Upsizing from 1/2 to 3/4 after water filter

[mrmills]

Hi all. I am looking for some guidance or suggestions.

I am getting ready to install an Aquasana whole house water filter system. The main line in my house is 3/4 inch, and then it branches off to the boiler, bathrooms, etc with 1/2 copper. I'm obviously going to cut into the 3/4 line to install the filter system, but all the fittings that came with the system are 1/2 ID.

My concern is I will experience problems (like pressure?) that going from the 1/2 filter lines back to the 3/4 main line may cause? Aquasana says the filters cause no perceivable loss in pressure. It just seems wrong going from 1/2 to 3/4. Is my concern warranted?

Any help or guidance is much appreciated. Thank you!

 

[Twowaxhack]

Your filter should be 3/4 minimum for a 3/4” line.

 

[MicEd69]

Yes, there be an impact. Will you be able to notice it? Probably not. The biggest issue is to make sure the unit you have will supply the proper flowrate for your entire house.

 

[Twowaxhack]

Volume will suffer and flow velocity will increase through the filter. Dynamic pressure will drop but static pressure will be the same.

 

[MicEd69]

As I said, "The biggest issue is to make sure the unit you have will supply the proper flowrate for your entire house." If the filter is sized for the house's flow rate, the flow through the filter will not increase over the flow rate specs of the filter. The dynamic pressure will be lower, as I indicated, but will not be noticeable.

 

[Twowaxhack]

A 1/2” inlet and outlet filter head can’t provide the flow rate for a home at the recommended velocity.

It’s just not possible. You need a bigger filter head.

 

[MicEd69]

Again Twowaxhack, I'm not arguing with you. I said, "The biggest issue is to make sure the unit you have will supply the proper flowrate for your entire house."

If the unit memills has indicates it can provide the flowrate his house requires, and the connections are 1/2", then by definition the flow rate through the filter head and the filter media will not be above the recommended velocity for that unit. And the pressure drop over a couple of feet of 1/2" pipe will be negligible to connect that filter in the 3/4" main line.

But I agree 1000% that he needs to verify his house's flowrate requirements, hence my statement, "The biggest issue is to make sure the unit you have will supply the proper flowrate for your entire house."

Perhaps he is single and has a one bedroom house?

 

[Twowaxhack]

Yeah, a 1/2” filter head is too small for any home water supply. Even for a dorm room.

3/4” or bigger, for a typical home I would choose 1”. This would not only be large enough it would further minimize the restriction through the filter head.

1/2” filters are what I use under kitchen sinks. Sometimes I use 3/4 under sinks, minimize any pressure loss.

 

[MicEd69]

Yep, the biggest issue is to make sure the unit you have will supply the proper flowrate for whatever the usage will be.

 

[mrmills]

Thank you all for your input. I just noticed the ball valves supplied have 3/4 on the side, but measuring the ID male end of the valve, its closer to 1/2" and matches up to 3/4 PEX. I'm finding that 3/4 PEX is .681 ID, and 3/4 copper is .785 ID. How come there is so much difference in size?

These units say they can do up to 3,000 sq ft home. Mines just a 1,200 single floor ranch with me and my wife. Don't have too much demand.

 

[Twowaxhack]

Thank you all for your input. I just noticed the ball valves supplied have 3/4 on the side, but measuring the ID male end of the valve, its closer to 1/2" and matches up to 3/4 PEX. I'm finding that 3/4 PEX is .681 ID, and 3/4 copper is .785 ID. How come there is so much difference in size?

These units say they can do up to 3,000 sq ft home. Mines just a 1,200 single floor ranch with me and my wife. Don't have too much demand.

Install it and if it works great. If it doesn’t, get the next size up.

 

[MicEd69]

Thank you all for your input. I just noticed the ball valves supplied have 3/4 on the side, but measuring the ID male end of the valve, its closer to 1/2" and matches up to 3/4 PEX. I'm finding that 3/4 PEX is .681 ID, and 3/4 copper is .785 ID. How come there is so much difference in size?

These units say they can do up to 3,000 sq ft home. Mines just a 1,200 single floor ranch with me and my wife. Don't have too much demand.

It's interesting that the filter is sized by house square footage instead of the number of fixture units, or number of people, like a septic system. In any case, it appears that the Aquasana whole house water filter system you have will work according to their specifications.

Good luck and happy plumbing to you.

 

[Twowaxhack]

From what I remember whole house usually allows around 10-12gpm of flow.

I don’t use a ton of filters though. Most people don’t use tap water to drink around here. They use it for ice and coffee and that’s what I’m usually filtering. I really like those AO smith sediment filter heads with the metal inserts for the inlet and outlet. For $25 you can’t beat it. Takes common filters too.

 

[RS]

I have always installed filters like an OMNIFilter just ahead of our softener, it makes the softener more trouble -free. The housing is 3/4 pipe, rated at 10 gpm, but the 5 micron elements I use are only rated at 5 gpm. There are just the 2 of us in a house with 2 bathrooms, and it works just fine. When I sense a lower flowrate it's time to change the element, but they last 4-6 months. When you see what the used element looks like you would never want to go without a filter!