[Greenbuilding] [BULK] Re: Radiant heat boiler--heat exchanger for tiny buildings/families?

[Keith Winston]

Hmm, well, I'm not sure what you mean by automatic. The Grundfos comes 
with a timer that you can set for any number of half-hour periods during 
the day: typically it would be something like breakfast lunch and 
dinner, and maybe bedtime. The advantage to the timer is the water is 
warm when you walk up to the sink, the disadvantage is that you keep 
pumping warm water up to the sink even when no one is using it (the 
water then subsequently cooling in the lines, and starting the process 
all over, and thereby demanding more water heating energy.

A button or a proximity sensor only does the water when you want it, but 
requires wiring that's a little more specific, and/or requires a unit 
under every sink you care about.

Big buildings typically have a full-time recirculation loop. I'm 
inclined to believe that would be wasteful for a house, too much heat 
energy dumped into the envelope (not to mention the additional plumbing 
cost, with no possibility of retrofit). Both the systems above tend to 
use the cold water line as a backfeed for the hot water as it heats up 
(they reverse the flow in the cold line as they charge the hot line). 
Gurndfos also makes a whole-house recirculation pump that must be 
plumbed in during construction (since it requires a full-loop hot water 
layout). You can see it, and the unit I was talking about (Model 
UP15-10SU7P / TLC 
<http://www.houseneeds.com/Shop/plumbing/recirculators/grundfos/grundfosup1510su7ptlcbuypage.asp> 
) and the Chilipepper for that matter here:

http://www.houseneeds.com/Shop/plumbing/recirculators/waterrecirculatorindex.asp

The Grundfos is all over the place. RE Michel has it (sometimes on the 
shelf). It might be cheaper elsewhere. Good luck!

Oh: as someone mentioned, Taco makes an option too. I think they 
actually bought another company, d-mand or something like that. It's 
much like the Chilipepper, though it looks like a pump (the Chilipepper 
always concerned me because whatever hardware it's using is hidden in 
that box -- it looks like an aquarium pump or something. Is it really up 
to pumping for the many accumulated hundreds of hours that one hopes it 
will sustain?). Some of the Taco systems are visible here:

http://www.blueridgecompany.com/radiant/hydronic/428

Note Blueridge, they've got some nice stuff.

Keith


Lawrence Lile wrote:
> Can you give me model numbers on that stuff? Sources of supply?  I need
> to install one system or the other in one location.  
>
> The Chillipepper system uses a manual pump initiation switch.  Why don't
> they use a flow switch to make it automatic?  (Probably someone else has
> the patent on that.)    It sounds like your system could be made to be
> automatic fairly easily.  
>
>
>  
> Lawrence Lile, P.E., LEED AP
>
> -----Original Message-----
> From: greenbuilding-bounces at listserv.repp.org
> [mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Keith
> Winston
> Sent: Monday, February 12, 2007 4:09 PM
> To: Greenbuilder list
> Subject: [BULK] Re: [Greenbuilding] Radiant heat boiler--heat exchanger
> for tiny buildings/families?
> Importance: Low
>
> I am installing a Grundfos that works very similarly, though with a 
> clever twist. The pump sits in the utility room. There is a thermostatic
>
> "comfort valve" under the sink that works like the Chilipepper, spilling
>
> hot water back into the cold line. When hot water arrives, the valve 
> closes, the pump sense the back pressure, and turns off. The clever 
> thing is, you can install as many comfort valves as you want.
>
> The only thing is, the Grundfos has an integral timer, and I think the 
> Chilipepper uses a pushbutton actuator (I installed one years ago). I 
> lean towards a button, but all my clients thus far have leaned towards a
>
> timer. A button saves energy and increases comfort, I'm less confident 
> that a timer saves energy.
>
> Keith
>
>
> Lawrence Lile wrote:
>   
>>  
>>
>> I've been looking into these pumps
>>
>>  
>>
>> http://www.chilipepperapp.com/Default.htm
>>
>>  
>>
>> instead of hot watrer recirc pumps.  Then there is demand in the hot
>> water line, but there is no heat yet, they pump that cold water back
>> into the cold water line, getting the hot water out to the fixture
>> faster, without wasting the water.  Any experiences?
>>
>>  
>>
>>  
>>
>>  
>>
>> Lawrence Lile, P.E., LEED AP
>>
>>  
>>
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>>   
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>
>   

-- 
Keith Winston
Earth Sun Energy Systems
Hyattsville, MD 20781
301-980-6325
send me mail at 
keith at the company below
www.EarthSunEnergy.com