Dankoff vs Shurflo

openplanetopenplanet Registered Users Posts: 34 ✭✭
I'm designing a fairly straightforward system. Dug well with PV-direct submersible SunPump will supply a 500 gal storage tank in the basement of the house (vertical lift of about 20 feet; horizontal run of about 200 feet). Another pump will then pressurize a 40 gallon bladder tank which will supply 40psi to the house. House electrical system is a 1.2kw array that charges 600ah of battery via a Midnite Solar Classic. Question: why should I spend $600 + for a Dankoff Flowlight booster pump to charge the pressure tank when I can buy a Shurflo for less than $200? I'd gladly buy the Dankoff if I could justify it...but so far I've seen no convincing reason. Any thoughts would be greatly appreciated. --Paul

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,511 admin
    Re: Dankoff vs Shurflo

    What is the battery bank voltage?

    Are you looking at DC or 120 VAC for the pump?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • openplanetopenplanet Registered Users Posts: 34 ✭✭
    Re: Dankoff vs Shurflo

    Battery bank is 24v; planning to use 24vdc pump. Thx.
  • vtmapsvtmaps Solar Expert Posts: 3,738 ✭✭✭✭
    Re: Dankoff vs Shurflo
    openplanet wrote: »
    Question: why should I spend $600 + for a Dankoff Flowlight booster pump to charge the pressure tank when I can buy a Shurflo for less than $200? I'd gladly buy the Dankoff if I could justify it...but so far I've seen no convincing reason. Any thoughts would be greatly appreciated.

    I bought the Shurflo. Just understand that there is a quality difference, you get what you pay for. The shurflo is NOT rated for continuous duty and will need rebuilding of the pump head more frequently than the Dankoff. In favor of the shurflo... it can run dry without harm, it is cheap, and you can easily rebuild the pump head. (Dankoff pump head is not user servicable).

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Dankoff vs Shurflo

    Aquatec 550 are 5.5 gpm , 5 diaphragm pumps that have adjustable pressure switches. Available in 12V, 24V or 120V AC. There is also a soft start variable speed in this model. I have some going on 10 years of operation @ 80 psi ( Water Jet Service ). This size of gpm pump really does not need a bladder tank unless you want to run more than 3-4 fixtures at once they work fine in-line as a demand pump on a 3/4 inch line. Most people will set up a demand pump with to small of a supply and discharge trunk line and strangle the pump, then complain about the flow. Off Grid you are just wasting your power resources pressurizing a tank that really does nothing.

    http://www.energybay.org/aquatec-550-pressure-pump-24vdc
    .
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Dankoff vs Shurflo

    I agree that in the OP's case, why bother with a large pressure tank?

    I do almost the same exact thing. I fill a 300 gallon storage tank with my big pump once a week when he sun is out, then draw water from that tank using a sureflo to pressurize the "house".

    However, I ALWAYS use a small 1-2 gallon pressure tank (a hot water heater expansion tank is a nice, small and cheap way to do it), just to prevent the water hammer effect of the pump coming on and off the moment you turn on/off the faucet - which CAN break pipes - even copper pipes.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • Texas WellmanTexas Wellman Solar Expert Posts: 153 ✭✭
    Re: Dankoff vs Shurflo

    Here's the REAL question you should ponder: Why are you even considering a 2nd pump at all? Just let the sun pump do all the work and pump into a large pressurized tank and eliminate the 2nd pump/tank altogether. The only reason for having a 2nd tank is if your well is a slow producer.
  • jcheiljcheil Solar Expert Posts: 722 ✭✭✭
    Re: Dankoff vs Shurflo
    Here's the REAL question you should ponder: Why are you even considering a 2nd pump at all? Just let the sun pump do all the work and pump into a large pressurized tank and eliminate the 2nd pump/tank altogether. The only reason for having a 2nd tank is if your well is a slow producer.

    I would think because it consumes WAY more power to run the big pump, on demand (especially at night) than it does to run the small sureflo. At least that is the case with mine.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • openplanetopenplanet Registered Users Posts: 34 ✭✭
    Re: Dankoff vs Shurflo
    Here's the REAL question you should ponder: Why are you even considering a 2nd pump at all? Just let the sun pump do all the work and pump into a large pressurized tank and eliminate the 2nd pump/tank altogether. The only reason for having a 2nd tank is if your well is a slow producer.

    In answer to your question Texas Wellman: The whole idea of having a large unpressurized reservoir\cistern is so that you can run the SunPump panel-direct, eliminate the batteries, and not have to worry about water supply during periods of low light.

