Boiler plumbing primary/secondary vs single loop. pro's and cons

Frank F wrote: ↑

Sun. Nov. 11, 2018 6:55 am

I'm not sure off hand but I thought it was 6.6 or 6. Something gal. I'll double check.

The total tank volume is 7.6 but that's not important. The acceptance volume is only 2.5 gallons. That ain't nearly enough. Even 2 of them is probably not enough. I would not buy another one since you are not installing this in a multi-story building.

You should figure out how much total water is in your system. I'm sure Amtrol has a guide online somewhere that will tell you how much expansion (acceptance) volume you need.

-Don

StokerDon wrote: ↑

Sun. Nov. 11, 2018 9:00 am

The total tank volume is 7.6 but that's not important. The acceptance volume is only 2.5 gallons. That ain't nearly enough. Even 2 of them is probably not enough. I would not buy another one since you are not installing this in a multi-story building.

You should figure out how much total water is in your system. I'm sure Amtrol has a guide online somewhere that will tell you how much expansion (acceptance) volume you need.

-Don

Ok thank you. I will figure it out.

Well I screwed up. I have thermopex ran under the ground it's 1-1/4 PEX. So I assumed it's outside diameter was 1-1/4. I built the manifold out of 1-1/4 copper. Then i ran 1-1/4 PEX (that I bought online because dealers here do not carry that size) indoors from the manifold to the thermopex that comes through basement wall .
Well turns out the thermopex is actually 1-1/2 outside and just shy of 1-1/4 inside. So the fittings I ordered don't fit.
The delema...i know the right way is to rip it all out and replace it with 1-1/2 pex to increase volume. I will have to remove the 100' of clamped PEX. BUT I JUST GOT DONE RUNNING IT AND ITS NOT VERY FLEXIBLE. Why didn't I measure first.

Hang on Frank, don't go crazy yet. I thought the Thermopex that you ran underground was 1.25"? If so, the rest doesn't need to be any bigger than 1.25"

I don't understand why you are concerned about the outside diameter. Pipe is all inside diameter, tubing is outside diameter.

It sounds like you have 1.25" Thermopex, 1.25" PEX and 1.25" copper. That sounds right. If you have the wrong size fittings return them and get the right size fittings.

-Don

StokerDon wrote: ↑

Sun. Nov. 11, 2018 9:44 pm

Hang on Frank, don't go crazy yet. I thought the Thermopex that you ran underground was 1.25"? If so, the rest doesn't need to be any bigger than 1.25"

I don't understand why you are concerned about the outside diameter. Pipe is all inside diameter, tubing is outside diameter.

It sounds like you have 1.25" Thermopex, 1.25" PEX and 1.25" copper. That sounds right. If you have the wrong size fittings return them and get the right size fittings.

-Don

I measured the thermopex. It's 1-1/4 inside diameter.

The 1-1/4 pex I ordered for in the house is 1" inside diameter.

It sounds as if ThermoPex might be PEX-AL-PEX, which is a special kind of PEX. It has an aluminum barrier embedded within.

PEX-AL-PEX is the only PEX which gives you effectively copper pipe 'like' ID's, but at the expense of noticeably wider OD's. There should be transition fittings available which will take you from PEX-AL-PEX to normal PEX or to copper.

PEX-AL-PEX is very good stuff. Its extra ID will permit your circulator to move far more BTUH than does standard PEX. Once you solve the transition issue you will be very happy to have the increased ID.

StokerDon wrote: ↑

Sun. Nov. 11, 2018 9:00 am

The total tank volume is 7.6 but that's not important. The acceptance volume is only 2.5 gallons. That ain't nearly enough. Even 2 of them is probably not enough. I would not buy another one since you are not installing this in a multi-story building.

You should figure out how much total water is in your system. I'm sure Amtrol has a guide online somewhere that will tell you how much expansion (acceptance) volume you need.

-Don

Hey Don as always thank you for your help. I can't lie the plumbing store helped me determine the tank size and I trusted that they knew what they were doing(not a big box store).

So I calculated my system to hold 65.58 gal of water. What size would you go with? I looked at the charts but I don't see anything related to acceptance value. It looked to me like a st-12 would be the right size.

Please let me know what you think.

Thx Frank.

lsayre wrote: ↑

Mon. Nov. 12, 2018 5:54 am

It sounds as if ThermoPex might be PEX-AL-PEX, which is a special kind of PEX. It has an aluminum barrier embedded within.

PEX-AL-PEX is the only PEX which gives you effectively copper pipe 'like' ID's, but at the expense of noticeably wider OD's. There should be transition fittings available which will take you from PEX-AL-PEX to normal PEX or to copper.

PEX-AL-PEX is very good stuff. Its extra ID will permit your circulator to move far more BTUH than does standard PEX. Once you solve the transition issue you will be very happy to have the increased ID.

I dont see any aluminum. When I look on the PEX sizing chart it measures at the 1-1/2 PEX size. OD=1-1/2, ID is roughly 1-3/16.

Frank F wrote: ↑

Mon. Nov. 12, 2018 7:22 am

I dont see any aluminum. When I look on the PEX sizing chart it measures at the 1-1/2 PEX size. OD=1-1/2, ID is roughly 1-3/16.

I think I figured it out. Thermopex is listed as pipe, where as the PEX I ordered from badger heating is listed as tubing. So when I ordered the two I just assumed 1-1/4 would be the same. But they are not. Badger tubing online has a pic with sizes. The 1-1/2 = same size as my 1-1/4 thermopex.

Use this Amtrol worksheet to size your Extrol.

Hello again,
I'm ready to purchase a water to air heat exchanger for my plenum. Are there any brands or manufacturers that you would point me too.

I found a few on Google but want to make sure I'm purchasing a quality product.

As always thank you for your guidance.

Frank

Brazetek are American made, I have one.

Most others are made in Chiner

Mine is Magic Aire but you would need to go through a contractor, they don't sell to homeowners. Not sure if they are american made but come out of TX

Frank F wrote: ↑

Mon. Dec. 17, 2018 10:01 am

Hello again,
I'm ready to purchase a water to air heat exchanger for my plenum. Are there any brands or manufacturers that you would point me too.

I found a few on Google but want to make sure I'm purchasing a quality product.

As always thank you for your guidance.

Frank

Badgerinsulatedpipe.com

I’ve purchased two water to air and a water to water from these folks, along with all my pex and circulator.

Update. I finally got my welder fixed so I was able to build a box to install the coil.