Sting wrote:is the outdoor temp probe on the north side of the dwelling?
Sting wrote:Out of the direct sun?
Sting wrote:exposed to the wind chill?
Sting wrote:Is the wire broken that runs from the probe to the ecm?
Sting wrote:Did you install the system?
Yes, but my Brother-In-Law helped and is the instructor for the Maine Oil Dealers Association and knows radiant floor heating systems well
Sting wrote:Is the radiation matched to the load?
Yes, every pex loop is controlled by a flow control valve and is dialed in to get a 15 degree drop in temperature from entering my concrete slab to exiting; the number he told me what I needed. No loop is greater than 200 feet in length. The circulators are also three speed circulators for greater control.
Sting wrote:Is 100 degree water the design temp for the radiation to carry the load - or did the last guy just pick that number in the lottery?
He told me 100 degree water was the default temperature for -10 degree weather or below.
I talked with another radiant floor expert this summer and he said my metering system is not needed, and that I can actually program my Munchkin Boiler to do everything that metering pump does (but he did not call it a metering pump, he had some other name for it. Basically it is the circulator that takes the water in my main boiler loop, and gets it down to the target temperature before going into my concrete floor loops). But he said when I get my coal/wood boiler installed, I will need it to drop down my high temp water so I should keep it for now.
The only other thing about my house that is different is that under my concrete floor, I have 400 tons of rock for added thermal mass isolated from ground temperatures by insulation.