    To others, thanks very much for your insights and suggestions. I have wondered whether it makes sense to eliminate the pressure tank, but thought that one of its purposes is to reduce the frequency of the pressure pump turning on and off, such as when doing dishes. I will definitely look into some of your suggestions. This forum is SO helpful. Thanks again all!
  • openplanetopenplanet Registered Users Posts: 34 ✭✭
    Re: Dankoff vs Shurflo
    Aquatec 550 are 5.5 gpm , 5 diaphragm pumps that have adjustable pressure switches. Available in 12V, 24V or 120V AC. There is also a soft start variable speed in this model. I have some going on 10 years of operation @ 80 psi ( Water Jet Service ). This size of gpm pump really does not need a bladder tank unless you want to run more than 3-4 fixtures at once they work fine in-line as a demand pump on a 3/4 inch line. Most people will set up a demand pump with to small of a supply and discharge trunk line and strangle the pump, then complain about the flow. Off Grid you are just wasting your power resources pressurizing a tank that really does nothing.

    http://www.energybay.org/aquatec-550-pressure-pump-24vdc
    .

    This looks like a very interesting alternative to the Shurflo. Can you elaborate on the "soft start variable speed?" I don't see mention of that in the product lit. Thx!~
    Also...isn't it true that using a pressure tank (larger than the very smallest kind) will prolong pump life because it will reduce the number of on\off cycles? And doesn't that also reduce power consumption because it reduces the increased current draw associated with motor startup? Thx.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,665 ✭✭✭✭✭
    Re: Dankoff vs Shurflo
    openplanet wrote: »
    This looks like a very interesting alternative to the Shurflo. Can you elaborate on the "soft start variable speed?" I don't see mention of that in the product lit. Thx!~
    Also...isn't it true that using a pressure tank (larger than the very smallest kind) will prolong pump life because it will reduce the number of on\off cycles? And doesn't that also reduce power consumption because it reduces the increased current draw associated with motor startup? Thx.


    This pump, the Shurflo's, the Jabsco's, etc are on average going to last maybe 5 years in a real home with normal appliance use. If someone gets 10 years they are the exception. You do get what you pay for and pumps are a pain when they are not right. My experience in marine and offgrid has been the pressure tank helps but the diaphragms just do not last like a quality pump. The power difference is not an issue with these pumps as it is low and there is not a noticeable surge. Definately buy 2! Many times these inexpensive pumps blow the diaphragm and fill the motor with water. Plan for a flood as you would with any pump and good luck!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Dankoff vs Shurflo
    openplanet wrote: »
    This looks like a very interesting alternative to the Shurflo. Can you elaborate on the "soft start variable speed?" I don't see mention of that in the product lit. Thx!~
    Also...isn't it true that using a pressure tank (larger than the very smallest kind) will prolong pump life because it will reduce the number of on\off cycles? And doesn't that also reduce power consumption because it reduces the increased current draw associated with motor startup? Thx.
    Here you go. If I didn't have a experience with any product, I wouldn't post it. Any of the pulsed pumps are going to last longer than the On / Off straight switch pressure pumps. They are more expensive and have a pressure transducer and a electronic control board. They consume more power, but the payback is better. None of these diaphragm type pumps are considered to be continuous duty .

    http://www.rvplus.com/aquatec-pump-aquajet-rv-serie-5.3gpm-55-aquajet-arv.html?CAWELAID=600008500000038801&catargetid=1932139306&cadevice=c&cagpspn=pla&%22cagpspn=pla%22&gclid=CNXFtIPX17oCFa1aMgodgjcAAw

    http://www.rvwholesalers.com/catalog/aquajet-rv-water_pump-10-0025.html?gclid=CLCw09vR17oCFeYWMgodfA0AKw

    One thing I have done in the last few years is to separate the Plumbing Circuits and use two different pumps. There are some things, like Toilet flushing, cold water for a washing machine that receive no benefit from a variable speed pump, they can be powered by a cheaper pump. Variable speed pumps maintain a constant pressure in the supply line. Most that have to use a High Filtration system do this, they do not filter all the water they consume. Any fixture, like a sink where the user controls the flow by the opening of a faucet, there will be benefit, less pump cycling and water wasted, especially hot water. Single Lever faucets consume more water than a double handle faucet. Pressure tanks have a yield factor of about 30%, that means a 40 gallon tank will give you about 16 gallons or less before the pump will cycle again. Pumps have a pumping curve based on the head pressure, a 20 gpm pump @30 psi, may have a .5 gpm @ 50 psi, again, cycling and run time are all important factors in any off grid consideration. It's more about the right pump for the right job, be it $100 or $1,000, your choice. A 5 gpm pump should not be confused with the old time 2, 3 or 4 gpm models.
    .
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,665 ✭✭✭✭✭
    Re: Dankoff vs Shurflo

    I wish I could say that I agreed. I really do! The Shurflo Smart sensor pump was suppose to do all that he Aquatec did. The same with jabsco variable speed. It still failed most of the time with a diaphragm leak. If you are separating the plumbing circuits with 2 pumps of coarse you will get longer life. I would add also that each application is different also and the higher you pump with an inexpensive pump the sooner it will fail.

