One boiler for all...

MINO · Post by **MINO** » Sun. Oct. 14, 2018 8:05 pm

To make a quick post other than trying to write a book to explain what I want to do...I have 2 boilers a Efm 520 (house) 3600sq ft and keystoker k6 (garage)28x40 radiant floor.... house is 6 zones all cast iron baseboard approx 450 linear feet total and garage is 6 loops approx 250ft a loop... I have the boilers linked underground with closed cell 1 inch pex pipe just as a backup if a boiler goes down but mostly they are ran independent of each other for general heating... 520 heats house without a problem(well insulated) k6 does garage basically on idle.... I did at one time run the k6 to heat it all... unhooked power off of the motor of the 520 and it ran all thru the k6 it kept up until the windchill was -20 for cpl days and the primary zone of house had a hard time satisfying ..... I would like to unload the 520 and k6 to put a bigger unit in garage .... and because heights of the boiler it made pressure increase in basement 25psi and 8-10 garage... I would like to run just a heat exchanger that I have from my swimming pool it’s roughly 400,000 btu shell n tube in the house and a plate exchanger for indirect water tank for domestic hot in the house...but not sure how to hook it up with expansion tanks and auto fill n blow off and gauge in the house??? Make a manifold with all of them on it?? And would I get enough heat transfer with just one inch pex? It did before no problem but the unit was undersized for what I was trying to achieve ... basically looking to keep mess in garage and not tend to two boilers during the winter months... I’m open to another keystoker... k10?ahs260? Would like some input more on the tying into the house plumbing with just a heat exchanger where the boiler in house use to be.... thx

Post by **Rob R.** » Sun. Oct. 14, 2018 8:12 pm

Why not just heat both buildings with the 520?

MINO · Post by **MINO** » Sun. Oct. 14, 2018 8:45 pm

I could move it out to the garage... but looking maybe a bit bigger unit... I have a great idea of how to hook it up with an exchanger in house but would love to hear input on how to pipe it and I get the heat response won’t be as quick as the boiler dumping into the zone it will be a gradual increase circulating thru the exchanger... just looking for comments on people who do it this way if at all...

hotblast1357 · Post by **hotblast1357** » Sun. Oct. 14, 2018 9:11 pm

What’s the reason for the heat exchanger in the house? Why not have it all one system?

MINO · Post by **MINO** » Sun. Oct. 14, 2018 9:19 pm

Possibly to keep them separate??? I could pipe it into my existing manifold and have it run that way but I still will need a heat exchanger to keep the domestic holding tank up to temp.... I was just concerned about pressures being different because it will be 110 ft one way before the 6 zones would get a shot of heat from the boiler in garage.... I have a taco 011 to push between the boilers if need be

hotblast1357 · Post by **hotblast1357** » Sun. Oct. 14, 2018 9:25 pm

MINO wrote: ↑
Sun. Oct. 14, 2018 9:19 pm
Possibly to keep them separate??? I could pipe it into my existing manifold and have it run that way but I still will need a heat exchanger to keep the domestic holding tank up to temp.... I was just concerned about pressures being different because it will be 110 ft one way before the 6 zones would get a shot of heat from the boiler in garage.... I have a taco 011 to push between the boilers if need be

You would most likely need to have constant circulation from garage to house.

My 260 is 80’ from my house, and I only have a grundfos 15-58 set on speed 2.

As I understand, pressure is more for height requirements.. not distances.

windyhill4.2 · Post by **windyhill4.2** » Sun. Oct. 14, 2018 9:36 pm

1 of my Taco 007 is pushing thru 600' of 1" pex. My 520 heats 2 houses & dhw for both + my 30x40 Repair shop.

MINO · Post by **MINO** » Sun. Oct. 14, 2018 9:36 pm

Yes... before when I heated with one unit I had it 24/7 circulating with the 011... but with them linked the 520 is approx 8 feet lower than the k6 in elevation and the k6 has low pressure 7-10psi while the 520 was pegging at 27 ish...

MINO · Post by **MINO** » Sun. Oct. 14, 2018 9:38 pm

Windy hill is it all closed loop or do you run heat exchangers?

windyhill4.2 · Post by **windyhill4.2** » Sun. Oct. 14, 2018 9:47 pm

MINO wrote: ↑
Sun. Oct. 14, 2018 9:38 pm
Windy hill is it all closed loop or do you run heat exchangers?

Boiler loops are closed.
I use water to water plate heat exchangers for the DHW.

Post by **Lightning** » Sun. Oct. 14, 2018 11:35 pm

MINO wrote: ↑
Sun. Oct. 14, 2018 9:36 pm
Yes... before when I heated with one unit I had it 24/7 circulating with the 011... but with them linked the 520 is approx 8 feet lower than the k6 in elevation and the k6 has low pressure 7-10psi while the 520 was pegging at 27 ish...

Change in elevation would result in difference of feet × .433 psi. So if one boiler is higher by 10 feet, they should see a static difference of 4.3 psi. The higher pressure at the lower boiler of course.

lzaharis · Post by **lzaharis** » Mon. Oct. 15, 2018 12:21 am

Purchase a copy of "Classic Hydronics" and a copy of "Pumping Away" from www.dansbooks.com to help you solve your plumbing issues and correctly install the new boiler or reinstall one of the boilers you have already.

lsayre · Post by **lsayre** » Mon. Oct. 15, 2018 5:28 am

hotblast1357 wrote: ↑
Sun. Oct. 14, 2018 9:25 pm
As I understand, pressure is more for height requirements.. not distances.

In a closed loop system distance (length), pipe inner diameter, and pipe material make-up (consider it a smoothness or internal friction factor), determine pressure drop, and height is completely irrelevant. Fittings like elbows increase the systems "effective" distance (length). For closed loop systems there is only "friction head". There is zero "head" related to height. This is why closed loop systems use circulators, and not pumps. If you are "pumping from point A to point B, then height matters (in addition to all of the above), but if you are circulating from point A to point A, it does not. Any effort and energy required to fight gravity on the way up (exerted kinetic energy) is completely negated by the fall within the very same gravity field on the way down (liberated potential energy) and only friction remains to be considered in conjunction with "effective" length.

If you do not know the sum total of the effective lengths of your loops fittings, a typical first reasonable guess is 'generally' that effective loop distance (length) is 1.5X actual loop distance.

hotblast1357 · Post by **hotblast1357** » Mon. Oct. 15, 2018 5:44 am

Your 1” pex line in the ground MIGHT be your limiting factor anyways, so put the 520 in the garage, run everything off it in one closed loop, put a water to water in the house for your dhw, and see what it does.

If anything I would put the ka6 next to your EFM, and for those couple of brutal cold weeks if the efm can’t do it, you light up the ka6 to assist.

Why buy another boiler when you have two already..

Windy hill is heating a lot with a 520, going a long ways also..

Post by **StokerDon** » Mon. Oct. 15, 2018 6:41 pm

In my opinion, and this is only an opinion,

If you are truly going to one boiler. And you already have a 520 in the basement of the house, where the biggest heat load is. The answer is simple, leave the 520 in the basement and heat the garage through the 1" PEX.

If you try to put the 520 in the garage to heat the house, the 1" PEX will be the limiting factor as stated above. Why would you want to put a limiting factor on the heat for your home?

If you have a mess in the basement, it's probably because you are moving the coal. Put the auger from the 520 into the bin so coal doesn't need to be moved into a hopper or barrel. Then clean ups will only be needed occasionally.

-Don