Over the past few years, I've tried to make my house less wasteful and more efficient. I've managed to cut my water consumption down about 10% (it was never high to begin with) and I've managed to reduce my electric consumption down by a full 30% across the board (50% in the winter!).
My question now is as it relates to tankless water heaters. My house does not have natural gas. So I'm going to stick with an electric water heater. I'm going to be ordering a more efficient one in the next few months, but I still have an issue as it relates to hot water at the "tap".
In the bathrooms, and the kitchen sink, it can take up to 4 minutes of running on full heat before any hot water comes out. It's not a matter of tank temperature, because once the hot water comes, it's plenty hot... but there is just that huge delay period between when the hot water comes and I first turn on the tap.
I know that there are several small 110-volt electric tankless water heaters that are available. My thought was, I would install these small "instant" water heaters in the master bathroom, and under the kitchen sink. They ONLY turn on when it detects a loss of pressure in the lines (IE: the faucet is activated). They heat instantaneously, and will provide adequate heat to the water until the heated water from the wate heater can catch up.
There were a couple of solutions to this, wrap the heater lines... but I live in South Florida, and my water lines run through a concrete slab (so that's not an option).
I'm still researching the requirements, but as far as I know, this seems to be the best solution. I was wondering if anyone had any experience with these "point of use" water heaters. And also, I was wondering if there was a model that "shuts off" when the incomming temperature reaches a certain temperature so it doesn't keep heating at the faucet. Basically, I don't want the point of use water heater to run continuously, even after the hot water has reached it from the tank...
Any thoughts, suggestions, or advice is really appreciated!
Oh, I also wanted to know if anyone noticed an increase in cost associated with these. My water bill isn't too costly at this point, but if these point of use heaters will increase my power bull by $20 a month, then it's not worth it. I realize this is based more on frequency, but I'm just trying to determine how to make it less wasteful:
1) 4 minutes of constantly running water (wasted)
2) 25amps @ 120volts running for less than a minute.