    No big deal as these are all really nice pumps for what they do. The old standard non variable speed Shurflo is a great pump. It just won't last long and always fails at night. For a cabin or RV, perfect. Starting out in a full time offgrid home I would plan on a re-design later.
    Here you go. If I didn't have a experience with any product, I wouldn't post it. Any of the pulsed pumps are going to last longer than the On / Off straight switch pressure pumps. They are more expensive and have a pressure transducer and a electronic control board. They consume more power, but the payback is better. None of these diaphragm type pumps are considered to be continuous duty .

    http://www.rvplus.com/aquatec-pump-aquajet-rv-serie-5.3gpm-55-aquajet-arv.html?CAWELAID=600008500000038801&catargetid=1932139306&cadevice=c&cagpspn=pla&%22cagpspn=pla%22&gclid=CNXFtIPX17oCFa1aMgodgjcAAw

    http://www.rvwholesalers.com/catalog/aquajet-rv-water_pump-10-0025.html?gclid=CLCw09vR17oCFeYWMgodfA0AKw

    One thing I have done in the last few years is to separate the Plumbing Circuits and use two different pumps. There are some things, like Toilet flushing, cold water for a washing machine that receive no benefit from a variable speed pump, they can be powered by a cheaper pump. Variable speed pumps maintain a constant pressure in the supply line. Most that have to use a High Filtration system do this, they do not filter all the water they consume. Any fixture, like a sink where the user controls the flow by the opening of a faucet, there will be benefit, less pump cycling and water wasted, especially hot water. Single Lever faucets consume more water than a double handle faucet. Pressure tanks have a yield factor of about 30%, that means a 40 gallon tank will give you about 16 gallons or less before the pump will cycle again. Pumps have a pumping curve based on the head pressure, a 20 gpm pump @30 psi, may have a .5 gpm @ 50 psi, again, cycling and run time are all important factors in any off grid consideration. It's more about the right pump for the right job, be it $100 or $1,000, your choice. A 5 gpm pump should not be confused with the old time 2, 3 or 4 gpm models.
    .
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Dankoff vs Shurflo
    I wish I could say that I agreed. I really do! The Shurflo Smart sensor pump was suppose to do all that he Aquatec did. The same with jabsco variable speed. It still failed most of the time with a diaphragm leak. If you are separating the plumbing circuits with 2 pumps of coarse you will get longer life. I would add also that each application is different also and the higher you pump with an inexpensive pump the sooner it will fail.

    No big deal as these are all really nice pumps for what they do. The old standard non variable speed Shurflo is a great pump. It just won't last long and always fails at night. For a cabin or RV, perfect. Starting out in a full time offgrid home I would plan on a re-design later.
    Sorry for your bad luck. One thing I can guarantee, somewhere out there as I type this there is a pump failing for some reason.
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,665 ✭✭✭✭✭
    Re: Dankoff vs Shurflo
    Sorry for your bad luck. One thing I can guarantee, somewhere out there as I type this there is a pump failing for some reason.

    I wish it was just my bad luck. Too many customers tried these. After the boat life, I try and use the best. They are gravity fed rainwater....:D
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • openplanetopenplanet Registered Users Posts: 34 ✭✭
    Re: Dankoff vs Shurflo
    Here you go. If I didn't have a experience with any product, I wouldn't post it. Any of the pulsed pumps are going to last longer than the On / Off straight switch pressure pumps. They are more expensive and have a pressure transducer and a electronic control board. They consume more power, but the payback is better. None of these diaphragm type pumps are considered to be continuous duty .

    http://www.rvplus.com/aquatec-pump-aquajet-rv-serie-5.3gpm-55-aquajet-arv.html?CAWELAID=600008500000038801&catargetid=1932139306&cadevice=c&cagpspn=pla&%22cagpspn=pla%22&gclid=CNXFtIPX17oCFa1aMgodgjcAAw

    http://www.rvwholesalers.com/catalog/aquajet-rv-water_pump-10-0025.html?gclid=CLCw09vR17oCFeYWMgodfA0AKw

    One thing I have done in the last few years is to separate the Plumbing Circuits and use two different pumps. There are some things, like Toilet flushing, cold water for a washing machine that receive no benefit from a variable speed pump, they can be powered by a cheaper pump. Variable speed pumps maintain a constant pressure in the supply line. Most that have to use a High Filtration system do this, they do not filter all the water they consume. Any fixture, like a sink where the user controls the flow by the opening of a faucet, there will be benefit, less pump cycling and water wasted, especially hot water. Single Lever faucets consume more water than a double handle faucet. Pressure tanks have a yield factor of about 30%, that means a 40 gallon tank will give you about 16 gallons or less before the pump will cycle again. Pumps have a pumping curve based on the head pressure, a 20 gpm pump @30 psi, may have a .5 gpm @ 50 psi, again, cycling and run time are all important factors in any off grid consideration. It's more about the right pump for the right job, be it $100 or $1,000, your choice. A 5 gpm pump should not be confused with the old time 2, 3 or 4 gpm models.
    .

