Can anyone direct me to a source for a residential water flow gauge that measures GPM? Looks very similar to a regular pressure gauge. Not looking for a combo pressure/flow tester. Too expensive. Just need a flow gauge.
Thanks for any help,
Michael
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Replies
http://www.inspectortools.com/dualwatpresa.html
Google is our friend.
...or.....get yourself a 5 gallon bucket and see how long it takes to fill it up.
You get out of life what you put into it......minus taxes.
Marv
"get yourself a 5 gallon bucket and see how long it takes to fill it up."
Great idea! Thanks.New knowledge is priceless.
Used knowledge is even more valuable.
Stop watch. Put the hose in the bottom of the bucket as it fills.
Joe H
The bucket trick may not give you an accurate flow rate. You're measuring the time to fill a bucket through a valve and a length of hose. They have more resistance to flow than a pipe so the flow rate will be lower.
"They have more resistance to flow than a pipe so the flow rate will be lower."OTOH, the water will have to flow through a valve at some point and it's not going to flow faster in the pipe than in the valve once the tankless heater is installed. Probably the best place to test flow rate is at the shower head and the washing machine, maybe the dishwasher. Those will usually use more hot water than anything else in the house.
"I cut this piece four times and it's still too short."
You're right about checking flow rates the big hot water users although checking the actual flow rates into a washing machine or dishwasher may be a problem since they're fed thru solenoid operated valves.
When I made that earlier post, I didn't know that the OP was sizing a tankless water heater. - lol
For what purose?
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
"For what purpose?"
Examining the potential benefit of going tankless, especially electric vs. gas. I prefer a total electric house and the climate here in S.C. isn't as harsh as the areas where tankless units usually get tested the most. With that in mind, I'm exploring the true capabilities of my system in order to make the most informed purchasing decision I can.
Currently looking hard at the Seisco RA-28. If anyone cares to weigh in -- positively or negatively -- I'd certainly welcome the feedback. This will require me to invest some serious cabbage any way I go, so I want to get it right the first time.New knowledge is priceless.
Used knowledge is even more valuable.
Just installed a Stiebel-Eltron Tempra 24 in my house. Bought the unit online for $436.95 from a dealer in Florida on ebay (philbertfl). It serves a bathroom, washer, dishwasher, bath sink, and kitchen sink. We live in NW Ohio, and the coolest incoming water temp should be around 39 degrees.
You must have a 200 amp electric service minimum. You will notice dimming of lights, etc., when the unit is on. In talking with my electric power rep, he said if this is a big problem, that they will check the drop from the power pole to the house. I have not done that yet, but will probably do that soon.
When the washer is set to warm water, the heater will keep up if I have the heater set no higher than 118 degrees. When the water is colder this winter, I will need to slow the flow of water to the washer on both the hot and the cold if I want/need warm water for washing.
If someone is taking a shower, you would refrain from running hot water anywhere else. They do make larger units, which the one you are looking at probably is. I am assuming it is a 28KW unit. Mine is a 24KW unit. Depending on how many bathrooms you will be supplying would depend on the size of the unit. When I get my other bathroom done, I will be installing a smaller unit since it will only be supplying it.
I used a 5-quart bucket under my shower head at wide open to see how much water I was using, and found that it supplied 1.5 gpm. Then I looked at the chart for my water heater along with the coldest incoming temp that I expected to make sure that we would have hot enough water this winter for a shower. I am not into cold showers.
Hope this information helps.
Bryan
"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Edited 7/30/2007 10:47 pm ET by BryanKlakamp
"Hope this information helps."
Thanks, Bryan. Comments from an actual user are more helpful to me than the promos offered by the distributers.
What affect has the 24KW unit had on your electric bill?New knowledge is priceless.
Used knowledge is even more valuable.
I installed it exactly two weeks ago.
Therefore, I have no idea at this point. They use the figures of 10% to 15% savings on your water heating portion. If you are looking for instant payback, forget it. Long term, you may be ok. I did mine myself, and with the cost of the heater, wire, breakers, and reworking the plumbing, I probably have $700 total in it. You can purchase a tank heater for considerably less, and is much easier to install if you are looking at replacing an existing unit. If, on the other hand, this is new construction, it will be easier and you won't be duplicating electrical circuits.
Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
"If you are looking for instant payback, forget it."
I'm doing a whole-house remodel. I gave up on saving money a few thousand splinters ago.
"I did mine myself, and with the cost of the heater, wire, breakers, and reworking the plumbing, I probably have $700 total in it."
I'll be doing my own install as well, but I expect a somewhat larger investment upfront. I had planned to go with a 28kW unit, but I'm mulling over the idea of purchasing two 14kW units instead. I'd like to work out a strategy that would use one unit for the sinks and showers, and automatically bring the second unit into the system only when the laundry or tubs are utilized. The cost of installing two 14kW units would be slightly higher than one 28kW (about $200 more), but if my strategy is doable, it would almost certainly pay for itself in due time. I'm sure it wouldn't handle simultaneous applications, but that's not a big issue with us anyway. There would be an additional benefit as well if this works. The 28kW units have a total of four heating elements. Two 14kW units also have a total of four elements. Same total amperage demand either way. However, if one 14kW unit fails, I'll still have hot water available while I repair the other. If one 28kW fails, I'm SOL until repairs are completed.
"You can purchase a tank heater for considerably less.."
Nah. I want to get away from the expense of perpetually heating and storing water that gets marginal use.New knowledge is priceless.
Used knowledge is even more valuable.
You'll need a flow sensor that activates a solenoid that activates an electric valve and a 14KVA mag switch.The valve opens flow to the second heater, and the mag switch turns the juice on.SamT
Sam,
I think I understand what you are saying. But, if he puts them in series, that would not be required? Only if he wants to install them in parallel would he need to do that, correct?
Bryan
"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Edited 7/31/2007 10:16 pm ET by BryanKlakamp
In series would be simpler, just skip the electric valve.The units probably just have a go/no-go flow switch, so. . .If the units have inlet temp sensors, he could maybe set the second one to not turn on below about the output temp of the first. Even if not, a temp sensor might be a better choice than a flow sensor.Whatever, the switching has got to handle 14KW.Meself, I would plumb them in zones, then add crossover valves for when one dies. No fancy stuff, just gotta go turn valves in emergencies.SamT
They have modulating heater that are controlled by the discharge tempature. So as long at the tempature out of the 2nd unit is less than the setpoint it won't turn on.The only potential problems is if the internal piping is not big enogh to handle the higher flow..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Well, there you go.SamT
"They have modulating heater that are controlled by the discharge tempature. So as long at the tempature out of the 2nd unit is less than the setpoint it won't turn on."
Correct.
"The only potential problems is if the internal piping is not big enough to handle the higher flow."
3/4" inlet and outlet on both the 14kW and 28kW. Not sure what the max gpm for 3/4 is. I should note that I plan to install Pex throughout. That will assist the flow somewhat.New knowledge is priceless.
Used knowledge is even more valuable.
The unit I installed has 3/4" connections, but it is restricted to about 1/2" or less due to the internal piping of the unit. I did notice a reduction in flow on the hot side, but not enough to make a big difference. Just something to get used to.
By using pex, if it is 1/2", you will be reducing the flow anyway, although it is said that 1/2" and home runs will give you about the same amount of flow as a conventional 3/4" and 1/2" copper installation.
Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Have been thinking about your setup the last couple of days.
Would be curious what the manufacturer would say about it.
Wouldn't hurt to ask.
Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
"Have been thinking about your setup the last couple of days. Would be curious what the manufacturer would say about it. Wouldn't hurt to ask."
I contacted Seisco and spoke with a tech rep there earlier this week. He said that my configuration (2 14kw's in series) would work just the same as one 28kw unit. He also confirmed that one 28kw unit is simply 2 14kw units in one housing. Of course, like all the other manufacturers I spoke with, he said the effectiveness of any electric tankless will be directly related to the demands placed on the system.
I've already ordered the units. However, I'm still roughing in so it will be awhile before I can report the results.
MichaelNew knowledge is priceless.
Used knowledge is even more valuable.
Bryan,
Just wanted to update you on my insane experiment. I purchased a "third" tankless unit yesterday. It's only 9kW, but I plan to use it to preheat the water entering my two 14kW units. It was purely an impulse decision, but it was brand new and the owner let me have it for $90. Not a bad bargain when they routinely sell for around $400.
