shower at 08:00 so a significant amount of water would be pre-heated by the time she got ready to soak her bones.

I do plan on upgrading the pot of water on the stove to a 10 gallon pot, but no other changes are in order.

What says the smart people...is it worth it?

titleist1 wrote:Do you own your tank or lease it from that propane company? Is there a number of propane companies in your area to shop price?

I lease it and other propane companies; while existent, will not fill another customers tank. In fact here, they even tag the fill tanks of people who use oil and will not fill tanks belonging to other customers.

We discussed the leased/buy option of the tank with my brother-in-law who is not affiliated whatsoever with the propane company I use, he is merely a teacher for the Maine Oil Dealers at their HVAC School, and he said to lease the tank due to the testing requirements of propane tanks. It seemed like a good idea to me, and while I know it limits my ability to shop for propane, running low on propane and not having anyone willing to fill it due to the tank being out of testing date did not sound like a few pennies per gallon in savings would be worth the hassle. I am not saying I made the right decision, just stating how I arrived at my decision.

I think one of the reasons why my propane costs more is due to the amount of consumption I have. I do save some money by having a big 500 gallon tank, but I just don't burn much propane. The tank sized was based on my Propane Boiler, a Reniai Heater and all my other appliances, but a clothes dryer and range really do not consume much fuel, and with a wood/coal stove in the house now (installed after the tank was selected), I just don't burn much propane. Maybe 300 gallons a year...which is not bad for the size of this house.

I did flip on my boiler the other day, the only reason being is that I have radiant floor heat in half my house. This is in the bedrooms which is a ways from my stove. When my stove is running the temp in the back bedrooms is about 75 degrees, and 95 in the kitchen, but since it is so hot, I only run the stove in the morning. My house is so tight that it will stay warm all day and well into the night. Most mornings it is still 70 in the kitchen with no fire in the stove for 16 hours, BUT the bedrooms drop to 63 degrees or so. Just for fun, and to take the temperature swings out of the bedrooms, I have been running my boiler to keep the rooms warm, with a set temperature of 70 degrees. The boiler only runs from about 00:01 to 06:00. For now I think I can afford the propane considering how evenly heated the house is. Those temperature swings sucked!

BUT I am in the process of redoing my whole house so that all of it will have radiant heat. When that occurs I will install a boiler in my mudroom and just use it to heat water, pumping it into my propane system which is designed to handle a secondary boiler. In a perfect world I would have already done this, but I am on lay-off. I am not whining, I have enough money to pay all my bills every month because I am pretty much debt free and very frugal, BUT I just don't have any extra money to retro-fit my home. When I get back to work however, I can buy more pex and have radiant heat throughout.

NoSmoke wrote: It seemed like a good idea to me, and while I know it limits my ability to shop for propane, running low on propane and not having anyone willing to fill it due to the tank being out of testing date did not sound like a few pennies per gallon in savings would be worth the hassle. I am not saying I made the right decision, just stating how I arrived at my decision.

I think one of the reasons why my propane costs more is due to the amount of consumption I have. I do save some money by having a big 500 gallon tank, but I just don't burn much propane. The tank sized was based on my Propane Boiler, a Reniai Heater and all my other appliances, but a clothes dryer and range really do not consume much fuel, and with a wood/coal stove in the house now (installed after the tank was selected), I just don't burn much propane. Maybe 300 gallons a year...which is not bad for the size of this house.

your area may be different, but the savings by owning our tank is significant, more than a few pennies per gal. we burn about the same gals / year as you, about 300 - 350. we have a 1000 gal tank so it is about every two years that i get it filled. the last fill up a few weeks back was $1.7something cant remember exactly, the price for a leased tank per gallon was around 33% higher.

I know the leased tank price because at the same time i also shopped the price for our church tanks which are owned and i always ask the leased price vs owned tank price so i can provide ROI numbers to the finance committee. the church price was $1.59 i think ($1.5something anyway) because of the higher usage. this was the least amount saved per gal since we bought the tanks, we have saved up to $1.50 per gal when prices were higher a few years ago.

the propane companies are the same down here, won't fill another companies leased tanks and you need to show the receipt of the tanks you bought to prove ownership. I only had one company so far that wanted to do a tank test before even giving me a price over the phone, they wanted to schedule that about 3 weeks out. i passed on this "offer" and just went on to the next company. maybe that will be the next trend to make them some "service" money.

NoSmoke wrote:The plan is pretty simply, tap into the tub on top of the coal stove, then run lines from the tub to a tank next to my water heater. I would then run a coil of pex into the tub of water that is being heated from my coal stove about 30 feet away, and connect the pex from my incoming water line, through the tub of hot water, and then into my hot water tank. I got just about everything to do this, including the fittings, pipe and even the circulator so cost is not really an issue, my question is...

What happens if something goes wrong and the stove and the pex melts?

Wow Rob, that is a significant difference.

The guy said a greenhouse in the same town as me gets the lowest price of $1.90 right now due to their usage of 8000 gallons per year. I thought this was unique because these people are super "greenies" and have mega-money and will do anything to be green, even if it costs them 10 times as much. To hear they go through so much propane was interesting just because I know them and their philosophy and expected more in the way of renewable fuels.

Thanks for the information on the leased/owned tanks. As I rely more and more on coal/wood, and when I become 100% radiant heat and heated via a wood/coal boiler, I will use less and less propane. As is, I had to send a 100 gallon tank back to the propane company that was used to heat my woodworking shop. When it required a fill up every two years, they countered by charging a yearly service for having it, and while the cost escapes me for that fee, it was high enough so I sent the tank back...yes paying a service charge fee for even doing that (because they had to come out and get it).

As for the Pex, I did not get into the finer details of my plan in the interest of brevity, but I know Pex would melt. I would have to run copper from the water canister on top of the stove down to the floor and then take it from insulated pex from there.

NoSmoke wrote:... the guy that delivers my propane came and filled up my propane tank (300 gallons...ouch) and was telling me he replaced his electric hot water heater with an on-demand propane system and it saved him $35 dollars per month on his electric bill

Makes sense that an on-demand tankless heater would save money but the payback period may be long because I think they are expensive to buy, and can be expensive to install depending on your venting options. When I said watch out for Boiler Mate, I was talking about the system where your boiler indirectly heats the water in an external storage tank. Getting AWAY from that, going to electric, was what saved me $35 per month. The issue is standby losses, that is, the heat lost while the system is NOT heating water. A tankless heater has very low standby losses because not much gets hot except the water you are using, right at the moment you are using it. A boiler heating water in an external storage tank has high standby losses because the boiler, and all the water it contains, and the pipes between boiler and storage tank -- ALL of them get hot. Then when the external tank is up to temperature, the boiler's burner shuts down and all that heat accumulated in boiler and pipes dissipates into the air, doing nobody any good. I can almost promise you that switching domestic hot water from electric to indirect-propane-heated will COST you $35 more per month, before even considering the high cost of the Boiler Mate tank, piping, pumps, controls, and all. Back when I bought my first house, and a gallon of oil or propane was 2 or 3 times the cost of a kilowatt-hour, the Boiler Mate system was good. With today's prices, oil and propane 20 to 30 times the cost of a KWH, it is not.