Advice for new setting up new UV system

[BobJackson]

Hi everyone,

If anyone has the time to read through this and can offer any advice or recommendations it would be very helpful, and thank you in advance for any info on this.

We've just bought a UV water filter system to run our well water through. Actually the term "well" is generous. We bought a house late last year and our water comes from a slow spring that empties into an extremely shallow cement basin (another project in the next couple years), which is then pumped into the basement into a holding tank. The "well" is not really sealed and as it is now can't be. There is evidence of mice around the well (nothing serious), and also the water may sit in the indoor holding tank for a few days depending on our water usage. For these reasons we just want the peace of mind of having clean tap water.

The system we bought has a pre-filter and then the UV canister. Luckily the shop that came with the house had some random copper pipe and fittings, so I bought a solder and flux kit and practiced on that already, and feel comfortable with the actual process. My main questions are around pipe size and valve differences.

For starters, our indoor water holding tank runs through a very short 1 inch PVC pipe into a jet pump. The pump has a 1/2" PEX line coming out that splits in two and goes to the hot water tank and a network of pipes for the cold water. I think the PEX is new to the more recent basement and addition to the house, so I'm guessing all the plumbing in the house is a mix of PEX and copper. The UV system will go in right after the jet pump before the line splits. The manual with the UV system only mentions 3/4" pipes to connect everything, but also says "you may need different fittings if your pipe size is different". The whole UV system will be sandwiched in between 1/2" PEX lines, so I have no existing copper to match sizes with (not that it would really matter). The other thing the manual mentions a couple times is ball valves for the various shutoffs and bypass line. But, in the diagrams it shows the typical round-knob valves that basically every hose faucet has on the side of a house. The only "ball-valve" options I can see at the hardware store are the red-handle 1/4 swing type. I'm assuming the actual look of the handle (round vs. straight) doesn't matter, and it's just that my local place doesn't have round-handled ball valves? The only round-knob types they have are compression valves, which as I understand use a rubber gasket to press down inside and stop the water. I've done some searching and see people saying each is better. Ball valves can't be fixed, but last longer. Compression valves can be fixed, but might not last as long. The one other thing with these valves is that I can get them with threaded ends or just flat ends for soldering. When I went to buy these I figured it would be more straight forward (I don't have any plumbing experience). What is the purpose of a threaded valve if all copper pipe has no threads and would need a threaded end soldered on, just to then be taped to a threaded valve? Wouldn't it be stronger to just solder the pipe directly to the valve? The one other option I was seeing with valves (only the compression type if I remember correctly) is that there were options with a small drain, which kind of resembled a burst valve. I don't think I would ever need this (I'm already going to be connecting a drain below the UV filter for when the bulb needs replacing), but they don't have enough valves without this drain. Is it a bad idea to buy a valve with a potential extra failure point if I'll never use the drain?

Finally, the main two questions I have are about the copper pipe size used to connect all the water filter components, and the type of valves to use. If the PEX lines coming into, and running out of the filter system are 1/2", is there any benefit to using 3/4" copper on the actual UV system? I've read in similar situations (minus the UV filter) many people say no, because the input line is already 1/2". I've seen people say going up in pipe size can lower water pressure too. I'm not really concerned about that though because the line drops back down to 1/2" right after the filter system. My thought is, could 3/4" pipes within the filter system slightly drop the pressure within the system, causing the water to move slightly slower past the UV lamp before hitting the smaller 1/2" PEX and then being forced back to a higher pressure? This is my uneducated guess. My other thought is that the jet pump pushes so hard that the 3/4" lines would be pressurized just the same as the output 1/2" PEX, because the PEX would create some resistance where the 3/4" ends and cause the small amount of 3/4" copper to build up the same pressure as the 1/2" PEX.

For the valves, should I spend the extra $30-$40 and get the 1/4 turn straight-handle ball-valves, or just go with the cheaper compression valves? It's not so much the price I'm concerned about, but more the physical size of the valve. The valves will be seldom used, and the round-handle compression valves just don't have those the big handles sticking out. I suppose the threat of them catching on something is minimal though. The other thing with the valves (more so than the copper elbows) is the price difference between 1/2" and 3/4". My decision on the final pipe size will really affect the cost of the valves.

Thank you so much if you read all that. I'm grateful for any advice on this setup.

 

[havasu]

I have a friend who is one of the leading designers and developers of UV water filtration and if done right, is a great way to reduce/eliminate chlorine and other nasty chemicals. He explained that water volume and pressure are often overlooked and is the leading cause of failures. Basically, the more volume you have, the more exposure of UV light is needed. Most of his systems use 8' UV tubes surrounding a small clear tubing for maximum penetration. I wish you good luck, but please understand if not done correctly, you will be wasting lots of time and effort.

