Softener system for new home - ATTN GARY

Discussion in 'Water Softener Forum, problems, installation and r' started by nofears67, Jan 26, 2010.

  1. nofears67

    nofears67 New Member

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    186
    Peter,
    The main line to the home is a 2" pvc line coming from a well capable of producing 60 gpm. The pressure entering the softwater system should be about 65 psi under flow conditions. I plan to run 1.25" or 1.5" hot and cold lines to the bathrooms and then 1" branch lines to each 3/4" Kohler thermostatic valves (spec'd to flow 15 gpm @ 60 psi). There will be two of these valves in each shower, both on a dedicated 1" branch. All heads will be on 3/4" pressure balance loops.

    Bob,
    I plan to have two (2) Bradford White High Performance GX‑2‑25S6SX 25 gal propane water heaters installed in series. Each one can put out 155 gals of hot water in first hour. I see your point about the 10 min hot shower if everything was full bore. I may revise my shower design by removing a head or two in each one. Still, the "full bore" scenario will not happen very often. Most likely the master shower will be the one running wide open (25-29 gpm) for extended lengths of time (15 - 20 mins).

    This is our once in a lifetime chance to build our dream home and at least one high performance shower is a must. One where the wife and I can both get in and have our own shower head to ourselves. WHere one can sit on a seat and have rain heads deluge on top of them for a while, etc.
  2. Bob999

    Bob999 In the Trades

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    Location:
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    I think I understand your dream but in my view the specs/equipment and dream still don't quite match up. The Water heaters you list will have 50 gallons of hot water immediately available and because of high recovery from high input produce another approximately 260 gallons in an hour--or about 85 gallons in 20 minutes. So your total hot water availability in 20 minutes is 50 + 85 or 135 gallons. Your single shower usage (hot plus cold) is 500 to 580 gallons in that same 20 minutes. You will not have sufficient hot water for a 20 minute shower running full bore with the single shower.

    A typical new shower head is 2.2 gpm (The Federal Energy Policy Act of 1992 required all faucet / shower fixtures made the USA to have a flow rate of no more than 2.2 GPM at 60 PSI. ). You are planning a flow more than 10 times that.

    Given that you apparently will have a well I am guessing that you will also have a septic system. Regular use of a shower that dumps 500 gallons in the septic system with a single use will have to be factored into the design of the septic system as well.
  3. nofears67

    nofears67 New Member

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    186
    Hmmm...now you have me worried...

    I revised my showers a bit and recalculated what the "full bore" scenario would be...32.5 gpm (instead of 44)...if both showers were running wide open. Again, this is WORST CASE scenario and not likely to happen very often, if at all.

    I see your point about insufficient hot water availability, and I know this isn't the Hot Water Heater forum, but what dual water heater scenario would you recommend considering the 32 gpm scenario? (Remember these tanks are going to be connected in series which I assume means the hot water production from the 2nd tank will be greater than specified since the incoming water will be "pre-heated" so to say).
    Dual 80 gal heaters?
    Dual Bradford White GX‑1‑55S6SX 55 gal heaters?

    The more likely "regular" flow scenario (under normal circumstances) would be between 7.5 - 20 gpm with both showers running.

    Oh and regarding the septic system...it will have a 1500 gal tank and respectively sized leach field (4x75' quik 4 chambers). It should not be an issue especially considering that the "full bore scenario will not happen very often and under normal use the showers would flow between 7.5 - 20 gpm combined total under normal use.
    Last edited by a moderator: Jan 29, 2010
  4. Bob999

    Bob999 In the Trades

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    448
    Location:
    Pennsylvania
    The water heaters you list have 3/4" connections. I don't think a series connection is appropriate--I believe that the connection should be parallel. Even with your reduced demand it seems to me you should be considering the 55 gallon version of the water heater--that will up your availability for the first 20 minutes to 110 + 85=195 gallons. This is probably still less than needed for 20 gpm for 20 minutes and if that is your design point then I think you will need an additional water heater (for a total of 3).

    If you have not already done so I recommend you specifically discuss the showers with the septic field designer. The showers you are planning are well outside the normal design factors used.
  5. nofears67

    nofears67 New Member

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    What about using two 100 gallon M-I-100T6SX Bradford White 100 gallon water heaters?
  6. Akpsdvan

    Akpsdvan In the Trades

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    What is the starting temp of the water coming into the house?

    Would you also have a recirculating system for the hot water?

    Another idea would be Boiler Mate water heater on the boiler that is heating your house.
  7. Bob999

    Bob999 In the Trades

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    Location:
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    That model would provide about 130 gal/unit in the first 20 minutes or about 260 gallons for 2 units. So depending on the temperature of the water in the storage tank, the temperature of your incoming water, and the temperature of the water you want in the showers these units may provide the 400 gallons of water needed for a 20 minute shower at 20 gpm. In order to make a purchasing decision you need to consider the temperature of your incoming water, the temperature you will set the heaters for, the design temperature for the shower water as well as your design point (GPM for x minutes) for water usage.

    Two water heaters with 88,000 BTU input each will be a consideration in the sizing of your propane tank.

