Water Heater Question - InspectionNews

fritzkelly · #1 (**permalink**) 01-03-2008, 09:04 PM

In the intrest of lower utility bills. I have decided to replace my propane water heater with electric. I plan to run it when the electric rates are cheaper at night and in the morning. Since it won't be on all the time, I decided to go for an 80 gallon, figuring it would hold the hot water we needed in the daytime and could stay off.
80 gallon water heaters are fairly expensive ($600?) but I found a plumbing supply house that had some new (unused) 1996 units for $250, still with a 5 year warranty from purchase. As I understand it, electric water heaters are basically 100% efficient, but the insulation may be lower than a new unit. Would I be making a mistake purchasing one of these?

Jim Luttrall · #2 (**permalink**) 01-03-2008, 09:20 PM

Fritz, I doubt there is much difference in insulation levels between a '96 and a '08 unit of the same caliber, you should be able to get specs from the man and compare.
Have you really compared the energy dollars between electric an propane. Your area may be different, but it would surprise me greatly to find electric costs cheaper than propane even allowing for cheaper night time rates and greater standby losses with a gas fired unit.
Have you thought about tank-less?

Rick Hurst · #3 (**permalink**) 01-03-2008, 09:24 PM

A gas water heater is usually going to save money than an electric water heater.

Bigger is not always better.

If you don't have a really large family you might try a tankless instead.

Personally, I would not buy any equipment of that age that has just been sitting around in a warehouse but that my opinion.

A newer unit is going to be better insulated which save costs.

rick

fritzkelly · #4 (**permalink**) 01-03-2008, 09:30 PM

Thanks Jim and Rick, I did notice that this is insulated with fiberglass rather than foam. Propane here is over $3 a galllon and going up, I figure I spend $900 per year to heat water. My nightime elec rate is about 5 cents/ kwh. IF I can avoid the high rate hours, I will save alot.
I have looked into the tankless and do not think they save much, I may be wrong on that. Also, the old Bosch tankless I had (years ago)wouldnt produce hot water without the hot tap wide open, they have probably corrected that.
This is a great area for solar, unfortunately I do not have a good southern exposure.

Jon Randolph · #5 (**permalink**) 01-03-2008, 09:33 PM

How does the power company differentiate day time use from night time use? Around here the meter spins and is read once a month then you receive a bill based on that amount.

fritzkelly · #6 (**permalink**) 01-03-2008, 09:52 PM

Here, the classic spinning meter is being replaced with a digital meter that can tell the power use at any time of day along with alot of other things, (whether you are growing pot, etc.

).
They have come up with several different rate plans to choose from, some add a surcharge for higher peak demand, some run 9am to 9 pm, some from 7am to noon. It is all designed to confuse the consumer and make more money without technically raising rates (something that would have to be approved by the Corporation Commission).
What it boils down to is that the electric company has followed the lead of the phone company. If the consumer can't figure out the bill or billing system, they can't bitch about it. You especially can't bitch when you PICKED that rate plan.

Donald Merritt · #7 (**permalink**) 01-03-2008, 10:55 PM

If you want to save money on hot water, set the water heater to 115 degrees F. Gas water heaters are generally set at 125 degrees F. I have set mine to 115 degrees F.12 years ago and have never noticed the difference. Electric water heater come set from the factory at 135 degrees F. You can also set electric water heaters to lower temperatures but they have a slow recovery rate. Gas water heaters when set for 115 degrees F. will start the burner when the tank has lost about 5 gallons of water and due to the burner size will heat the incoming water much faster.

Don Merritt

Rick Hurst · #8 (**permalink**) 01-03-2008, 10:58 PM

Thats corporate America for you at its finest.

Rick Hurst · #9 (**permalink**) 01-03-2008, 11:10 PM

Has anyone seen this video regarding heat recovery from waste water?

An Inconvenient Truth --- About Water Heating

Michael Thomas · #10 (**permalink**) 01-04-2008, 06:40 AM

The larger NG and propane tankless units can supply an entire house, BTW. We have a Takagi T-M1, and it can run a bath, a shower, the DW and a bathroom and kitchen sink at the same time, pretty nice if you have house guests taking 6 showers in a row.

Jerry Peck · #11 (**permalink**) 01-04-2008, 06:52 AM

Quote:

Originally Posted by Rick Hurst

Has anyone seen this video regarding heat recovery from waste water?

An Inconvenient Truth --- About Water Heating

Very interesting idea.

Would not work well, though, on homes without a basement as there would not be any vertical section, and the water in horizontal sections runs along the bottom.

Still, quite ingenious.

Nolan Kienitz · #12 (**permalink**) 01-04-2008, 10:39 AM

Some additional "food for thought" with respect to Tankless systems.

#13 (**permalink**) 01-04-2008, 02:31 PM

Quote:

Originally Posted by Fritz Kelly

In the intrest of lower utility bills. I have decided to replace my propane water heater with electric. I plan to run it when the electric rates are cheaper at night and in the morning. Since it won't be on all the time, I decided to go for an 80 gallon, figuring it would hold the hot water we needed in the daytime and could stay off.
80 gallon water heaters are fairly expensive ($600?) but I found a plumbing supply house that had some new (unused) 1996 units for $250, still with a 5 year warranty from purchase. As I understand it, electric water heaters are basically 100% efficient, but the insulation may be lower than a new unit. Would I be making a mistake purchasing one of these?

The idea that electric heat is 100% efficient is deceptive. In the case of electricity, unlike gas of one kind or another, the losses are in the distribution system. I'm not going to change my 96% AFUE, 98.7% SSE gas furnace for a 100% electric resistance heater in my cold climate. I hope that's not an engineering recommendation, of course.

Ken Amelin · #14 (**permalink**) 01-04-2008, 04:17 PM

Fritz,

The answer is simple math.

at the rates you quoted: Propane = $3.00/gal & 1 KWH = $.05 then electricity @100% eff = 68,260 btu/$1.00
Propane @ 85% eff = 25,953 btu/$1.00

Additional things you need to take into consideratrion are first cost, replacement cost, cost of capital, and maintenance. Without doing the life cycle cost analysis, My take is propane is cheeper than electric.

Scott Patterson · #15 (**permalink**) 01-04-2008, 05:37 PM

You need to check on the cost of electricity in your area. In my area we have TVA power and at 6.8 cents per KWH we have fairly cheap power. When I lived in MS our electric was 13.9 cents per KWH!

Ken Amelin · #16 (**permalink**) 01-05-2008, 05:18 AM

Quote:

at the rates you quoted: Propane = $3.00/gal & 1 KWH = $.05 then electricity @100% eff = 68,260 btu/$1.00
Propane @ 85% eff = 25,953 btu/$1.00

Additional things you need to take into consideratrion are first cost, replacement cost, cost of capital, and maintenance. Without doing the life cycle cost analysis, My take is propane is cheeper than electric.

Looks like I can't do the math.
I meant to say electric was cheaper than propane.