 

[breplum]

Never use anything other than quarter turn lever handle ball valves by major manufacturers. Us plumbers know that cheap imports are not worth it, but there are very good imports like Matco that can be o.k.
I am not going to comment on flow and your UV, that is not in my realm of experience for domestic drinking water.
Beware, that if not sized and installed properly, you potentially have serious health risks.
I recommend finding a local professional with a good reputation who knows what they are doing.

 

[BobJackson]

Thank you both for the info. The kit is from Rainfresh and is more or less designed to be installed DIY by anyone with some basic experience. I haven't measured my water pressure, but I did measure GPM. The UV kit is rated at 8 GPM, and even my bathtub which has the highest flow fills at 6 GPM (on straight cold, so overall draw would be less than 6 GPM from the UV system with regular filling that uses hot water too). Based on their max flow rating and guaranteeing disinfection, and that my maximum GPM is well below their maximum, I'm not concerned about contamination. I still plan on having the water tested after installing the system though. Also, we've been living here almost a year and only filtering drinking water, not bathing water, and have had no issues.

My question about the valves was answered and I greatly appreciate that. The 1/4 turn handles are what I was leaning toward, as they were the ball valves verbally mentioned in the manual regardless of what images were used in the manual. I'll look into the brands that are available locally too.

The only reason I asked about using 1/2" vs 3/4" copper within the pieces of the UV system was more a general water pressure question and I guess not unique to the UV system (although the system could play a part in the pressure, it's not really something anyone could comment on without knowing the exact design of the system). In my situation, if there was no filter or UV system involved, do you think building a small section of 3/4" copper pipe (about 4 feet total, with 3 or 4 90 degree bends) in between a 1/2" input and 1/2" output would make any difference to the final water pressure coming out of the taps?

I guess what I' saying is I'm not really concerned about the sanitation part of this whole thing. I trust the guarantee on the system, and if my water tests come back no good then I'll go from there. My main concern is how the pipe size I choose to connect everything within the system could affect the final water pressure given the 1/2" lines surrounding the system.

Thank you all again for any further info.

 

[Solid]

Just a quick question for you. You said the discharge from your jet pump is 1/2” PEX. Can you post a picture of that?

 

[BobJackson]

Sure thing. It's definitely not designed for that size, and I don't really know why they went with such a small line before the water even got to the hot water tank. In the picture, after the line goes out of view it goes up to a T on the ceiling, with one side going to the hot water tank and the other side splitting again before it goes into the ceiling. There's a shutoff before the first T as well.

Now that I'm saying all this, maybe it will be worth the extra cost to use 3/4" copper on the UV system, and go to a 3/4" PEX out of the pump and after the UV system until the hot water tank. The manual for the UV system recommended 3/4" anyways.

 

[Stout Mechanical]

Your over complicating everything, if your entire house is run on 1/2” then get yourself a couple 3/4 x 1/2 reducers and reduce down at the inlet and outlet of the light and pre filter. They are tubes with bulbs in them. They do not create a pressure drop. There is also no reason to use copper over any other pipe type. From your post I wouldn't suggest you use copper unless you have a backup plan. Make your life easy and use pex or cpvc.

As mentioned above you should be more concerned with the quality of your incoming water, the light manufacture has specific parameters for the incoming water quality to achieve the desired results. If your installing any type of filtration equipment with out testing the water first you are only guessing and hoping you will have something functional when complete.

 

[fixitron]

To begin, I don't see any mention of a pressure tank. The pipe to the pressure tank should be 3/4" (or larger). The smaller piping will make the pump run much longer to refill the tank, wasting electricity and shortening its life, never mind trying to keep up with too much demand for the system at 1/2" piping throughout.

A 1/2" pipe can carry up to about 14 GPM at 50-60 PSI, but the longer the piping to a fixture, the more the pressure and velocity will decrease, which results in lower flow rate. That size of pipe can only supply water at a reasonable pressure to a few fixtures at the same time. A tub spout flow rate will be maybe 3 times the rate of a lav faucet or kitchen faucet, so running the tub at the same time as maybe the laundry may result in lower flow to both.
Increasing the size to 3/4" from the pump to the first tee will allow more water to flow simultaneously through both 1/2" pipes off of the tee. Right now, the flow through the pipes leaving the tee will each be less than what can flow through the pipe feeding the tee. In other words, I suggest changing to 3/4" pipe from the pump to at least the pressure tank and water heater.

Think about the water flowing through a pipe. The smaller the pipe, the more surface area to volume ratio and the more friction of the water along the pipe walls. Every fitting (tee, elbow, valve, etc.) provides even more friction as well as turbulence as it rounds a corner or hits an obstruction along the walls. If the pipe is going up, the water also loses pressure as the height increases, because of gravity.

 

[Solid]

Now that I'm saying all this, maybe it will be worth the extra cost to use 3/4" copper on the UV system, and go to a 3/4" PEX out of the pump and after the UV system until the hot water tank. The manual for the UV system recommended 3/4" anyways.

