[cthomson]

Hey guys this is my first post, and probably will have many more coming soon. My wife and I just bought our first home. We both just graduated college, and bought a "fixer upper". I have all the electrical completed, and am now starting on the plumbing. I have been looking at water heaters, and have a few questions.
First off, my uncle had the house, and there is a 40 gallon water heater already there to use. So, I will definitely use that since it will save me some money on the front end. My question is this though: I have been contemplating running some type of timer on the water heater, and decreasing the temperature at which the heater operates. Along with this I would install some smaller tank less water heaters in the kitchen and bathroom (I found some small 2 gpm ones for around 200-300 dollar range). I would probably buy two of them, one for the bathroom and one for the kitchen. I was just curious if anyone has done this, and what kind of energy savings I would be looking at? Is it worth the money or am I just wasting it?
P.S. All I have is electric, no gas. I may have been very vague. So, if you have any questions about my specific application please ask.

Thanks Again

 

[Just Bill]

The small tankless units generally don't have sufficient volume for a shower, but are OK for sink use. Turn down the temp, they can put out VERY HOT water.

I am assuming the heater is electric?? You can connect timers to them, but keep in mind it takes a while to reheat water, so it may not be the saver you expect. Just keep the water temp set at about 120 deg. That is the best you can do with a tank type heater.

As for whole house tankless units: they generally cost 2-3 times what a tank heater costs. Last maybe 1/3 longer, but do provide energy savings over their life. Not sure of real savings over time. They love them in Europe.

 

[Daniel Holzman]

I installed an electric heat pump type water heater in my basement. At least two companies now make them, mine is a GE, I think Rheem makes one also. Considerably more expensive than a standard water heater, my 50 gallon unit cost about $1400, however you are eligible for a tax credit in the US, which amounts to a reduction of about $400.

The heat pump systems extract heat from the air, which means that the cost to operate is about half that of a standard electric heater. Since my home state of Massachusetts has about the highest electric rates in the U.S. this is significant, in fact it amounts to close to $500 per year in electric savings.

I save a few extra dollars by venting my electric dryer into the basement. This is normally not a good idea, except that since the water heater acts like a big dehumidifier, it extracts the moisture from the air that the dryer puts out, so you recover a portion of the energy used to dry clothes. If you use such a technique, make sure you have a system that collects the lint (I use a sock over a special dryer valve).

 

[cthomson]

Thanks for the replies guys....Just curious i know the flowrate is something like 2.2gpm at 80 psi for most shower heads, but my pressure is going to be around 50-55 psi.....Just curious if you know of a common flowrate for that psi? Just wanting to price some that give me the flow I need for a shower.....

 

[Daniel Holzman]

At 55 psi you will get approximately 80 percent of the flow that you would get at 80 psi. The flow rating for a showerhead is typically stamped on the head in gpm, I think the standard is to show the flow rate at 80 psi.

 

[cthomson]

o.k. so is there an approximation formula that I could use? It has been a while since I studied Bernolli's equation, will that give me the estimated flow?
Just having some trouble understanding is all. I'm saying that because the tank less units I described were rated at 2 gpm I believe, and if it decreases proportionally, then that would put me around 1.8 gpm flow with 55 psi?????
Or, are you saying that it's not necessarily 2.2 gpm flow and I would need to pick out a shower head before I decided to do that?

Thanks again, sorry if I ask to many questions

 

[CyFree]

I am not sure about pricing on tankless heaters but it seems to me that for the price you will pay to buy and run two smaller units and the conventional tank heater, you will probably be able to replace them all for a big, whole house unit.
That, of course, depending on your family's habits and consumption.

In any case, before you go through the expense, I suggest you consider getting the maximum performance from the existing water heater by turning down the thermostat, insulating the tank to curb stand by heat loss, and the hot water pipes. Install water saving aerators in the faucets and shower heads and things like washing your clothes in cold water go a long way to save you money and energy.

Here's a video on tankless water heaters and what to look for.

http://youtu.be/1ztO0LBcvs8

 

[Done That]

Water heaters in reality just don't use a lot of $ on an annualized basis to run...so as others mentioned turn down the temp, add an insulation blanket and that's about it.

Half your bill typically comes from the HVAC in the house...so focusing on a more efficient system, or having yours serviced to make sure it is performing as it should might be a better payoff for your time and efforts...this includes attic insulation, windows, caulking and weatherstripping, as well as a programable thermostat. Just some ideas to consider, because even if you cut the water heating bill in half you have not put that much $ in your pocket. Good luck.