product recommendation for very small radiant load

Marc K.

I'm a heating contractor looking for ideas for what to use for a very low load (under 10,000 btu/hr) radiant job.  Efficiency is important.  I've been thinking about things like the Polaris or Phoenix water heaters, but they're really up there in price, similar or even more expensive than hi eff. boilers.  Anybody have good ideas for less expensive, yet efficient options? Without going into details, I can't use the existing water heater with a hx. I don't want to use a lousy water heater, but I really can't see having my client pay a ridiculous sum for the Polaris or Phoenix. The fuel is LP gas.

NRT_Rob

your choice

high efficiency will never pay back.



so they pay more to "be green", or they take a pragmatic stance and use a regular water heater with an HX, which will run about 75% efficient or so in a heating application.



don't even think about a tankless: it won't help the efficiency out much, if any.



Or you go electric.

HEATHELPER327

electric option

Laing makes a small self contained electric boiler which is very effective at handling small zones for either heating or floor warming.  They have a 2kw model as well as 6 kw models.  Check it out.  I believe it to be a better option than a water heater.....

Gordan

Is there an advantage to doing it that way...

...as opposed to simply using electric resistive radiant mats? If you're heating with electric resistance, wouldn't it be cheaper and simpler to cut out the hydronics, especially since the mats pretty much come with zoning included?



With hydronic you'd have the option of changing the heat source later - are there any other advantages?

HEATHELPER327

options are why to choose hydronic

Utilizing hydronic heat as opposed to electric mats allows the user to add or modify their radiant system more easily as they might find the warmth and comfort of radiant systems a growing need.  they may eventually want to add enough radiant to sustain a more elaborate system.

Mark Eatherton

Advantages...

The advantage of hydronics, is that if you spring a leak, you can find it and fix it. If you break a series resistance element, basically, you up the creek without a paddle, and you have no heat.



THe disadvantage of hydronics is the upfront costs. Pumps, pipes, valves, etc that would not be necessary with a mat type electric resistance heater.



That said, my recommendation would be to go with the brass screen, parallel resistance heater. You can drive nails/staples into the screen and it doesn't affect it. It still needs insulation below the heat source.



ME

Royboy

and those are made/sold by ???

the brass screen, parallel resistance heater, that is ...



google failed me using that description

Mark Eatherton

The Heatison....`

http://www.heatizon.com/radiant-heat-zmesh.php



ME

Royboy

interesting stuff

looks pretty lo-tech and versatile



you could hang some as curtains in front of those electrified windows ... ;-)