The 9kW unit requires a double 40A breaker. Combine that with the two 14kW units, and I'll now have a potential demand of 160A on my 200A service. Obviously not gonna work if that happens. My hope is that the 9kW unit will significantly reduce the temp rise needed by the 14kW units, thus keeping the power modulation at a minimum draw.
I have two or three configurations that I plan to experiment with. I'll have about $950 in all three units, not counting breakers and wire.
Let us know how your unit is impacting your electric bill. If you get a chance, check your incoming water temp and the maximum current draw of your unit. I'm sure there are lots of folks here who would be grateful for more "real world" feedback and less of the marketing hype from the various manufacturers. New knowledge is priceless.
Used knowledge is even more valuable.
I wouldn't call it an insane experiment, just uninformed.Let's say your demand at some given time is x Gallons per minute. It will take Y KiloWatts per minute to heat that water.If you have one heater that will do the job, it's output will be Y.If you had 100 heaters in series, the total output will still be Y. Plus a tiny bit for control use and another wee bit for loss. Call the total loss per heater 0.01%If 2 14KW units can supply your max load, no additional units will save money or provide any usable additional hot water over your max load.Because it always takes Y kilowatts to heat X gallons. Using an electric heater to preheat the input to an electric heater that is already capable of handling the maximum flow is... uh... oh yeah,...Insane(|:>)IMO, you should dedicate the 9 KW unit to the washer, IF, it's big enough to handle the maximum flow the washer needs.SamT
"Let's say your demand at some given time is x Gallons per minute. It will take Y KiloWatts per minute to heat that water."
I believe this to be a mistaken assumption. As I understand the technology of these units, the calculation is more correctly stated by saying it takes "Y" kilowatts per degree of temperature rise to heat the water. The 9kW unit has a 3/4" inlet and outlet. The 14kW's also have 3/4" inlets and outlets. If the 9kW feeds the 14kW's in series, the flow rate (time) will be a constant, relative to the demand at the fixture. However, if the 9kW feeds the 14kW's -- and the 14kW's are plumbed in parallel -- the flow rate will be "effectively" cut in half as the water passes through the two 14kW units, allowing more heat conduction into the water without necessarily modulating more power to the elements. As the water leaves the units, it will once again return to a 3/4" line at the home run manifold. From there, it will be further reduced to a 1/2" line. So, the net flow will be determined by net area of all the internal plumbing and the fixture(s) which are being served at any given moment.
I thank you for the feedback and welcome the input. I need all I can get.
MichaelNew knowledge is priceless.
Used knowledge is even more valuable.
No, I'm not mistaken. You can assume any delta T you want and the statement made is still true. Total system watts per degree per volume is the same no matter how many elements you use.SamT
Where does your concern for cycling the elements rest? Seisco does not post schematics, but from looking at their patents, they are pulse width modulating the triacs which drive the elements, or in other words they are being constantly turned on and off anyway, probably at 60Hz.
Hilltop
Michael,
One possible problem I can see if you put the two 14 kw units in parallel and not in series. It takes a certain amount of flow through the heater to turn on the element(s). By installing them in parallel, you have now cut that flow rate in half through each one, and may only get warm water from your 9 kw unit, until you open a faucet far enough. Probably would not affect a shower, or some other high volume user. Although, if it won't turn on until higher than .75 gpm each, then you might have trouble with your shower if it puts out 1.5 gpm like my shower.
Something to consider.
Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Michael,
Just wanted to see how your "experiment" was going.
I finally contacted the power company through email this evening to ask them to check on the power being supplied to my home.
I had talked to my neighbor who said they have noticed that their lights dim at different times during the day. That would indicate to me that there is not enough power being supplied to our neighborhood to fulfill our demands.
The power lines and transformers for our area are probably 50 years old. Who knows when they were installed.
Now that it is winter, if we are taking a shower and someone turns on some warm water, the person in the shower gets a cool or cold shot of water. No fun, unless you have fallen asleep because you've taken a long shower knowing that the tank isn't going to run out, and you need to wake up.
As far as power usage, I haven't checked our bills. My wife takes care of paying them, and I don't look at them.
So, how's yours working?
Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Good to hear from you again, Bryan. My project has been severely delayed due to health problems. I just got the rough-in inspection last week. It will likely be a while longer before I have an answer for you.
Did you go with a manifold setup? New knowledge is priceless.
Used knowledge is even more valuable.
No. I replaced an existing tank water heater. Other than putting the tankless in in place of the old one, I was able to replace the main valve with a ball valve.
I put a meter on my main panel to check the minimum and maximum voltages coming into the house. So far this evening the low has dipped to 214 volts.
Hopefully the power company can do something to help me out.
I'm concerned that my appliances will suffer from not enough voltage. I don't know what effect low voltage has on compressors, microwaves, etc.
Maybe someone else here can tell me.
Thanks, Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
A further update on my conversations with the power co.
When I checked with them to see when they were going to come by and check my problem, they said that they had checked the voltage at my meter at 2 p.m. one day last week. They said that it checked out OK, and that I should check with an electrician to see if there was a problem with my electrical wiring.
After a couple of emails back and forth, they said that they would look into it a little more. I received a call from a local AEP rep a little later that day. He said that they weren't going to send anyone out to look at it.
Now, you might be thinking: Wow! Won't even come back?
What he next said was: I can see from the power grid map that we are going to have to do some rewiring. The transformer that serves your 10 - 12 homes is no longer large enough to handle the power requirements, especially with your home having an electric tankless water heater.
He told me that in 2 - 3 weeks, they would be doing some work to upgrade the service here. It would probably include extending the primary and installing an additional transformer. They would also look at the wire servicing our meter, and possibly upgrading it as well.
He said that they want to sell us electricity, and it was their responsibility to provide sufficient current for us.
Once that happens, I will try to update here with what has happened, and what improvements I see in water heating capacity.
Bryan
"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
Edited 1/21/2008 10:20 pm ET by BryanKlakamp
"You'll need a flow sensor that activates a solenoid that activates an electric valve and a 14KVA mag switch. The valve opens flow to the second heater, and the mag switch turns the juice on."
Thanks, Sam. I'll keep that option in mind.New knowledge is priceless.
Used knowledge is even more valuable.
mw
I looked at your profile, and your picture looks eerily familiar to one I remember as a kid. Do I know you? ;-)
Anyway, I will assume that you intend to install these two units in series, not parallel. If that is the case, the second one will not come on unless the demand is high enough.
I guess that would be one way to have a backup, as you mentioned. How many circuits and what size circuits do these units require?
Bryan"Objects in mirror appear closer than they are."
Klakamp Construction, Findlay, Ohio - just south of the Glass City
"I looked at your profile, and your picture looks eerily familiar to one I remember as a kid. Do I know you? ;-)"
Great pic, huh. I think it captures my best features.
"Anyway, I will assume that you intend to install these two units in series, not parallel. If that is the case, the second one will not come on unless the demand is high enough."
It would have to be a series configuration to boost the heat output. A parallel configuration only serves to boost flow. However, sinks and standard shower heads are more "self-limiting" regarding flow, while the tub or washing machine would place a greater demand on the elements to keep pace. With that in mind, I'm theorizing that one unit would have an adequate sufficiency for the sinks and showers (assuming one application at a time), and a second pair of elements could be energized when needed to add additional heat to keep up with the demand of a larger fixture like the tub or washer. Remember that it's all about temperature rise with tankless, and the second unit wouldn't have much of a temperature rise to contend with since its input would be the output of the first unit. Also keep in mind that I live in S.C. where the "average" groundwater temp is 55-65 degrees to begin with.
"I guess that would be one way to have a backup, as you mentioned. How many circuits and what size circuits do these units require?"
One 28kW: 4 x 30A breakers = 120A
Two 14kW: 2 x 30A "each unit" = 120A
If you look at the guts inside most tankless units, you'll find that the 4-chamber models are simply two 2-chamber models joined at the hip. One of the manufacturers points this out in their literature. You get pretty much the same performance with one 28kW or 2 14kW's. You obviously have to pay a little more to purchase and install two units, but it could prove to be beneficial from a practical and financial standpoint. I'm still "siphering" on it. I appreciate the feedback that you guys are providing.New knowledge is priceless.
Used knowledge is even more valuable.
