Flat Plate Hx Survey - Brand and Price Information Requested

[DenaliChuck]

Could you post the size, brand, vendor and price you paid for your flat plate hx?

Any other advice?

Thanks,

DC

 

[pybyr]

I have a GEA/ FlatPlate 5x12 inch x 70 plate, and got it from the ebay vendor (I think it was KJmotorsports or something like that) that deerefanatic had mentioned here in the boiler room. I think I paid about $699 for it, new in box, which was way less than what any other source I found was asking for a similar size.

 

[jebatty]

I did all my shopping off of e-bay. Brazed plate. I recommend at least 1" ports, 5" x 12", and 30 or more plates. Mine is a 30 plate with a Tarm 40. Some others are using 70 plate. More than 30 probably is better, and ideal would be a calculation based on flow, btu's and delta T that strips all the heat the boiler can deliver. Mine does at lower temps, but from about 120F input and up, boiler does go through idle cycling. I regard this as not perfect but reasonable and I am very satisfied.

 

[pybyr]

More than 30 probably is better, and ideal would be a calculation based on flow, btu's and delta T that strips all the heat the boiler can deliver.

Before picking and buying, I actually spoke with one of the application engineers at GEA/FlatPlate, who was very patient and helpful. However, the huge swings of variables with storage in this application (you get steadily varying delta Ts and inlet and outlet temps not only when charging the storage, but also when pulling the heat back out) made it really hard for them to model using normal techniques and software that they use in other applications. The application engineer finally had me pick a set of parameters- boiler output and worst case house heat load and illustrative scenarios (hot boiler, cold storage, hot boiler, storage near full charge, hot storage with peak house heat load, marginial/ nearly-depleted heat storage) and then plugged those into the models one at a time.

In my situation I really want to be able to be sure that I can push the storage as hot as possible on the charge cycle, and keep extracting useful BTUs to as low a temp as possible on the "draw" cycle, as this will maximize the effective useful thermal capacity of the storage.

anyway, with that modelling assisted by the fellow from GEA (and I should say that they were great and patient and kept saying "that's what we're here for") -- in my situation, 30 plate definitely looked undersized, but not awful. 50 to 60 plate looked like it would probably be pretty good. but then I found that, at least from the source I used, the incremental cost of 70 over 50 wasn't that high, and I decided that I'd rather spend the extra bit and know that I'd gotten the most efficient reasonable heat transfer that I can

hope that's helpful

 

[jebatty]

in my situation, 30 plate definitely looked undersized, but not awful.

I previously used (approx) 4 x 8 x 24 plate with 3/4 inlet/outlet and that was awful. The 5 x 12 x 30 plate is very usable, which I got for about $200, but I agree that larger would be better. I'm learning by trial and error. The advice to go to 50 to 70 plates likely is very good advice in general.

 

[DenaliChuck]

Thanks guys!

I too called GEA/Flat Plate and their engineer helped me size a plate using these parameters. My Tarm will be directly connected to storage; I need the hx between the Tarm/Storage and the house.

With 30% glycol (in the house) and water in the Tarm/Storage:

15* approach (125* input, 110* output) would require a 5x12x40 plate
10* approach (120* input, 110* output) would require a 5x12x90 plate

Interestingly, using water on both systems would only require a 5x12x24 (with a 15* approach)...of course, using water on both would mean I wouldn't need a hx anyway. Something I'll consider.



Any other brand, sources and price advice out there?

DC

 

[WoodNotOil]

I got the 30 plate 3/4" from here http://www.radiantheatproducts.com/store/cart.php?m=product_list&c=14 but wish I had oversized it a bit more. I like the sound of the 70 plate ones pybyr and deerfanatic got.

 

[russlaw]

I am looking for a heat exchanger for domestic hot water. Any ideas on the size required for that? I built a box around my 500 gal tank, insultated with double sheets of 2 inch styrofaom and filled between the tank and insulation with sand. I also installed two loops of 3/4 inch copper and laid them on top of the tand (approx 35 ft) and run a loop system between that and my electric heater (electricity off). It heats the DHW just fine for two of us but takes time to re-coup if you use a lot of hot water. Had I used double the amount (70 ft) I don't think I would have had any problems. The sand has not dried out yet (1 week with 140 to 190 degree water) and it might work better once is is dry. I was hoping that would be a good conductor of heat and retain the heat in the tank longer. The jury is still out on that one. I just started 2 weeks of burning my EKO and it is definitely a learning process. I am searching for tips on getting the boiler to gasify better and also if I should let it burn out and start new fires or keep some wood in it when idiling. Cresote problems are telling me that I should burn hot and let it go out but I'm open to any suggestions.

Thanks
Russ

 

[mwk1000]

I found the GEA web site http://www.flatplate.com/resources_SOFT.htm has an online calculator. It was VERY useful in sizing the HX. I selected Hydroponic/Liquid-Liquid and started doing What if ??? cases for my system. It recommended a 12x70 at 8 GPM and a 12x40 at 10 GPM for my particulars. A wonderful sanity check. It also showed the entering/exiting temps for all sides and the flow rates needed on both sides.

FYI Cozy Heat is selling 5x12 - 70 plate for $587 right off their site http://www.cozyheat.net/platespecs.htm

 

[jebatty]

Be sure to check e-bay on 5 x 12 x70 - $360 with free shipping currently is being advertised.

 

[rowerwet]

I also went the Ebay route, freeheat4U had a nice rough chart on its listing. my oil furnace is a 50,000 btu model, by the chart up to 150 btu only needs a 20 plate so that is what I got. it is a 5"x12" with 1" fittings for $179 free shipping. so far so good.