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Old 03-21-17, 10:11 PM   #5
DEnd
Apprentice EcoRenovator
 
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Quote:
Originally Posted by buffalobillpatrick View Post
Much more heat is lost along the outside perimeter and close to doors & windows than than in the center of the heated space.

A good strategy is to place more pex in those areas, such as 4" On Center vs. 8-12" in the center etc.

Any ideas on how to apply some science to this?

Yep. And conventional wisdom is wrong, sort of.

First of all you need to understand what you are actually doing.

Naked People Need Building Science

Radiant based HVAC

So what exactly is the HVAC system doing? In reality it is not warming or cooling the air to warm or cool you it is warming or cooling the surfaces of the building. Those surfaces either add or remove heat from you. In all actuality to be comfortable those surfaces have to remove heat from you, If they do not remove heat from you fast enough then you will be uncomfortable, as will removing it too quickly.

The good news is that your wall assembly (as described in your other thread) will likely have very little heat loss so an even floor temperature will likely keep your walls warm enough, as the walls will be absorbing heat from every other surface in the room. Closer tubing spacing will likely raise the response time of the system, But it likely isn't needed.

Last edited by DEnd; 03-23-17 at 03:44 AM..
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