Above ground pool pump questions
I am in the process of selecting a new pool pump to replace my old one that just went out. I have a 12 x 24 oval pool 7600 gal. The pump motor I had was an AO Smith BN35 Single speed 1.5HP and it is mated to a Sand dollar pump and it has an SD-40 Sand Dollar 19" sand filter. I am thinking of replacing it with a 2 speed AO Smith BN50 which is 1.5HP on high and .25 HP on low. Is there any reason this wouldn't work? Is .25HP enough to force water thru the filter. It is a 3 FT long inlet and return hose is 6 Ft in length, both 1.5" diameter
The filter has a 40 GPM design flow rate. Could I go even less and get the BN37 which is a 1 HP high and .12HP low? Thanks
Re: Above ground pool pump questions
Quote:
Originally Posted by
khager
I am in the process of selecting a new pool pump to replace my old one that just went out. I have a 12 x 24 oval pool 7600 gal. The pump motor I had was an AO Smith BN35 Single speed 1.5HP and it is mated to a Sand dollar pump and it has an SD-40 Sand Dollar 19" sand filter. I am thinking of replacing it with a 2 speed AO Smith BN50 which is 1.5HP on high and .25 HP on low. Is there any reason this wouldn't work? Is .25HP enough to force water thru the filter. It is a 3 FT long inlet and return hose is 6 Ft in length, both 1.5" diameter
The filter has a 40 GPM design flow rate. Could I go even less and get the BN37 which is a 1 HP high and .12HP low? Thanks
1.5 HP on a 7600 gallon pool???? Is it a giant hot tub that you need massage jets?? That is 'way, 'WAY too big for such a small pool.
You don't need anything bigger than a .75 hp MAXIMUM and a .5 hp would serve you beautifully and save you a bazillion $$$ in electricity.
I suggest you go to the sister site, poolsolutions.com and read the tips, especially the old gem "The BIGGER pump scam!" #83 under "more tips". Notice that in Ben's example, the 18,000 gallon pool is using a .75 hp pump.
Here is the text in Ben's own words:
Quote:
Men are sometimes really into how big their car's engine is. Or, their boat. Or, their biceps. Or, their whatever. Even some women reportedly have been caught up in the 'bigger is better' excitement.
But, as has been often observed, it's not size that counts, but how you get the job done.
This is especially true with swimming pool pumps. Flow genuinely affects how well your pool operates. But the only thing pump horsepower always affects is how large your electric bill is! What really counts is not how BIG the pump is, but how well matched it is to the rest of the pool.
A typically (not optimally) designed 18,000 gallon pool with 1.5" pipes and a 3/4 HP pump will filter about 18,000 gallons every 8 hours -- and cost about $40 per month to operate.
The SAME exact swimming pool, with a 1.5 HP oversized pool pump, sold and installed by an gung-ho dealer or salesman, will filter about 24,000 gallons in 8 hours -- and cost about $80 per month. Doubling the HP, in this case, only increases filtration by 33%. But doubling the HP does double your electric bill. Ironically, it will also worsen filtration, since the filter will be 'overdriven'! In fact, many problems with sand filters (and the sand in them) result from matching small sand filters with big pool pumps.
So the next time a pool salesman tells you he'll put a BIGGER pump on if you sign now, ignore him, and ask how many gallons per minute flow he guarantees the pool to deliver -- and whether the filter is rated for that flow.
Re: Above ground pool pump questions
I have a 1/2 hp on a 13,000 gallon pool and it is quite adequate. Just FYI.
