solar hot water

Big Ed

........ run the solar in series with the indirect ,with the solar being first ,then the indirect. Also shut down the electric back up of the solar if rate is high.

lenny_4

how to integrate an indirect with solar

I have a customer that i am installing a new boiler with hydro air and panel rads. The house at the moment has an 80 gallon solar hot water heater with electric back up. is there a way that i can install an indirect off the solar and use the boiler as back up?
Looking for some suggestions and any info with drawings. THanks

bigugh_4

Yes,

> I have a customer that i am installing a new

> boiler with hydro air and panel rads. The house

> at the moment has an 80 gallon solar hot water

> heater with electric back up. is there a way that

> i can install an indirect off the solar and use

> the boiler as back up? Looking for some

> suggestions and any info with drawings. THanks

Constantin

Two typical ways to approach this...

... if money is no object, a large tank with two coils is probably your best bet. The upper coil is used for the indirect circuit, the lower coil is used for the solar "pre-heating".

Given that you already have a fully-functional solar tank, I'd pipe the two in series as shown below. Put in a pump with an internal check valve or an external one and a goldline or similar controller to activate the pump whenever the tank in the indirect is colder than the solar tank.

This way, you maximize the efficiency with which the solar tank is heated and minimize the heating that the indirect tank has to do. Also, given the wide swings in possible solar output, I would install a thermostatic mixing valve between the hot water supply in the house and the indirect tank to keep things safe.

Also, if the cold water piping has a back-flow preventer (as it should), don't forget to add an expansion tank to ensure that the safe working pressures are not exceeded on hot, sunny days.