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Radiant Floor Heating/radiant floor water treatment anti-freeze


Not started yet- have pex bought - starting this spring- planning a shop/ garage- radiant floor- water heater- central Iowa- putting in R-10 slab & footing insulation- R-15 walls R-38 ceiling. no windows- insulated garage & walk thru door. I want to know what % of my water needs to be or ratio of water/antifreeze I need and not hurt the heating abuility of the water- also I have been told to use DISTILLED water in the closed sytem??? true or false?

Here in Minneapolis we rarely use anti=freeze of any kind except when installing hydronic snow melting in a driveway or sidewalk. In this application, where flow will be require in sub=freezing temperatures we use a 35% mix of inhibited propylene glycol for burst protection down to -40F and flow to -11F.

This give you some idea of the requirements of a typical shop or residence.

We premix the anti=freeze and check the pH with a properly calibrated electronic pH meter and the concentration with a properly calibrated refractometer. Distilled or soft water should not be used unless your water is very hard, in which case professional advice should be secured before you commit yourself.

The other factor in any hydronic system is the components and the heat source in particular. There are many types of boilers with many types of heat exchangers. Each manufacturer will have list of appropriate additives and some are very particular about pH and the type of propylene glycol they will allow.

Every year we replace a heat exhanger or other heating system component for lack of maintenance or bad chemistry or both. We use non-toxic chemicals to flush dirty systems and carefully proscribe the right inhibited additives for the particular system we are working on.  

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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