Could a water meter measure the cold water supply to my residential water heater?
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| Posted in Mechanicals on
I would like to measure my hot water use, not approximate it with water audits. First, the cold water supply pipe to the water heater is smaller than the supply pipe for the whole house. Is it possible to put a gauge or meter on this smaller pipe just before it enters the water heater without impeding flow or water heater function? Second, if so, can you recommend a reliable meter or a company that might carry a product like this? Thank you.
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Replies
Bruce,
A water flow meter can easily be installed at the cold water intake for your water heater.
Google "water flow meter" and you will get plenty of results if you want to buy the meter online.
I don't know which models are most dependable. Any other readers want to suggest a good meter?
Make sure you get the right gauge. Are you wanting to measure gallons per minute flow rate or total gallonage (as your house meter does)?
Martin and Robert,
Thanks for your prompt replies. I don't have much time as the water heater gave out and I'm having a new one installed at the end of the week. I figured installation time is the best time to put in a gauge.
I currently track my overall water usage by converting the cubic feet measured by the water meter into gallons, but I'd like to break the hot water component out of that total usage. Then, after taking water conservation measures, it'll be easier to see how the hot water use was affected by comparing to prior readings. So, now that you made me think about it, I realize I'll need a total gallonage gauge! But, though it does not have to show the flow rate, it will have to measure the gallonage being used by very low flow rates. For instance, warm water from a 0.5 gallon per minute (gpm) bathroom faucet might only be using 0.25 gpm of hot water - so the gauge needs to be sensitive enough to add this to the total gallonage.
I found an analog meter with an extra-large chamber for the water to flow through so that debris does not build up (my plumber said the galvanized pipes have rust particles in them and therefor any gauge should be debris-tolerant). This sounds very promising but it does not re-set. So I have two questions...
First, will a total gallonage meter impede flow and alter the function of the gas-fired tank hot water heater?
Second, have you heard of a debris-tolerant total gallonage water meter that can be re-set?
Thanks!
Bruce
There are a thousand options for meters. Some are analog, some digital. Some have USB data outputs to a computer. The simplest (and typically resetable) ones are made to connect to a garden hose, but that's not what you want.
Basic analog meters are not resetable, but keep track of cumulative gallons. The MN-M20USG on this page (http://www.plumbingsupply.com/wameters.html) would work in your application and has a dial that registers increments of 1/10 gallon. Such meters use an impeller to magnetically operate the register, are tolerant of the usual water-borne debris, do cause some pressure-drop (see chart on web page), but will not impede the function of a tank-type water heater. You will need the unions to connect the meter to your water line, as well as adapters to go from the copper pipe to the male NPT threads of the unions.