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[donahuej]

Hi all -

Quick question; how much heat loss do you see across a 30 plate heat exchanger?  I have a 30 plate stainless with 1" supply and returns, 1" copper for my boiler and well water supply loops and I see 25 -30 degree drop when filling the big tub in the house. My boiler uper limit is 180 degrees lower is 170ish. I have digital temp gauge with leads zip tied and metal taped to my copper lines right after the thermopex enters the crawl so my readings are right on the money. Normal or what?  I have a constant supply of really hot water, not complaining, just want to see what others are experiencing..

Thnaks,

Jamie

[gmviso]

Well, I have  5 x 12 - 20 plate exchanger with 1" supply and returns and see a drop of about 22 degrees across it when running my tub spout full open. But, note what my brazed plate exchanger dealer states that Any brazed plate heat exchanger can have higher or lower performance data based on temperatures, flow rates, and other variables.

That being said yours is probably about right.

[RSI]

It depends on how big your pump is and how much pipe you have. If you want less temperature drop you would need a larger pump.

[donahuej]

B&G PL36 about 400 feet of 1" copper suppling DHW and two water to air exchangers.

[Scott7m]

B&G PL36 about 400 feet of 1" copper suppling DHW and two water to air exchangers.

What's the deal on 400 feet of copper?  Is it underground?

[donahuej]

Sorry 140 feet (round trip) of therompex in that number.  The coper is in the crawl...

[RSI]

So you have 400' of copper and 140' of pex in the loop?
For every elbow in the copper you need to add 5.2 feet to the length when figuring restriction.

With the length of pipe you have and a big heat load like that you should be fine with that temperature drop.

[donahuej]

240' copper - 140' pex total 400' did not add the 90's...thanks for the help.  No problems just was wondering what y'all were seeing.

Thanks again,

Jamie

[fireboss]

scott, what side of the ex should the bigger pump be on ? I have taco 007 on both sides of my ex, i have a 011 sitting in a box on the floor not shore witch side to put it on to get the most out  of the ex.

[Scott7m]

scott, what side of the ex should the bigger pump be on ? I have taco 007 on both sides of my ex, i have a 011 sitting in a box on the floor not shore witch side to put it on to get the most out  of the ex.

Not sure which side would be best.  RSI knows a lot more about pumps than I do

[RSI]

What is each side pumping through?

[fireboss]

one side comes from the wood furnace 14' away, pump is at wb. the other one just goes to the oil burner and back to ex 2' round trip the ex is at the oil burner both pumps run continously. I have a third pump that pushes it up stairs!

[RSI]

It would probably be best to put the 0011 on the outdoor boiler side of the plate. It you only have 2' of pipe on the indoor side the 007 should be moving a lot of water. (assuming it is at least 1" and not all elbows)

How much temperature drop are you getting between the supply and return lines on the outdoor loop?

[fireboss]

not sure how accurate  but the wb set @ 195  and it returns @180 I only have a gauge on the return side of wb!

[RSI]

Can you move the gauge easily? If so put it on the supply side and see how it compares to the boiler gauge.