    Thank you. It looks like the AquaJet isn't made in a 24 vdc version, unfortunately. So...do I take it you don't think the higher quality and longer life expectance of a Dankoff Flowlight Booster is worth the extra cost?
  • ILFEILFE Solar Expert Posts: 364 ✭✭
    Re: Dankoff vs Shurflo
    vtmaps wrote: »
    I bought the Shurflo. Just understand that there is a quality difference, you get what you pay for. The shurflo is NOT rated for continuous duty and will need rebuilding of the pump head more frequently than the Dankoff. In favor of the shurflo... it can run dry without harm, it is cheap, and you can easily rebuild the pump head. (Dankoff pump head is not user servicable).

    Exactly the reason to go with a ShurFlo Pump, especially in a very rural area.

    Keep spare parts for the pump head, and you can work on it yourself, if / when the time comes.
    Paul
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Dankoff vs Shurflo
    openplanet wrote: »
    Thank you. It looks like the AquaJet isn't made in a 24 vdc version, unfortunately. So...do I take it you don't think the higher quality and longer life expectance of a Dankoff Flowlight Booster is worth the extra cost?
    I had forgotten that the Variable speed was only in 12 V.

    I think they ( Dankoff ) are a fine pump, worth the money ? Only you can answer that. Keep a inlet filter on them. Vane pumps wear rather quickly without one.
  • Texas WellmanTexas Wellman Solar Expert Posts: 153 ✭✭
    Re: Dankoff vs Shurflo

    Depending on your water habits and the size of your pressure tank it may not take much more if any power to just use one pump.

    You're pumping the same water twice. You could fill a large (120-220 gallon) pressure tank using the sun pump and a regular pressure switch. When the pressure switch ran low the sun pump would come on and re-fill the big tank and you would be able to use approx. 20-50 gallons of water depending on the size and type of tank you have before the pressure switch would call for the pump to kick back on (normal cycle). The avg. family of 4 uses between 200-300 gallons of water per day. Let the big pump fill the tank during the day. Connect the sun pump in tandem to your existing batteries and panels so that it has power available at night. Assuming your sun pump pumps about 5 gpm you could fill the pressure tank in 4-10 minutes (20-50 gallons to fill the tank on a normal draw down, not from an empty state), again depending on how big your pump is and how big your tank is.
    jcheil wrote: »
    I would think because it consumes WAY more power to run the big pump, on demand (especially at night) than it does to run the small sureflo. At least that is the case with mine.

    But you didn't eliminate the batteries, you still have them to run your small pump. Again, you are pumping the same water twice, and might be using more power to do it. If the sun pump consumes 600W (guesstimate) but only runs for 4-5 minutes to fill the big tank but the smaller pump only uses 200W but takes 12-20 minutes to run you have not saved any power.

    If you TRY to keep all your water needs during the day when you have sun light and figure out a way to top off your large pressurized tank you will still have somewhere around 20-30 gallons of usable water with a large pressurized tank you can still use at night to flush the toilet, brush your teeth, etc. before your pump ever comes on. You're still going to pump the same exact amount of water but you're going to do it with two pumps.

    I can see using the smaller pump if the larger one is a major energy hog or the small one really puts out the volume but for some reason it isn't quite making much sense to me especially if you have batteries. The sun pump is already energy efficient (or should be) and probably pumps the water just as efficiently as the smaller shurflo.
    openplanet wrote: »
    In answer to your question Texas Wellman: The whole idea of having a large unpressurized reservoir\cistern is so that you can run the SunPump panel-direct, eliminate the batteries, and not have to worry about water supply during periods of low light.

    To others, thanks very much for your insights and suggestions. I have wondered whether it makes sense to eliminate the pressure tank, but thought that one of its purposes is to reduce the frequency of the pressure pump turning on and off, such as when doing dishes. I will definitely look into some of your suggestions. This forum is SO helpful. Thanks again all!
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,665 ✭✭✭✭✭
    Re: Dankoff vs Shurflo

    It may be that the well is remote from the batteries at the home. This happens and is just something that you deal with offgrid. Your point is a good one about pumping twice but it may be the cost of doing business, as they say. I did not read the whole thread....
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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