[Greenbuilding] Radiant heat/DHW for a 400 SF in-law unit - recommendations?

[Keith Winston]

Okay, now that I've gotten to look at it: the Phoenix appears to be 
EXACTLY a Polaris water heater (though I'm not sure the Polaris are 
modulating, but modulation doesn't seem to me to be nearly as important 
in a tanked unit?). Plus, what POSSIBLY makes them a "Combi" unit? The 
sketches they provide seem to indicate the DHW going to the fan coil or 
convectors directly (they seem to miss a pump in those diagrams), and 
then use the X-Pump Block for the Radiant (at least they aren't using 
DHW in the radiant! I don't really like DHW in the fan coils/convectors 
either, in principle -- what keeps water from sitting there for 6 
months, then flushed into the tank and drank [drinked? drunk?] or 
showered with?).

I really don't see why these are called Combi units. The Polaris costs 
almost $3000, it's a very nice very high efficiency condensing gas WATER 
HEATER which people regularly use for radiant floor apps... with the 
addition of a heat exchanger, pumps and other things that I would expect 
to be part of the package with a Combi unit. But what's the definition 
of Combi anyway? What makes this something other than a very efficient 
water heater? Now, if it comes in significantly under $2000, I might 
find some use for it...

Keith



Alchemy Construction Inc wrote:
> Your welcome.
> The x pump block runs around $800-1000 bucks.
> The tapings on the radiant side fit Uponor ( formerly wirsbo) 
> manifolds exactly.
> You get two pumps, a heat exchanger, air elimination, and water 
> temperature control with an outdoor reset.
> The Radiant Mixing Block is the same less heat exchanger.
>
> It's funny that Heat Transfer Products doesn't have their new water 
> heater on their site but take a look here:
> http://www.jtgmuir.com/manufacturers/phoenix.html.
>
> If you have a hard time locating these products to purchase e-mail us.
> Sincerely,
> -- 
> Stephen Bohner
> Alchemy Construction Inc.
> www.alchemyinc.com
> 707-822-8013
>
>
> Keith Winston wrote:
>> Thanks! Now, I imagine the X-Pump Block by Taco is pricey, because from 
>> the description it uses their fancy integrated-controller pumps, which I 
>> got a $500 quote on when I checked when they first came out (for an 007, 
>> comparably priced below $100 in it's normal version). But I'll be very 
>> interested in seeing what they go for, assuming my local plumbing supply 
>> houses stock them, or I can get them easily. They would be really 
>> convenient...
>>
>> Well, the Phoenix does sound interesting -- the tank, modulating and 
>> condensing is potentially a good match for solar, although it's not 
>> on-demand, is it?. Do you know where I can find technical information on 
>> it? I've spent 20 minutes or more searching, which is a lot of time for 
>> something that really ought to be obvious (that is, a hot new product 
>> like that). Maybe they just haven't quite hit the streets with it? 
>> Thanks again for drawing my attention to it.
>>
>> Keith
>>
>>
>> Alchemy Construction Inc wrote:
>>   
>>> http://taco-hvac.com/en/products/Radiant+Systems/products.html?current_category=61
>>> The x pump block controls water temperature by either a setpoint,  
>>> Delta T or outdoor reset.
>>> The Radiant Mixing Block does the same without the heat exchanger.
>>> Both Include air elimination.
>>> Not a big marketing push by HTP at the moment but their new Phoenix 
>>> water heaters are Modulating /condensing water heaters.  PVC vented, 
>>> thus low exhaust temps. High efficiencies with the added benefit of 
>>> tank storage to fully tap solar harvesting and micro zoning, while 
>>> able to handle sustained flue gas condensation all day long, unlike 
>>> flash heaters.
>>> The new Takagi TK3's must be vented with Stainless venting along with 
>>> the Noritz line.  I'm guessing they are addressing sustained flue gas 
>>> condensation problems......
>>> Sincerely,
>>>
>>> -- 
>>> Stephen Bohner
>>> Alchemy Construction Inc.
>>> www.alchemyinc.com
>>> 707-822-8013
>>>
>>>
>>>
>>> Keith Winston wrote:
>>>     
>>>> I imagine you're talking about the double-pumped-flat-plate-exchanger in 
>>>> a package by Taco? Is it called an X Block? I've just started seeing 
>>>> them listed, never seen one -- what do they go for? That pre-packaged 
>>>> stuff tends to be expensive... Of course, the time savings... You 
>>>> directed us to the Taco site, but I couldn't find what product you were 
>>>> pointing out (you just gave a general address). What does Taco call it?
>>>>
>>>> Why do you say that about the Phoenix? I can't see what it has that's 
>>>> new? Nor can I find hardly any information on the web: apparently it's 
>>>> made by Heat Transfer Products, the Munchkin manufacturer, but they 
>>>> don't list it on their website. Phoenix also makes a rather 
>>>> standard-appearing oil tank water heater. I just don't understand why 
>>>> this has come up twice in 2 days, is Phoenix doing a big marketing push 
>>>> right now or something?
>>>>
>>>> Keith
>>>>
>>>>
>>>> Alchemy Construction Inc wrote:
>>>>   
>>>>       
>>>>> An X Block tied to their hot water heater or
>>>>> an X Block tied to a solar hot water tank or
>>>>> or an x block tied to a new Phoenix water heater.
>>>>> that's in order of pricing hot water heater being cheapest
>>>>>
>>>>> The x block works great for smaller heating loads.
>>>>> http://www.taco-hvac.com/
>>>>> The New Phoenix water heater is going to fill a large hole in combined 
>>>>> hydronic heating.....
>>>>> Sincerely,
>>>>>
>>>>>   
>>>>>     
>>>>>         
>>>>   
>>>>       
>>
>>   
>

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