Finding a Dual Coil Indirect

prm_8

I'm looking for a dual coil indirect so I can use my boiler and a solar panel as heat sources.

According to my local distributor, the dual coil superstor's are actually single coils with a double wall. Are they wrong? They suggested a traditional indirect and a plate heat exchanger and circ for the solar end.

What are some other sources of dual coil indirects?

Is there a real risk failure contaminating the potable water with glycol?

Firedragon_4

Go with two heat exchangers, the

risk of contamination is VERY high, FACT!

Unknown

two different animals

Noel

Constantin

I could be wrong...

but I believe the folks at Viessmann offer true dual coil tanks (i.e. 4 nipples, two sets of coiled tubes). The lower coil is meant for solar gain, the upper for the heating of water. Take a look at this Vitocell Manual, it shows the dual coils (Vitocell B-300) in a cutaway view on page 6.

Unknown

These tanks had two isolated coils.

I just needed a LOT of hot water for a four story girls' dorm.

A vapor system is driving this thing, using the water from the steam boiler.

Noel

Constantin

Hi Noel!

My post was in reply to the original inquiry via PRM, not your picture... sorry!

Anyway, IIRC, prm was looking for a safe way to intgrate solar and IDWH heating. The vitocell B-300 seems suited for that purpose, though I wonder at what price point they're sold and whether having a single wall between water and glycol is good enough. A call to Viessmann in RI may clear up that question also.

Cheers!

Uni R

Dual coils

Vie$$mann of course, plus many others...


http://www.aosmithinternational.com/English_Products_Indirect.html#ITSinfo


http://www.heatexchangersonline.com/indirectwaterheater.htm


http://www.aeroso.com/phys_spec.html model 75D


For Ireland, you have http://www.coppercraft.ie/ at bottom

Robert O'Connor_3

TFI -everhot

says they'll make a dual coil indirect.

www.tfi-everhot.com

GEO_3

Superstor

Superstor was making a double coil commercial tank. It had 2 separate coils. I think thats whats in the picture.

Dan Peel

another one - CDN

try www.metalpres.ca great with solar - upper and lower indirect coils. Dan

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Ted_5

Viessmann Tank

They due have two coils. Made for a Solar system. All 316Ti stainless steel, large 1 1/4" coil size and alot of surface area. All smoth coil, so there is less chance of build up on the coil. The solar or boiler water only needs to be 15 deg. over what you want your tank temp to be. For example, 120 DHW you only need 135 deg. water to recover.
On an overcast day a good colector will give you that.
Check into it!

Ted

hr

Crown can supply them

as well as Super Stor DP (dual purpose) series, 40, 60, 80, and 119 gallon are shown in their catalog. Super Stor also has an optional electricial ellement tap, an electrical element back up.

Depending on local codes solar with propylene glycol may not require double walled HX's.

hot rod

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Brad_9

Dual coil

The HTP tank is not very suitable for solar and indirect combined because both coils are at the bottom of the tank. What you want is for the solar to heat the bottom half of the tank and the boiler to heat the top half of the tank. The Vitocell B-300 is ideal, but it's very expensive. The Metalpres I have has both lower and upper heat exchangers in smooth stainless with double wall. So that's two heat exchangers with two walls each. The only problem I have with the Metalpres tank is it's poor insulation, by summer time I'll definitely have to put more insulation around it to keep the utility room cool. The Vitocell looks like it has lots of insulation. I don't know if the single wall Vitocell will meet code where double wall is required. I would expect the best metallurgy from Veissmann, but that is not considered by the code.

It's great to watch my 4 x 10 solar collector raise the temperature in the lower half of the tank to 120 in the morning, then overtake the boiler input, and during the afternoon raise the whole tank up to 130 or more. And this is in April, in the summer I will have to figure out how to use more hot water!

It's really easy plumbing compared to most of the hydronic systems I see here. Every new house should have a couple of pipes and a conduit run up to the roof just to make it easier to install a collector.

Hot water without using fuel or electricity (or Hydrogen
)! We need more of this.

Brad

hr

Here is an idea

I wrapped my Ford 65 gallon indirect/ solar tank with some scrap InsulTarp. Easy to install, looks nice, and seems to really extend the HW storage during non sunny days.

I used duct screws with fender washers to fasten the IT to the side of the steel jacketed tank.

Already this year I have seen 120° temperatures with one 4X10 panel connected to this tank.

Gotta love solar DHW.

hot rod

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eric legacy

Buderus makes a dulie special order Model SM They also make tons of solar stuff but they do not think The US market demand is enough to warrant bringing it in. Is this true? or is there a big demand?

prm_8

Noel, What model indirects are those?