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Radiant Floor Heating/Radiant Panel or Radiant floors?



Am doing an addition and wanted to know what would be best choice if my existing heating source is hot water baseboards.  I have a 100k BTU modulating boiler with 4 zones, the addition will run off the 4th zone.  I have done the DYI manual J calculations and fairly confident the BTU estimates are pretty accurate.  My question is am I better off with radiator panels or radiant pex floors?  Given my other 2 zones are baseboards which require higher temps to run, fuel savings will be minimal if I have to run it at higher temps to get half decent output from the copper fins.

Would it be worth it invest in mix values to run baseboards at higher temps, but much lower for panels or radiant floors?


First, an ACCA Manual 'J' room-by-room heat load analysis.

I am not sure why you are "fairly confident in your "DIY manual J", as I have to tell you, it is usually the first mistake. Mixing hydronic radiation is an advanced skill, read; not easy.

Generally speaking; if you have fin-tube baseboard--the least efficient or comfortable of all the incomparable hydronic heating systems--mixing any other radiation, takes some experience. Still, I have run many sub-floor radiant heating systems with commonly accepted fin-tube temperatures without compromise.

One serious caveat is avoiding micro-zones that could short-cycle the best "modulating" boiler.

With a little professional design help, anything is possible.  

Radiant Floor Heating

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Morgan M. Audetat


Radiant panel heating design, including floors and ceilings, European wall panels and snow melting for residential and light commercial buildings..............................................................-Master of Steam and Hot Water,City of Minneapolis....................................................--- Master Plumber, State of Minnesota...........


30 years..... Charter Board Member - Radiant Panel Association, former manufacturer of condensing boilers, former national distributor of radiant floor products, son and apprentice of mechanical & plumbing contractor. Current mechanical/plumbing contractor specializing in hydronic based, integrated HVAC systems. Radiant floor heating/cooling. Snow Melting. Condensing Boilers. Indirect water heaters. System design, consulting and technical training world-wide. Licensed contractor, designer, installer and consultant.

B.S. University WI 1981 CONTINUING EDUCATION: Viessmann Condensing boiler and Solar water heating certification 2010, N.D.S.U. Lead Worker RRP certification 2010, Knight condensing boiler certification 2009, Wrightsoft Manual J CAD certification 2009, RPA Designer & Installer Certification 2008, Nate Hydronic/Forced Air Certification 2008, Uponor/Wirsbo advanced design school certification 2007, Buderus Wall-hung certification 2007, Power Limited License (low voltage controls) 40 CE credits 2005, Basic Hydronic Certification IPEX & Northern Alberta Institute of Technology 1998, Charter Board Member - Radiant Panel Association 1994, Residential Off-Electric to Hydronic Conversion Heating School Canadian Hydronics Council 1994, B&G Little Red School House 1993, Rood Utilities (now Auburn Technical Institute) Oil Burner School 1993 ,Tekmar Controls residential and commercial 1993, Division Manager and Advanced Hydronic Seminar Instructor for the first Exclusively Hydronic Radiant Floor Distributor in the USA 1990, Hydronic Radiant Heating Association Workshop participant with Richard c. Bourne, PE spring 1988, Master Plumbing, Hydronic, Solar Course Red Rocks Community College 1987.

Awards and Honors
2009 System Showcase Award - Radiant Panel Association

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