[strider3700]

$this->bbcode_second_pass_quote('MonteQuest', '
')If you are talking about a gray box 6" X 8" with a round yellow dial inside, that is the one you want.

Hot water heaters are 220V. You need a heavy duty timer.

[MonteQuest]

$this->bbcode_second_pass_quote('strider3700', 'Y')ep thats the box. It's nowhere near girlfriend friendly enough for me to get away with it.

[MonteQuest]

My electrical subcontractor says a 7 day programmable might run $250.

The T-104 Intermatic I spoke of runs about $50.

Here's their website. See what you can find.

http://www.intermatic.com/

[MonteQuest]

Here's what I found for you:


$this->bbcode_second_pass_quote('', 'T')he WH40 and WH80 provides a convenient external override switch. Utilities in some areas of the country offer two electric rates for residential or commercial customers. One rate has the regular daytime electrical rate, the other is "off peak" rate. The off peak rate provides customers with lower-priced electricity during the nighttime and weekend periods. The special construction of the WH80, incorporating a skipper function, enables the customer to have all the hot water required, especially on weekends when the time switch permits 24 hour a day operation automatically. Since the WH80 has normally closed contacts, the water heater will remain ON during the weekend when the skipper is set to do so. Three sets of ON/OFF trippers (and three skipper screws for model WH80) are supplied.

[WebHubbleTelescope]

I don't understand why heaters need to get the water that hot. I have seen mention of trying to avoid Legionaire's Disease and other pathogens that like warm, but not hot, environments. When you end up taking a shower, the hot gets mixed with the cold so you end up instantly wasting all that energy anyways.

Then there is washing machine hot, but I only use warm, and the dishwasher, which would be ideal place for a small inline "tankless" heater. What else really requires hot water?

Heat losses follow the laws of thermal conductivity, which is proportional to the differences along a temperature gradient. Therefore keeping things only warm could end up saving lots of energy.

In the meantime, my own heater sprung a leak, so I have been taking cold showers. I really want to buck the conventional wisdom when I construct a new warm-water system.

[Frank]

Heat traps are a good idea, as is insulation. The simplest type of collector for you might be a batch heater which would preheat in summer (i.e. when you have sun) and you can draindown in the winter. Pretty simple: insulated box with cover (tempered glass works well), old 20-25 gal water heater with insulation stripped off and painted flat black. If you use an anti-siphon valve you won't even have to go up on the roof once it's installed.

If you're using electric baseboard and leaving the thermostats set at a steady temp, then progammable t-stats would pay for themselves pretty quickly. Home Depot has them and probably Canadian Tire and other stores.

[Tanada]

$this->bbcode_second_pass_quote('strider3700', 'O')k I'm now eyeing up my electric hotwater tank as being the next offensive in my on going war against the electric bill.

My plans for the following year include

move the tank - this is needed to gain space in it's current location not for efficiency

Build a inulated box around the tank - basically I'm thinking 3 inches of foam in a box around the tank(with an access door) I'll then stuff the rest of the space with loose pink insulation

add heat traps to the plumbing - I have to do the plumbing when moving the tank so might as well. Apparently they stop the hot water from circulating out into the pipes when water isn't running.

insulate all of the pipes - cheap, easy and I don't have much to do thanks to a fairly efficient layout.

add a timer to the heater- basically I want to turn it on in the mornings off dduring the day on in the evening off at night during weekdays. Then turn it back on all day during weekends

add solar heating - a nice project to build a collector and heat exchanger this winter, we'll see.

Now my question is about the timer. I've had a hell of a time finding any timer for hot water tanks, and the one I found was ultra industrial looking, definitely not what I had in mind. I was looking for something more like a programmable furnace thermostat. Can anyone point me to one?

I have a 220V programmable thermostat at home. Could one of those be used? I'm assuming the issue is the amperage the water tank draws is probably much higher then the thermostat can handle spliced directly in.

What about using a relay and a thermostat? 220V relays can't be that uncommon are they?

Any other suggestions?

[strider3700]

thanks for the links montequest. I'll see how much the other changes help before I decide to drop $250 on a timer.

tanada. I don't have any central heating system. I have electric baseboards(soon to be on a programmable t-stat) and a soon to be installed wood burner.

[Tanada]

$this->bbcode_second_pass_quote('strider3700', 't')hanks for the links montequest. I'll see how much the other changes help before I decide to drop $250 on a timer.

tanada. I don't have any central heating system. I have electric baseboards(soon to be on a programmable t-stat) and a soon to be installed wood burner.