This is where I was headed with my question. I’d get rid of the 1/2” reducer out of the jet pump and use 3/4” pex. I’m guessing you don’t have any pex tools, right? Your going to have to select a pex type: cold expansion or crimp. The tools to make the connections aren’t cheap, but they are easier than sweating copper. You could check eBay, but I can’t point you to anything specific. There’s also Sharkbite fittings that could work, they can be expensive as well. If I were you, I’d just call a local plumber to do it. You have all the components, and it would take them no time to hook this up. Of course this is assuming whatever requirements the UV system has are met.

 

[BobJackson]

I really appreciate all the input. We don't have a pressure tank; it's just on-demand pressure from a jet pump in the basement that moves water from a holding tank in the basement. Something I want to get done in the next couple years is getting a larger holding tank and burying it outside, with a submersible pump, for multiple reasons. That job definitely won't be DIY.

I don't have any tools for PEX yet, just copper. I was already planning on buying a PEX crimper though after we decided to get the UV system (that's the connection used on all the PEX in the house). They're not too expensive, and it's one of those things I'll have that could come in handy in the future, for me or friends/family.

Unless I end up with a plumbing project that involves large portions of my house, I want to be able to do these smaller things myself. I'm sure a pro would get the job done much faster, but it's just a skill I'd like to build up so that I'm less reliant on other people for small fixes.

The handy thing with installing this UV system is that I can get 90% of the work done before even shutting off the water, so if it takes me longer than I plan it's no big deal. The whole system and the connections will be anchored to plywood that I'll then mount to the wall. After that it's just connecting the single PEX input and output.

Again thank you for the advice and recommendations on taps and line sizes. Going to 3/4" right out of the pump and also to the hot water makes the job a little bigger, but it's better to just do it right (or at least more right) than it is now. I never understood why they used so many step-downs in the system. The water is pumped from the well into the basement through a 1 inch line, then drops to 3/4" for a sediment filter, but then leaves the filter as 1/2". Anyways, that's all stuff that will be changed down the road when we can get to the big holding tank project.

 

[fixitron]

Some food for thought-
There are 3 ways to connect PEX tubing to fittings- crimp ring, compression ring and expansion ring. I use the expansion ring method for two reasons. The first two methods use fittings that effectively reduce the size of the pipe. With the expansion fitting, the inside diameter of the fitting is the same as the inside diameter of the pipe. With the first two methods, you have to connect the fitting and then get the tool in the right position, which can be awkward and difficult in some situations. With the expansion fittings, you can expand the pipe end and then, quickly, reach out and push it on to a fitting.

There are 3 types of Pex- A, B and C. Each is made a different way and each has different properties. Pex-A is generally preferred.

If your water system does not have a pressure tank, then the shallow well jet pump has to kick on even when you are only drawing a glass of water. That will result in a rather short life for the pump. Since water expands when heated, you must have an expansion tank on the hot water side, or else your PT relief valve on the water heater would be lifting. That expansion tank would also be doing the work of a pressure tank (basically they are both the same), but at a much smaller volume.
So, does your pump run just about every time you draw any water?

 

[BobJackson]

The main reason I was going to go with crimps on the PEX was cost, and it's what the house already has. I understand the tool needed for the expansion rings is more expensive, although I haven't looked into the actual cost for it. I hadn't looked much into the PEX tubing, other than some isn't rated for potable water. I planned on doing some research before buying any PEX parts, but your info on that lets me know where to start.

I wasn't aware of the expansion tank for the hot water. That's something I will definitely look into. Depending on cost I may just look at going the pressure tank route. I grew up in a house with a pressure tank for the well water, and was totally new to jet pumps when we bought this house. At first I did think of the constant on/off of the pump, and the wear that puts on it. Yes, it does turn on if you run anything more than a quick trickle from the tap. I had thought of replacing it with a pressure tank when it died. But, the potential issue with the hot water tank was something I was unaware of. I'll have to look into what I want to do with that whole situation, and maybe make the change to a pressure tank before the jet pump dies. I don't see the point in buying an expansion tank if I plan on moving to a pressure tank anyways (by your comment it sounds like a hot water expansion tank isn't necessary if I have a pressure tank instead of a jet pump?).

Our indoor holding tank has floats that trigger the other jet pump in the well house (very shallow well) to turn on/off when the indoor tank runs low. The well pump runs for about 12 minutes to fill the indoor tank, which only happens maybe once a day on average. But yes, the indoor jet pump gets a ton of on/off use.

 

[fixitron]

The other kind of PEX is for boiler water. It has an oxygen barrier. I think that it some brands can be used for potable water, but you will need to check the specs.
Yes on the last question. If you have a pressure tank for your water pump, you do not need a separate expansion tank for your hot water, since all of the plumbing is connected and there are (typically) NO check valves between the water heater and pressure tank.