Water filter pressure decrease

[Christopher Griggs]

Hi. I am about to install a new water softener and was going to replace some 3/4 inch pipe with 1 inch and some 1/2 with 3/4. I have a three bathroom house one three piece and the other two four piece. I am on a well with 1 1/4 main in that goes down to 1" at the pressure tank and then down to 3/4 before my filters and UV light with various coupler, bypasses and shut offs throughout. I was shopping for hi flow water filters with 1" inlets and outlets and discovered that after the inlet all the ones I have looked at constrict down to 1/2 inch or even 3/8. My question is, is there any benefit to going back to 3/4 or 1" after the filters or is it pointless? Thanks for any replies .

 

[Reach4]

I was shopping for hi flow water filters with 1" inlets and outlets and discovered that after the inlet all the ones I have looked at constrict down to 1/2 inch or even 3/8.

There are ones that go in 1 inch and come out 1 inch.

What have you been looking at?

As to increasing pipe size, it is not pointless, but not as good as having a filter that is not greatly reducing the diameter.

 

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[Christopher Griggs]

Everything is closed down where I live so I have spent most of the day looking online. There are lots with a 1" in and a 1" out but that is just the plumbing size, if you look in where the fixture goes the actual feed hole to the filter is significantly smaller. Could you tell me the names of the ones that are a true 1"?

 

[Christopher Griggs]

And is it pointless to go back to a larger line after?

 

[Reach4]

I am familiar with the Pentair Big Blue housing. I like the 4.5x20 size.

I cannot say the path is 1 inch the whole way. https://www.pentair.com/en-us/produ...ters-housings/big_blue_heavy_duty_series.html says "The 1-1/2" internal port allows a greater volume of liquid to pass through the HFPP cap more rapidly." I am not going to take one apart to verify that myself.

I am guessing you are referring to cartridge filters. There are other types of whole-house filters. What are you trying to filter out? Sediment in city water? Sand and pebbles in well water? Iron?

Still not pointless to increase pipe size. Pressure drops add.

Using a whole house filter with 1 inch input and a 3/8 inch output ID seems pretty lame. Care to name that filter?

 

[Christopher Griggs]

There are ones that go in 1 inch and come out 1 inch.

What have you been looking at?

As to increasing pipe size, it is not pointless, but not as good as having a filter that is not greatly reducing the diameter.

I have been looking on line because everything where I live is closed down. There are lots with a 1" out and a 1" in but that is the size of the plumbing fixture it accepts, if you look past the initial openings the hole that feeds to the filter constricts significantly. Could you tell me the names of the ones that are a true 1" inch? Thanks

 

[Aaroninnh]

Not trying to be insulting, but you're worried about stuff that you don't need to worry about. A There is a very small amount of pipeway in these filter housing. The water comes in and it immediately dumps out into the filter housing. The water works its way through the housing and into the outside of the filter, through the filter, then rides up the center of the filter, which is about 1.125" in diameter. When it hits the top of the filter is has maybe a couple inches of pipe before it then hits the outlet.

The filter itself is a bigger flow issue than the small waterways in the housing, so make sure you are going with a big filter with lots of surface area so it can move a lot of water. A 20" big blue with 3/4" inlet/outlet is going to be better for you than a 10" big blue with 1" inlet/outlet.

I have a 20" big blue fed with 1" PEX in and out and move north of 12GPM all day long through it. I'd do more but its all my pump can put out.

 

[Christopher Griggs]

I am familiar with the Pentair Big Blue housing. I like the 4.5x20 size.

I cannot say the path is 1 inch the whole way. https://www.pentair.com/en-us/produ...ters-housings/big_blue_heavy_duty_series.html says "The 1-1/2" internal port allows a greater volume of liquid to pass through the HFPP cap more rapidly." I am not going to take one apart to verify that myself.

I am guessing you are referring to cartridge filters. There are other types of whole-house filters. What are you trying to filter out? Sediment in city water? Sand and pebbles in well water? Iron?

Still not pointless to increase pipe size. Pressure drops add.

Using a whole house filter with 1 inch input and a 3/8 inch output ID seems pretty lame. Care to name that filter?

