advice on running nonpressure loop to heat exchanger in attic

[hokiefan]

I heat with an outdoor wood boiler. I currently use a air to water heat exchanger in my first floor unit, plan to run lines to the heat pump in attic, approx 35 ft rise. Do I need check valves on both lines or just the incoming line. Thinking of adding a pump where I will tee off my incoming lines from the heater to push it up the rise to the attic.
Will the head pressure be enough to push the water out of my OWB?
Any Thoughts?

 

[stee6043]

Check valves will not prevent your boiler from losing water if it's below the attic lines. Not to mention that you can't really have a check valve on the "down" line that would prevent the water from going "down".

Many folks have struggled with boilers installed below their lines in the house. It's a losing proposition almost any way you look at it. Your best bet (but not super efficient) is to have a flat plate exchanger in your basement and run a pressurized loop to your attic from there. Or an open look from the flat plate exchanger with the vent being in the attic.

 

[hokiefan]

Thanks for the info. I hadn't thought of using a Flat Plate heat exchanger. How would I go about sizing the heat exchanger?