Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Theory question on hydronic radiant
I think I've hit a wall in my understanding of hydronic radiant heating (it wasn't a long climb up).
I have a (very) basic understanding of the formula:
GPM * Delta-T * 500 = BTU/Hr
So, for example, for any given environment, a 1 gpm flow with a 20* F temp drop means that 10,000btu/hr is being released from the water.
Or, a 2gpm flow with a 10* F temp drop also means 10,000btu/hr is being transferred.
I understand that I can control the flow rate (and the water temperature, which appears to not be a variable in this formula).
And I think I can control the temp drop by using different types, sizes and lengths of tubing, putting the tubing in a metal track, etc. (That's about the extent of my knowledge of these variables.)
I am, however, totally confused about what happens to the heat (the BTU/Hr) once radiated from the tubing.
That is, I have 1/2" hepex in tracks, spaced 8" apart under a flooring of about 2.5" of wood (call it r 3.5). Underneath the tubing is mineral wool (I think r 15) which separate the conditioned from unconditioned space.
From what I gather, that means that the vast majority of the heat is going up through the wood floor assembly.
My question is: If, for example, 10000btu/hr is being radiated, and r 3.5 is above and r 15 is below, does that mean that the vast majority of the heat will be radiated into the living space above? Or, will some of it somehow be lost because of the wood flooring assembly?
That is, if the tubing were above the floor (exposed to the air in the living space above), but with r 11.5 below, would it heat the living space equally (or better)?
- 115.1K All Categories
- 82K THE MAIN WALL
- 2.6K A-C, Heat Pumps & Refrigeration
- 38 Biomass
- 396 Carbon Monoxide Awareness
- 2.8K Thermostats and Controls
- 1.5K Domestic Hot Water
- 4.1K Gas Heating
- 102 Geothermal
- 145 Indoor-Air Quality
- 2.5K Oil Heating
- 37 Pipe Deterioration
- 627 Plumbing
- 4.5K Radiant Heating
- 342 Solar
- 12.7K Strictly Steam
- 44 Water Quality
- 568 Buy, Sell, Barter
- 29 Industry Classes
- 62 Job Opportunities
- 11 Recall Announcements