Heat Exchanger (HX) question

[urhstry]

Can someone tell me the difference between a 30plate brazed HX costing $1000+ and one somewhere else (Ebay -freeheat4U) for $200??

I can't see the difference on the spec sheets. :monkey:

 

[November Wolf]

I don't know what the difference is either but I just bought one on ebay for $249 for a 40 plate. It is brand new and looks to be good quality. I have'nt installed it yet but I will soon. I am waiting for my Central Boiler to arrive. I bought my heat exchanger from that freeheat4u guy.

 

[urhstry]

Maybe nobody else knows...:monkey:

 

[fletcher0780]

Can someone tell me the difference between a 30plate brazed HX costing $1000+ and one somewhere else (Ebay -freeheat4U) for $200??

I can't see the difference on the spec sheets. :monkey:

some are rated for gasses (ammonia and such) for cooling environments, and some are just rated for water. Just make sure it's a decent brand (triangle tube, flatplate, etc) and meets your flow requirements. I use a 30 plate I got from here:
http://www.ccallis.com/flatplate_heat_exchangers.htm

 

[windthrown]

I have had good luck with Flatplate HX's. They have a fast recovery time and they seem to last without sluffing off or clogging up. I think a large one was about $250 whenI installed it. The hot water heater size one was about $100. But that was 4 years ago...

I would think that cheaper ones would delaminate, or the plating metal would flake off inside. You would have to look at the build quality and compare them over time. Hard to say from just looking on Ebay. Ebay is filled with a lot of cheap crap and knockoffs.

 

[Scootermsp]

Marine Grade

Can someone tell me the difference between a 30plate brazed HX costing $1000+ and one somewhere else (Ebay -freeheat4U) for $200??

I can't see the difference on the spec sheets. :monkey:

The 30 plate $1000 model is marine grade Stainless that you would need to heat a swimming pool or spa(due to chemicals, chlorine, etc.) I have a standard 30 plate that I heat 4800 Sq Ft with and it works well. Got mine from my CB dealer for $300 ish....hope that helps......also do not forget to install a "Y" strainer at each inlet.

 

[urhstry]

Fletcher, thanks for the link. I also thought about the delaminating, Windthrown. The ones I looked at on Ebay are lifetime warranty. I know that may not mean a lot but if you have it use it, it's there.

Scooter, did you add TWO Y-strainers or 4? I saw a picture on here of a HX with all four ports with a Y. How much hot water do you use with that 30pl? I am going to heat an 1800sq ft with hot water in my garage in a small (trailer) hot water heater. Thanks!

 

[windthrown]

Should only need 2 strainers on the inlets. Though I only used one on the boiler loop inlet. The house floor loop already had a strainer in it.

 

[Scootermsp]

Hx

Fletcher, thanks for the link. I also thought about the delaminating, Windthrown. The ones I looked at on Ebay are lifetime warranty. I know that may not mean a lot but if you have it use it, it's there.

Scooter, did you add TWO Y-strainers or 4? I saw a picture on here of a HX with all four ports with a Y. How much hot water do you use with that 30pl? I am going to heat an 1800sq ft with hot water in my garage in a small (trailer) hot water heater. Thanks!

I only one "Y" on the OWB loop inlet. As far as domestic hot water goes---3 women in the house (need I say more?). My DHW is a zone off the boiler to an 80 Gallon super store (Amtrol). The 30 plate pulls anywhere from 10 - 30 degrees off the OWB water as it passes. If you find the thread "Light it up" I have photos posted of my HX set-up.opcorn:
http://www.arboristsite.com/showthread.php?t=76966

 

[John D]

I am plumbing my HX now,I am doing the same as your setup scooter.last night i shut down the boiler,and added Ts and shut offs on the drain,and blowoff valves.Today i am going to hook it all up to the HX. I have a 50 plate exchanger.My plumber says i should use 1" from the hx to the boiler.The inlet/outlet is 3/4" .
Scooter,do you have any problems with the 3/4" setup not being able to keep the boiler hot enough when more than one zone is on.The total feet of 3/4" run is about 10 ft,so it isnt a long loop. I have 3 zone,a 40 gal superstore,and 2 heat zones,one 1500 sq ft,the other 1750 sq ft.At times they are all on at once.I just dont want the boiler to need to come on when al the zones are pulling.

 

[Scootermsp]

No problems

My set-up keeps up easily. CB dealer said anything over 30 plate was waste of $$$. All 4 zones and DHW calling for heat will not overwhelm the HX as long as there is wood in the "DOG". DHW and 4800 sq ft is what I heat.

 

[John D]

Thank you. We bought a package deal of the 50 plates,got them cheaper than most 30's,and some of the guys using them are heating 7500 sq ft,kinda needed the 50 plates for them,so i got a 50,I may even be able to get away with running the 3 speed circulator on low.

 

[windthrown]

I am plumbing my HX now,I am doing the same as your setup scooter.last night i shut down the boiler,and added Ts and shut offs on the drain,and blowoff valves.Today i am going to hook it all up to the HX. I have a 50 plate exchanger.My plumber says i should use 1" from the hx to the boiler.The inlet/outlet is 3/4" .
Scooter,do you have any problems with the 3/4" setup not being able to keep the boiler hot enough when more than one zone is on.The total feet of 3/4" run is about 10 ft,so it isnt a long loop. I have 3 zone,a 40 gal superstore,and 2 heat zones,one 1500 sq ft,the other 1750 sq ft.At times they are all on at once.I just dont want the boiler to need to come on when al the zones are pulling.

3/4 copper is about the same internal diameter as 1 inch PEX. Different standards, but all my copper was 3/4 inch (on the boiler, top elevation bleeder manafold, and at the Hx) and all the PEX was 1 inch.

In our system I ran the boiler to the DHW Hx first, and that ran all the time. The Hx on the DHW was at the bottom of a 3/4 inch copper loop that I plumbed form the drain to a tee at the inlet at the top. Worked good, solely on convection. Hot water rises, keeps the hot water pleanty hot, with a good recovery time. We never ran out of hot water. The boiler loop then went into the hydronic floor Hx and then back to the boiler.

The other side of the Hx was plumbed into an existing electric boiler pressurized (by house water pressure) hydronic floor heating loop, which came on by demand of the thermostat. The outlet of the Hx in that loop was plumbed into a mixing valve to mix floor return water with the Hx water. We kept that at 100 degrees, as the house was all hardwood floors and tile. BTW, we also had a mixing valve at the outlet of the hot water heater; keeps scalding water from getting to the sinks and tub.