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[schoppy]

From the OWB to the house is about 75 feet (1" pex). I used all push fittings which I will probably be replacing as some of them leaked and I don't want that again. One 90 elbow on the supply just inside the house wall before the strainer and pump then 90's at the 10 plate and the air coil with one more 90 on the return line at the house wall again. The pump is a B&G NRF-36, 3 speed. Is my 1" pex going to be big enough for a 10 plate DHW, a 20 plate for the in-floor and the water to air coil on the furnace? The shed is 175' and heats a 40 plate water to water for my in-floor (this had a pretty large delta-t). Thanks.

[RSI]

The 10 plate is more restrictive that all the pipe in the system.
Are you just adding the floor heat and the rest is all existing?

Will the floor heat be heating an area that was heated before with forced air or somewhere that was previously not heated by the boiler?

[mlappin]

When you say 90’s I take it you’re referring to the pex fitting 90’s? Short and sharp bend like a pipe elbow?

Like RSI pointed out, the 10 plate adds a LOT of restriction and the short nineties add more.

In the shop setup I used long radius copper elbows, takes up more room but a lot less retriction.

[schoppy]

The more I read the more I learn. I would have thought the more plates the more restrictive but you are saying just the opposite? The floor heated area is normally heated by a 46,000 BTUH water to water geothermal system, it would be additional load on the owb if I added it. Right now all of my fittings are 1" push fittings including the 90 degree elbows. Would 1x1x3/4 monoflow tees work for the 10 plate and 20 plate if I added the 20 plate in? Do you normally do the first in last out for the piping of the monoflow tees? Or should I look at changing out the 10 plate? RSI, I see you are from Wisconsin also, I'm just north of Portage. Thanks guys.

[mlappin]

Once you reach a certain size in your plate exchanger’s they go up to one inch fittings, go with even more plates and they go up to 1 1/4” fittings. Most if not all of 10 and 20 plates I’ve seen listed only have 3/4” ports.

[RSI]

All the plates are in parallel so the more you add, the less restriction. The port size has little to do with it. A 3/4" threaded fitting will be larger inside than a 1" pex fitting.
Most 5x12 heat exchangers have a minimum of 1" threaded but some 20 plates have 3/4" on the side for the DHW so less adapters are needed.

Since you are adding more heat load, I would go with two 30 plates in series. It will keep head pressure to a minimum and should increase the flow by a couple GPM over what you have now.

If you went with two 20 plates it might be ok but bigger is better on heat exchangers.

If you want to try another brand of push fittings, I have a couple Copperhead brand elbows that I ordered for someone and then they decided to use crimp instead.

I am in Columbia County too.

[mlappin]

All the plates are in parallel so the more you add, the less restriction. The port size has little to do with it. A 3/4" threaded fitting will be larger inside than a 1" pex fitting.
Most 5x12 heat exchangers have a minimum of 1" threaded but some 20 plates have 3/4" on the side for the DHW so less adapters are needed.

Since you are adding more heat load, I would go with two 30 plates in series. It will keep head pressure to a minimum and should increase the flow by a couple GPM over what you have now.

If you went with two 20 plates it might be ok but bigger is better on heat exchangers.

If you want to try another brand of push fittings, I have a couple Copperhead brand elbows that I ordered for someone and then they decided to use crimp instead.

I am in Columbia County too.

Depends on what your line sizes are though, I went with the Logstor for more flow, I still need to work on the stuff in the house, but in the shop it’s all a minimum of 1” copper so I could get the flow without having to use a higher capacity pump.

Be a shame to install Logstor then cut the flow down with a 10 plate that only had 3/4” ports.

[schoppy]

My 10 plate does have 1" ports. Replacing my 1" pex lines is not an option for me, not going through that again as I buried my lines 6ft deep and ran a potable water line at the same time. I was looking at changing my push elbows to long radius 1" copper with sweat to crimp adapters. We'll see what Shark Bite says about their fittings leaking. Their literature says they are rated for 200 psi and 200 F and I know my boiler never saw 200 F.

RSI when you say two 30 plates in series do you mean using monoflow tees or just piped in series because I would still have my 22x25 water to air coil down stream of the two 30 plates? I looked up Copperhead fittings and they look good but reluctant on push fittings now. How does supply temp drop across a 10 plate versus 30 plate compare for the same load? Are you a dealer in Columbia county?

Has anyone ever measured the I.D. difference between the stiffener for 1" push fittings versus 1" crimp? Wondering how flow compares between the two?   

[RSI]

I never use Monoflow tees so I am not sure how well they work. I meant just in series. You may want to put bypasses around each heat exchanger so you can isolate them if necessary.

Another possible way that might work better is to put the floor heat exchanger and water to air heat exchanger in parallel after the DHW heat exchanger. It depends on the piping and heat load on them if this would be better.

If you had Sharkbite brand fittings, I wouldn't bother trying any other brand. What brand is your pex? Yes, I am a boiler dealer in Columbia County.

The size of the stiffener in the sharkbite fittings will be close to the same as the crimp fittings. It may be slightly larger but not much.

[schoppy]

My piping is Rehau 1" PEXa (red) oxygen barrier running from the boiler to the house and shed. It is Rehau 1" PEXa non-oxygen barrier (white) in the house and shed. It is my understanding that 1" PEX a,b or c are all the same dimensions but use different processes to cross-link the plastic.   

[RSI]

Since you have PEXa, you can use the expansion type fittings. They do require special tools but the Rehau Everloc fittings are much better than anything else. The Wirsbo style expansion can also be used but they aren't as good as Everloc but do have the larger inside diameter. I saw Menards is now selling the Wirsbo style and the tools are cheaper than for everloc.

Regular crimp fittings are going to be a lot cheaper and won't restrict that much unless you use the pex elbows. (and a lot of them)

[mlappin]

Since you have PEXa, you can use the expansion type fittings. They do require special tools but the Rehau Everloc fittings are much better than anything else. The Wirsbo style expansion can also be used but they aren't as good as Everloc but do have the larger inside diameter. I saw Menards is now selling the Wirsbo style and the tools are cheaper than for everloc.

Regular crimp fittings are going to be a lot cheaper and won't restrict that much unless you use the pex elbows. (and a lot of them)

 

[schoppy]

Thanks everyone. I talked with a Rehau rep today and he recommended their brand of course but I will have to check them all out. Need to do a few checks that slimjim also recommended and have my water tested again after loosing a lot of my treated water. One other note, I contacted Sharkbite also and one rep told me that all their fittings have the shark imprint on them if they are sharkbite brand fittings.