Hydronic duct coil & radiant system with oil boiler and indirect water heater

bob eck

customer building his own home.

I want to sell him a Trio oil boiler with a indirect water heater.

He is installing two H/P units and putting in hydro duct coils as back up heat.

Plus working on getting him to install radiant in basement and garage and use the radiant to warm the floors in the master bathroom bedroom and in the kitchen where there will be tile.

I was looking at using a 60 or 80 gallon indirect water heater with two coils.

One coil heats the domestic hot water the other coil is used for the duct coils and radiant heat.

Does HTP or another company make a dual coil indirect water heater?

Where do I get info to design this type of system.

Thanks for your help Bob Eck

SWEI

HTP, Crown, and most of the usual suspects offer dual coil indirects. Sometimes they call them solar tanks.

Any reason you can't just run the coil off the boiler? ODR works quite well for hydro-air, though the low end of the curve is quite different than that for RFH. It's more like that for finned baseboard.

Firecontrol933

For purely curiosity reasons, could you elaborate more on why you have chosen this type of design?

njtommy

Also try Heat-flo.com they make a ton of different tanks and are very well insulated.

http://www.heat-flo.com/index.html

bob eck

The boiler being used has very little water volume. I can take the two duct coils and the indirect water heater zone off as high temp temp zones and I thought getting the lower temp zones from the water temp in the indirect trough the second coil would be better and help keep the boiler from short cycling on and off when the smaller zones call for heat or to warm the floors. Any thought on doing it this way?

njtommy

How much room do you have to work with? wouldnt be a bad idea to use two tanks. One buffer and one indirect.

bob eck

New construction home should have room for boiler and two tanks.

SWEI

The oil boiler shouldn't condense anyway, so a reverse indirect (Turbomax, Ergomax) would be a perfect fit here. Control the boiler using a sensor in the tank well, then put a mixing valve with ODR on the hydro-air coil and let the fan run nice long cycles.