New To Radiant - Looking For Guidance

DaveABC

Hello, I am new to radiant heating and plumbing in general. I've done some research and came up with the design below. I figured I'd post it for others to help. I'm at the initial stages. I can post my house layout if there is discussion or interest that starts. Thanks ahead of time for feedback. Please tear my design to pieces so I can make it better. Once the functionality is refined I'll work on the placement and optimizing space.

UPDATE:
This is an image of my updated plan. I deleted the original.

Zman

Don't use an open system. DHW and heat should be separate systems.
Do not use tankless water heater as boiler.
Most radiant systems require primary secondary piping.
PRVs should be as close to the boiler as possible.
Always perform heat loss calculations prior to design.

lchmb

use mixing valves on your zones to help control a balanced temp out after doing what Zman said. An open system is just trouble waiting to happen. You could use a good boiler with indirect and with proper setup get very high efficiency out of it..

Rich_49

Forget everything you believe you have learned to this point . Let's start over . Where is this building located , what type fuels are available , what type of construction is the home ?

Once these important things are established we can all help you with a best practice plan while hopefully keeping it within a budget or your budget . This posted plan is a disaster , using wrong ideas and equipment . A room by room heat loss should be first in the process . Others may recommend an online calculator for this .

DaveABC

Based on this link I performed a heat loss calculation for the house. I came up with 36,670 BTU/H for a 1,300 sqft home in upstate New York. I was looking into the NCB-180E Combi-boiler by Navien. It's an older home being retrofitted.

Based on the feedback, I'm looking into doing a closed system for the radiant heating and also domestic hot water with this heating unit. Not sure if this would work.

Also hooking into public water and natural gas.

Zman

Nice work.
The Navien would be a good budget choice that will not take up much space. It will short cycle a bit with 3 zones, you might consider consolidating zones.
I would install it with zone valves and a single circulator like the drawing attached. A grundfos alpha circ would be appropriate.