[strider3700]

Now this is one of those things where I sit back and wonder why I didn't think of it.

it's an on demand water heater that rather then using natural gas or massive amounts of electricity to generate heat it uses electricity to generate microwaves that heat the water.

This should use far less electricity then a regular electric water tank.

The story says it will be launched next week so hopefully this will be easy to get by the time I gut the bathroom in a few months.

http://www.theglobeandmail.com/servlet/ ... Technology

[Dukat_Reloaded]

I don't know about.......

I know my 750watt microwave can boil a glass of water in 2 minutes.

I know my 2200watt kettle can boil 1 litre in a minute.

I don't think it's anymore efficient, the company is most likely spinning the story to get free media attention.

[strider3700]

My hope is more that the wiring requirements may be lower then the standard electric on demand but Yeah I'm now thinking you're correct, it may get hot quicker but it should require close to the same power to heat water.

[Guest]

in case you don't know a microwave works

thats basically all it does
heat water

the energy of the microwave exactly matches the frequency of the bonds between the water molecules promoting them to a higher energy .. something along those lines.. warming up the water

im sure its more efficient to just burn some gas
theres not the conversion loss by doing
burn fossil fuel -> electricity

etc

[Kingcoal]

Electric resistance heaters (such as what is in your electric hot water heater), are 100% efficient already. All the losses are in the heat exchanger; which isn't much. Microwave ovens are not 100% efficient; however there is no heat exchange. Water molecules are caused to vibrate generating heat. I think under the best circumstances, it would be a wash compared to a resistance element unit.

[pea-jay]

$this->bbcode_second_pass_quote('', 'i')m sure its more efficient to just burn some gas
theres not the conversion loss by doing
burn fossil fuel -> electricity

[ubercynicmeister]

As far as I am aware, (unless someone has invented a new type of microwave, recently) microwave heating is a lot less than 100% efficient, and much less efficient that resistance heating (Resistance Is Ohm's Law, as an answer to the Trekkies).

No, I haven't seen the figures, and if someone can point me in the right direction, I'd like to learn some more about it, but as far as I know, microwave heating is less efficient than resistance heating.

[Dukat_Reloaded]

If your using 120volts at 50hz, to convert that to microwave energy, it needs to go through a process to raise the frequency of the AC voltage from 50hz to 2.35 gigahertz which is the frequency which excites water and raises it tempature. At 50hz very little power is lost in high power voltage lines, but as that frequency is increased to 10000 times a second, the power doesn't travel through the cables, it get radiated into the surounding area of the line. That is how radio works, high frequencies radiate power. I would imagine that there would be some loss in converting 50hz power to 2.35gz to heat water.

[Terrapin]

$this->bbcode_second_pass_quote('ubercynicmeister', 'A')s far as I am aware, (unless someone has invented a new type of microwave, recently) microwave heating is a lot less than 100% efficient, and much less efficient that resistance heating (Resistance Is Ohm's Law, as an answer to the Trekkies).

No, I haven't seen the figures, and if someone can point me in the right direction, I'd like to learn some more about it, but as far as I know, microwave heating is less efficient than resistance heating.

[donshan]

This story illustrates an important point about energy and even EROEI calculations.

Converting ordinary grid electricity into microwave energy involves a net loss ( 40%) so microwave energy has a negative EROEI . However microwaves have very valuable properties (including radar), such as the ability to heat frozen water in the middle of a frozen packaged meal, and have it heated to eating temperature in a couple of minutes. Ordinary resistance heating ovens might take a half an hour and use much more total energy in the process of thawing and heating the dinner. Thus microwaves make sense for frozen dinners even with a negative EROEI.

However, since low grade grid power can heat water directly it is much more efficient to use the lower grade power for water heating.

There are many other examples of using higher value energy with negative EROEI. I read that the highly regulated power feeding a Pentium microprocessor at high frequency costs $3.00 per KwH, but this power is worth the extra cost since raw grid power is useless for digital computing. Similarly converting grid power to laser light enables DVD players and laser eye surgery. The EROEI of laser light energy is extremely negative, but extremely valuable at the same time since lasers do useful things grid power alone cannot do.

I still heat a cup of tea in the microwave however.

[Doly]

$this->bbcode_second_pass_quote('donshan', '
')I still heat a cup of tea in the microwave however.