I read multiple reviews on many filters over the past few hours stating that various makes and models of filters accept one inch plumbing but go down to 3/8 after the inlet, so what would be the use in using 1"/ As I said in my initial question I am on a well. I currently have a UV/ two cartridge system that works fine, but I was going to replace it with a larger capacity one while I was installing a new water softener

 

[Christopher Griggs]

Not trying to be insulting, but you're worried about stuff that you don't need to worry about. A There is a very small amount of pipeway in these filter housing. The water comes in and it immediately dumps out into the filter housing. The water works its way through the housing and into the outside of the filter, through the filter, then rides up the center of the filter, which is about 1.125" in diameter. When it hits the top of the filter is has maybe a couple inches of pipe before it then hits the outlet.

The filter itself is a bigger flow issue than the small waterways in the housing, so make sure you are going with a big filter with lots of surface area so it can move a lot of water. A 20" big blue with 3/4" inlet/outlet is going to be better for you than a 10" big blue with 1" inlet/outlet.

I have a 20" big blue fed with 1" PEX in and out and move north of 12GPM all day long through it. I'd do more but its all my pump can put out.

Thanks. So you are saying that the water constricting down to 3/8 from one inch does nout affect water flow?

 

[Aaroninnh]

Thanks. So you are saying that the water constricting down to 3/8 from one inch does nout affect water flow?

Correct. The filter housing is a very very very small piece of the pie here. Water will speed up going through the smaller opening and slow down as it expands on the other end. The flow is the same. What it does is create a little friction. That friction can cause pressure loss if it went on for many many feet, but it is an inch long in this case. Maybe less.

The filter is a far bigger problem with flow restriction than the water pathways within the dinky little housing.

What you are describing is very common. Many shutoff valves are smaller than the pipe "standard port" versus "full port". Pex fittings all are far smaller than the pipe they are for. This is normal.

 

[Christopher Griggs]

Correct. The filter housing is a very very very small piece of the pie here. Water will speed up going through the smaller opening and slow down as it expands on the other end. The flow is the same. What it does is create a little friction. That friction can cause pressure loss if it went on for many many feet, but it is an inch long in this case. Maybe less.

The filter is a far bigger problem with flow restriction than the water pathways within the dinky little housing.

Ok Thanks. Seems wrong , but thanks for the answer. So what you are saying is that if I took 2 5 gallon buckets and and drilled a 1" hole in one and a 3/8 hole in the other they would empty at the same pace?

 

[Aaroninnh]

Ok Thanks. Seems wrong , but thanks for the answer. So what you are saying is that if I took 2 5 gallon buckets and and drilled a 1" hole in one and a 3/8 hole in the other they would empty at the same pace?

Thats a false test and has very little to do with your original question, and my job isn't to convince you as you've obviously convinced yourself that you require a 1" full port filter head for your house.

Look up bernoulli's principle.

Think of it this way. You turn on a hose and water comes out. You fill a bucket.

You then put a sprayer on the end of the hose and put it on stream mode, what happens? The water shoots out farther and harder. Why? It speeds up going through the small hole. The water tries to keep the same flow and it has to speed up to do it.

Im not saying pipe size doesn't matter...it does, what I am saying is this issue you are concerned about isn't a concern for the small distance it is constrained in the filter head. If this was 20 feet of 3/8 inch pipe it would be a different story. A couple inches? Nope.

 

[Reach4]

Thanks. So you are saying that the water constricting down to 3/8 from one inch does nout affect water flow?

NO.

 

[Reach4]

NO. Bye.

 

[Jeff H Young]

christopher griggs. plumb it how you want but plumbing a house in 3/8 because thats the size of hole in the filter isnt a good idea . increasing size on pipes only helps if you need it exaggerating and putting a way bigger or way smaller pipe would be pointless but if you feel your not getting enough volume concider it

 

[Christopher Griggs]

All I was asking was would it be pointless to go back up to 3/4 .

 

[Aaroninnh]

All I was asking was would it be pointless to go back up to 3/4 .

No, not pointless, and exactly what you should do.