we have a 5 ton dual air heat pump. we have a well for irrigation that i tied into i want to add a pump to the well with the geo unit being the only use for the pump. we need around 15 GPM. its a 2 in well water level is around 15' and the well is 70' deep im in central fl. my question is how to set up the pump and what pump to use, should i have a pressure tank, or should i just use the pump thanks guys
Definitely use a pressure tank, I've seen people try to get away without and there is a whole lot o' banging going on which is really hard on stuff even with slow acting control valves. However you could probably get away with quite a small tank (5gal) as it is just one thing on the pump running at full capacity when it's on. I like Grundfos pumps myself, they make some nice jet pumps that would work in your scenario, take the well specs to whoever is your local dealer is and they should be able to size it for you. It's too bad you have such a small diameter well or you could have used a variable speed submersible which are more efficient.
A 2 inch well with a 15' static water table, will have to have a specific capacity of 1 gallon per foot to work. I would hazzard a guess that you will need at least a 3/4 hp to pull that much water at lets say 20' pumping level, a 1hp would prolly do the job better. The other key here is that you do not need alot of pressure out the other side, just flow. That may allow you to reduce your hp some but you need to check each pump manufacturers chart to be sure. The charts are set up to read so many gallons at x pressure, if the pumping level is x. Also a pressure tank only provides a shock absorber for the switch, and instant gratification. I have set jet pumps up to be turned on and off via the compressor contactor, YMMV. Eric
Usually the manufacturers spec 1.5 gpm/ton if EWT is above 50F, below 50F they want 2 gpm/ton. 2 valve setup should allow you 5 gpm and 7.5 gpm flow, so your pumping requirements should be less than you think. Look at variable speed pumps for efficiency.
Technical note, variable speed pumps that operate by pulling a vacum are not effecient at 15' of lift or in expensive to purchase. Eric
Well, they work great for us in multiple heatpump applications and multi stage compressors. They are more expensive, but save you the second valve circuit and set up properly save you a ton of money. This whole system is all done by a single variable speed pump. I am pretty intrigued by them. Temperature and Energy logging by: Web Energy Logger
Just a clarification. We are talking about a centrifigal jet pump for pulling water out of a well for supply, not a circulator pump for the building loop. Eric
I agree with the above statement. with the amount of time the water pump will have to run to satisfy a geothermal system, I would be interested in pricing out a 4" supply well. What do you plan on doing with the discharge water, another 2"well? I would be cautious of your expectations of a 2" well accepting 15 gpm return. I am partial to the Grundfos SQE line of pumps too (zacmobile), but they start in 3" diameter.
my water temp is 73*F the manufacturer suggested 15 GPM. i have temp and pressure gauges on inlet and outlet of unit is there a way to Taylor the flow to the readings on the gauges. for a more accurate adjustment? on a side note its getting cold out so im using the heat on the 2 TON FHP geo unit here at my house i must be getting a real high COP with my loop temp at 75*F. love my geothermal unit and its running on 4kw worth of Solar panels. thanks again
Do you have a closed loop or a pump and dump? Or was your original question about your irrigation well to tie into your closed loops? Too many questions, " not enough space bags". Eric
the system in question is pump and dump which is at my bosses house, the other system is at my house and is a closed loop disregard my system. i should be getting a 3/4 HP pump today ill let you know how she goes
What brand and model are you using? Would like to see the manufacturers literature requiring 15 gpm for open loop with 75F EWT. Would be very uneconomical and a waste to pump up that much water.
Account Suspended i met with the owner of the company and he said to run 15 gpm so i didnot think much about it after that
