Head calculations for HE?

[MarkW]

I have a 16x18 and 12x12 exchangers and wonder if anyone might suggest where I can find the head figures for these?
Thanks!

 

[Karl_northwind]

I have a 16x18 and 12x12 exchangers and wonder if anyone might suggest where I can find the head figures for these?
Thanks!

Are these for water to air? I've never seen anything those sizes in liquid to liquid.
the sizes of air HX's I use (from 18x18 to 24x24) all have a pressure drop of about 1'-2' head (1/2 to 1PSI) at the appropriate flow rates for the HX BTU output.
shot in the dark but hope it helps.
karl

 

[Bob Rohr]

Are these for water to air? I've never seen anything those sizes in liquid to liquid.
the sizes of air HX's I use (from 18x18 to 24x24) all have a pressure drop of about 1'-2' head (1/2 to 1PSI) at the appropriate flow rates for the HX BTU output.
shot in the dark but hope it helps.
karl

That data should be available from the manufacturer. The head, or pressure drop depends on the flow rate you intend to run through it.

 

[MarkW]

Thanks Karl. That gives me something to go on.

Nothing available Bob. I suppose I could calculate the tube lengths and count all the elbows and come up with something that way but I'm just trying to get close.
I punched in some guess into a calculator app and came up with 9' for one of the HEs. I don't think that was quite right so I'll prefer to go with someone elses guess.

Edit: Yes, it is liquid to air. Liquid to liquid would sure xfer the btu's at 16x18, huh!

 

[Bob Rohr]

Thanks Karl. That gives me something to go on.

Nothing available Bob. I suppose I could calculate the tube lengths and count all the elbows and come up with something that way but I'm just trying to get close.
I punched in some guess into a calculator app and came up with 9' for one of the HEs. I don't think that was quite right so I'll prefer to go with someone elses guess.

Edit: Yes, it is liquid to air. Liquid to liquid would sure xfer the btu's at 16x18, huh!

fill it with water, dump it out and see how much fluid it holds. Measure the tube size, go online to CDA or one of the engineerstoolbox sites to see how many feet of tube that equates to. Count the u bends and calculate the 'footage' of tube that equals.

that's how we determine how long a buried pex loop is, measure the water contend and use the manufacturers data sheet for fluid capacity per foot, generally per 100 feet.

 

[MarkW]

Clever idea.

 

[Karl_northwind]

I have spec sheet for a 20x20, and it lists .6 Ft head at 5 gpm, and 1.1 Ft head at 7 gpm. I can request other ones but that's the smallest I have on hand.
karl

 

[MarkW]

Thanks Karl. That's more like it.