FredSolar

FredSolar

I am upgrading my ancient homemade solar hot water system, and am wondering if a 119 SSU HTP tank will be suitable in a glycol system.  I note it has great specs, with a relatively short in-tank finned heat exchanger, but I also note I seems to be designed for a boiler system heating the water at what appears to be a higher gpm rate than my system will be running.   Is it suitable for a solar system running glycol, with 4x8 panels, at around 5 gpm?



Thanks for any information,

Fred 

hot_rod

the more hx surface

the better when transfering solar energy. Usually the manufacturer will list the square feet of transfer surface for you to compare.



That is a fine tank and I believe it has a finned coil with plenty of surface area. if you have a large array or want additional performance you could buy a dual coil tank. Then you could either stage the coils, heating the top of the tank first for quicker recovery. Or series the coils so you double the HX surface. Watch the pressure drop when you series the coils, some brands use a small diameter coil, and putting them in series could require more pump power.



hr

Charlie from wmass

Could you reverse return

for the coil piping Hot Rod? I do no solar but I was thinking even for indirects off of a boiler I could run lower temps if I used a dual coil and reverse returned the piping.

Karl_Northwind

reverse return

I think you'll find many of the indirect dual coil tanks have different sized top and bottom coils, and you'll only get even flow reverse return if the flow paths are the same length/resistance. 



I know the upper coils in the HTP tanks are smaller than the bottom coils.



to the original post, SSU tanks are plenty nice, and have an efficient coil.  the Cupronickle coils have better transmission than the smooth steel coils in the SSC tanks.  unfortunately comparing the same SF of smooth coil vs SF of finned cupronickle aren't really apples and apples.



we have connected coils in series with no problems, as long as the flow rates aren't high. 

they have all been the smooth coils, so flow resistance is low, and they're 1'' coils, with 3-5gpm thru them.



karl

CC.Rob

fine

FWIW, I really like my SSU-119. It's in a glycol system. Works great.

FredSolar

thanks

Thanks for the reply and the confirmation that it's the tank for me.   Fred

FredSolar

thanks to hot rod

A belated thanks for your reply too.   I have gone with this tank, and am looking forward to installing it.   Fred

Charlie from wmass

Karl I was told the reason for

reverse return is to try and equalize unequal paths. on heat emitters.