[Greenbuilding] [BULK] Re: suspended slab

[rigaziodesigns]

Wow! Thanks all for great insights! And I will search further for older
conversations on the subject. I think this is a "wish list" project for the
homeowner at this point but I wanted to make sure that he thought all this
through before planning for something like this. Any one have a rough idea
on cost for this project? And Keith, if this becomes a reality you will be
hearing from me....

Lisa


On 9/26/06, Lawrence Lile <LLile at projsolco.com> wrote:
>
>
> All valid concerns.  However, the radiant floors I've worked with require
> 140F water, enough to sterilize them well.  Since this is above the safe
> temperature for a regular domestic system, you end up needing a mixing valve
> here with any radiant system at that temperature.  This is the same in a
> direct or an indirect system.  During the summer months, 50F incoming water
> would quickly cool the radiant heat pipes to below any temperature where
> salmonella would be a concern , and constantly flush them out, presumably
> with chlorinated water.
>
> As far as the extra valves to go direct, this consists of a single one-way
> valve. Doesn't take much extra planning, just download a schematic from your
> radiant heat supplier.   Compare the cost of that  one valve to the cost of
> a heat exchanger and extra pump, plus the efficiency of going direct versus
> the efficiency loss of a heat exchanger.  A heat exchanger is far more
> complex than the direct system, and would challenge a DIY'er even
> more.  THere are good reasons to go to a direct system.
>
> Since this comes up every 3-4 months, do a search on this forum and see
> what has been discussed about it before.  Direct radiant heat really is a
> standard way to connect the system, and is done safely quite often.
>
> I'm sure you're not convinced, and wouldn't put a direct system in your
> own house, but take a look at the info that is out there.
>
> Interesting info about the tankless water heaters coupled to a solar
> preheater.  I'm considering this very arrangement, and wonder whether it
> will not work so well.   Even if the tankless loses efficiency, if it is
> made up for by "free" solar energy it might still be worthwhile.
>
> --Lawrence Lile
>
> ________________________________
>
> From: Shawna Henderson [mailto:shawna at abridesign.com]
> Sent: Tuesday, September 26, 2006 11:55 AM
> To: Lawrence Lile
> Cc: greenbuilding at listserv.repp.org
> Subject: Re: [Greenbuilding] [BULK] Re: suspended slab
>
>
> I think the health issue is not so easily shaken off. THe line feeding the
> water heater in a non-radiant floor house comes directly from the well or
> municipal line, at ±45*F. This is not salmonella-breeding condition in the
> line, nor in the water heater. Also, there is no recirculation from the end
> use back into the tank (ew, the thought of it!).
>
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