Just a word of caution on using the shower as a flow rate guide. Most new shower heads have flow restrictors built into them (1.5 gal./min) so you would only be measuring what the shower head allows to pass. Better to open a valve at the washer location and check it there.
(Probably best done using a 90 deg open/closed valve if you are timing the operation.)"Poor is not the person who has too little, but the person who craves more."...Seneca
Tankless? Savings are 'line losses' if you have a long distance to your water heater and tank losses if you use the water only occasionally. Great for an application that is far from the tank where you want water right away ... e.g. a kitchen sink.
Tankless is often being oversold as the answer to everything. Like anything ... if you want it done fast, it will cost, energy wise.
Consider solar water heating ... various options from the Mexican rooftop black tank to modern active systems w/ a pump & controls. Even a preheat tank sitting outside in the sun can reduce your heating requirements.
Everything has its place ... even tankless. Success is knowing when to use what, what for, and why ... and for how much.
"Even a preheat tank sitting outside in the sun can reduce your heating requirements."
Interesting idea. I've been trying to figure out ways to exploit untapped energy to preheat my incoming water supply and reduce the needed temperature rise at the inlet to the tankless unit. I have a private well, so my pump and pressure tank are located in a "pump house" adjacent to my home. Let's see...maybe a second, supplemental tank....then a solar tube on the roof of the pump house directly above that tank...with a lens like you would find in a magnifying glass...
hmm...New knowledge is priceless.
Used knowledge is even more valuable.
If you heat the house efficiently (and have the room inside), an old water heater (stripped of it's insulation) or old pressure tank (with dead bladder) can be used inside as a tempering tank. Or you could just zig-zag 30-50 feet of pipe. Removes heat in the summer and absorbs (the hopefully cheap) house heat in the winter.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
"Or you could just zig-zag 30-50 feet of pipe."
I've got the heat pump going in my remodel even though the interior is still gutted all the way to the roof. It was 95 degrees at floor level (gotta love S.C. summers). Out of curiosity, I used my IR thermometer to see what the temp was on the underside of the roof deck. It was 139 degrees.
So I says to myself, I says, "Self, there's gotta be a way to take advantage of all those free btu's". The first idea that came to mind was something resembling a floor radiant heat system, but attached to the bottom of the roof. The coils could absorb said btu's and bring them to said tempering tank. But how to get water to attic without the cost of pumping?
Perhaps some kind of siphoning system...New knowledge is priceless.
Used knowledge is even more valuable.
Just a single cycle through the loop (no tank needed) should be reasonably effective in warm weather. Of course, the pipe will sweat, so you'd have to take that into account.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
" Of course, the pipe will sweat, so you'd have to take that into account"and freeze..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Depends on where you live, and whether you're careful to drain the loop in cold weather.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
That means two lines from the pump house ... hot and cold.
Just don't forget. Also, whatever works for you and your application. In Mexico, they all use the black rooftop tank, although I know little about it's overall effectiveness ... e.g. longevity of the plastic tank, temperature rise, etc. Often 'hot' water is not a big issue ... warm water is often considered OK (maybe except for washing dishes).
The Mexican (and south Texan) rooftop tank is interesting. Black poly (or some similar plastic). It's non-pressurized, filled with a valve like a toilet fill valve (but with the pipe entering from the side rather than the bottom), and gravity fed to the places where the water is used.And, as I said elsewhere, useless in January in Rio Bravo.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
You already have one. It's called your water meter. It has to be very accurate.
Just turn off all the other water outlets in your house, turn on whatever you want to measure, go to your meter with a stop watch and watch the needle spin around. Then do the arithmatic [conversions, etc.].
~Peter
If it measures in cubic feet there are almost exactly 7.5 gallons per cubic foot.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
We were told is was 7.46 gal/ft³, and 8.33 lb/galI assume this was at STP.
"I cut this piece four times and it's still too short."
"You already have one. It's called your water meter."
Municipal water service isn't available out here in the stix. I'm on a well system. No meter. New knowledge is priceless.
Used knowledge is even more valuable.
http://search.store.yahoo.com/cgi-bin/nsearch?follow-pro=1&vwcatalog=hogslat&catalog=hogslat&query=water%20flow%20meter
Use them for flow meter in poultry barns. $90