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[wormmister]

Is a 20 plate heat exchanger large enough for a family of four adults?
Thanks.
Wormmister

[mlappin]

You talking a 3x8” or a 5x12”?

I’m running a 20 plate 5x12” fed by a mono flo t, I can turn all the hot taps on in the house and notice no drop in water temp.

[aarmga]

From what I've read plus all the information everyone on here has told me I think I would lean more towards a 30 plate just for the resistance of the 20 plate.  I have a 3x8 30 plate that will be installed this summer.

[schoppy]

mlappin is right on the money. I have a 10 plate 5x12 with 1" ports fed by mono flow tees (thanks Slim) with a family of 4 including a teenage girl and I only have issues if multiple taps are turned on at the same time. I will be going to a 20 plate with 1" ports when and if my 10 plate ever takes a crap.

[E Yoder]

I would say 5X12 = 20 plate. 3X8 = 30 plate. Minimum. Would be more critical to have a 5X12 if your system is high flow ( above maybe 6 gpm).
I've got a 3X8 30 plate with 7 people in the house. Never run out if hot water. I've showered 17 people when we're all here at thanksgiving.

[wormmister]

Thanks everyone.
I have about a 60 foot run(1 inch logstor)into a 4 port manifold, short run to the furnace(1 inch copper) , using a grundfos 15/58.
Hope to add a hx for dhw and something for my pool/hot tub.
Do I need a bigger pump?
Thanks for all the help, I've learned lots just from reading on this forum.

[RSI]

If you are putting in series with everything then I would use a 30 plate minimum. If using smaller than a 5x12 then probably 50 plate.
If using monoflow tee setup then you can use smaller.

If you have spare ports on the manifold and want to hook to those. you could use 20 plate but you will probably have to increase pump size to lot lose too much through the current loops off the manifold.

[E Yoder]

This is a 3x8 " 30 plate on the 110' 1" main loop. Secondary loop 3/4 Pex runs about 40' to a 5 ton heat pump with coil. Heated great. Ran about 20-25F deltaT when heat was running. Domestic gets first priority. . 140F domestic water coming out of the exchanger.
 NRF-22's running both loops.

I'm not disagreeing with RSI who is way smarter and experienced than i,  just showing what we do.

[RSI]

I am sure that heat exchanger would work fine but with the piping and pump mentioned it would likely restrict the flow quite a bit from the current setup if put in series. Using a larger (more plates) will add minimal head pressure.

[E Yoder]

You're right. I think what I'm doing adds restriction, I just try to minimize 90's, etc to keep other restrictions down. And stacking zones in order of priority and supply temp.  Seems to have enough flow judging by the Dt. But if there are a lot of high flow zones it would never work.

It's funny how many times I've seen large flat plates to minimize restriction, then a whole whack of 90's and valves on a 2 or 300' run. We saw like 20-some 90's on one basic loop a while back. Looked nice though. 

[mlappin]

Be nice if somebody would make some long radius pex elbows like you can get in copper.

[RSI]

Do you mean like this? http://www.siouxchief.com/products/supply/powerpex-systems/astm-f1807/directionals/elbows/copper

[mlappin]

cool

[aarmga]

I just ordered some of those.  Thanks RSI