    Given the very large hot water demands you are considering you also need to consider whether the decision of how to heat water can/should be integrated with how you heat the home. You haven't told us where this home will be located and how it will be heated but using a heating boiler for short term high hot water demand may be a viable approach in certain situations.
    Last edited: Jan 29, 2010
  8. nhmaster

    nhmaster Master Plumber

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    Seems like a huge expense and a whole lot of effort to take a shower, What exactly are you doing in there? :)
  9. nofears67

    nofears67 New Member

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    186
    I'm not sure of the temp of the incoming water, I will find out this weekend.

    Like I said many times...it is NOT likely that both showers will be operating "full bore". Since the master shower will be large enough for two (or eight...;)) people it is more likely that we'll both be in there maxing that out at one time.

    I have further refined the master shower to run 20 gpm at full bore. I would consider this worst case scenario now.

    I'm sure we'll set the tank temps at 120+ and the shower temp will normally be between 90-95.

    The propane tank will be a 500 gallon.

    I'll get back to you all with the water temp.
    Last edited by a moderator: Jan 29, 2010
  10. Bob999

    Bob999 In the Trades

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    448
    Location:
    Pennsylvania
    You must ultimately decide what the design specification is going to be. Are you going to size to provide for the one shower only and for only x minutes--or will you include some other concurrent use(s) in your design specification. The temperature of the water in the water heater makes a significant difference in the storage capacity needed. It is generally recommended that residential water heaters be set at or below 120 degrees F to reduce the risk of burns and to reduce off cycle heat loss. But increasing the temperature can allow a reduction in the size of tank in a situation like yours where you are are sizing for a short term demand. One approach is use higher storage temperatures and to use a mixing valve to temper the water as it is taken from the tank--this reduces the risk of burns.

    You seem to be saying that your design specification is 20 gpm of xx degree water for yy minutes. I suggest you check the temperature of the water in which you typically shower.

    90 to 95 degrees seems low to me in light of the fact that normal body temperature is approximately 99 degrees and most people like water to be warmer than body temperature.

    I have no experience sizing propane tanks but do know that the ability to provide an adequate flow for any given size tank is dependent upon the ambient temperature of the tank. If you live in an area with cold winters the tank will have to be larger than would be required in an area with warmer temperatures. If you end up with water heaters that have an input approaching 200,000 BTU/hr I suspect that a larger than 500 gallon tank will be required. Again you need to discuss that with the tank supplier--along with any other concurrent uses of propane you may have.
  11. nofears67

    nofears67 New Member

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    186
    Incoming water is ~ 57 degress F.
    Typical hot water shower temp is about 108 F.
  12. Akpsdvan

    Akpsdvan In the Trades

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    Why not do a few On Demand water heaters, first in last out..

    With close to 60F water and going up 50F to the 110F if you had 2 or 3 of the big ones, some how I don't think that you would run out of hot water, and be able to keep up with the flow demands that you might have.. and save room, and would not be heating water when you are not using it.
  13. nofears67

    nofears67 New Member

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    You mean tankless?
  14. Akpsdvan

    Akpsdvan In the Trades

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    Location:
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    Yes tankless... there are many brands out there, find some that can handle flows from 1gpm to 15gpm and have two , first in last out so that you have the full flow, or a balanced header.
  15. Bob999

    Bob999 In the Trades

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    448
    Location:
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    A VERY large input BTU will be required with tankless heaters. If you assume 20 gpm of 108 F water and 57 F incoming that is a temperature rise of 51 F. So the hourly BTU input required is 20 gal times 8 lbs/gal times 51 degrees times 60 minutes equals 490,000 BTU/hour. If you assume the water heater is 80% efficient then the gross input per hour is 490k/0.8 = 612,000 BTU. Getting the required propane flow to support an input of that size will require a very large propane tank.

    Three of these units (http://www.cpotanklesswaterheaters...._house_tankless/liquid_propane/2700es-lp.html) would provide approximately 20 gpm for your conditions.
    Last edited: Jan 31, 2010
  16. nofears67

    nofears67 New Member

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    186
    Bob,
    Considering the temperature rise requirements mentioned above, the typical 10 gpm and max 20 gpm hot water demands in the showers... would the two - 100 gal tank heaters be sufficient?
    Last edited by a moderator: Jan 31, 2010
  17. nhmaster

    nhmaster Master Plumber

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    3,189
    Location:
    S. Maine
    seriously, have you figured the cost of a couple of 100 gallon tanks, oversized water treatment equipment, and all the installation, piping costs etc involved in taking a shower? You are going to have close to 10 grand wrapped up here.
  18. Bob999

    Bob999 In the Trades

    Messages:
    448
    Location:
    Pennsylvania
    Sizing is done on max reqirement that must be met and I am assuming that is 20 gpm for 20 minutes. Usable storage is 80% of total or 160 gal for your assumptions.

    Two 100 gallon tank heaters could be sufficient depending on the temperature setting for the storage--it clearly would not be adequate at 120F but with higher storage temperatures could meet your requirements. If you go that route I believe that you should include mixing valves to to reduce the temperature of the supplied water.
    Last edited: Jan 31, 2010
  19. nofears67

    nofears67 New Member

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    186
    All I can say is...this is our dream, and we'll only do it once.
  20. nofears67

    nofears67 New Member

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    Bob, do you still believe that a parallel tank setup would be better than an in series design?
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