Adding Tank to Tankless for wood boiler

[plusorfive]

Okay, so I decided to go tankless with a Navien natural gas tankless whole home water heater. It works fine and has no recirculator. I now want to add a outdoor wood furnace since I have tons of free wood sitting in my backyard. The sales guy said the best way to heat the water is to get a tank in the system to hold hot water. So, I am planning to buy an electric 50 gallon water heater and add that to the system so I won't be using the On Demand in the winter months. Two questions...

1. Can a person have the tank of hot water feed the intake of the tankless? Then the tankless would not have to use little or any fuel.

2. Can a person install the tank and somehow bypass the tankless with a shut off valve? And can the tankless just sit unused for 5-6 months of non-use?

Any ideas?

 

[IFIXH20]

Usually when a storage tank is used with a on-demand system it's a small one
(10 gallons) and it's installed on the back side of the tankless. If it's energy your are trying to save why not drop the temp setting on the tankless in the winter.

 

[chukar]

Keep in mind when your talking about heating water there are two styles of heating water depending on your purpose.

*When your using a boiler for heating your house, or pool, your boiler may vary the amount of BTU's based on the incoming water temp; so if there is a 5°f difference between the water entering the boiler and the water leaving the boiler, it may fire at half power. Now if say there is a 15 or20°f difference that same boiler may fire at full power.

*when your using a Navian for heating drinking and bathing water your system will regulate based on the amount of water flow, not incoming water temp. So if your running 1 faucet it may run at 20% power but if you have 2 showers and the laundry running it may fire at 80% or 100% power. It's based on GPM flow rate.

So even if your preheating the water your Navian measures how much water it's heating not what the incoming temp of the water is. Most heating boilers are not setup for straight domestic water, normally you need an heat exchanger in between to separate the drinking water from the heating water. Keep in mind in your using a wood boiler outside you may have to have an antifreeze chemical in the water incase the power goes out or has other issues.