Residential snow melt piping

Clayton Armstrong

Weezbo, Thanks for the reply! I will be using a Ultra 80 boiler. All of my low temp zones have between 14,000 and 18,000 BTUs load each. The indirect water heater will be a 40 gallon Gold Plus. The first snow melt zone is 44,000 Btu's and the second snowmelt zone is 50,000 BTU's hence forth requiring "one at at time operation". As I mentioned all low temp zones have secondary heat sources so a prolonged interruption of low temp zones for snowmelting is really not a problem, besides 5 of the 7 zones are in a concrete slab of an extremely well insulated home. The piping for the primary/secondary low temp zones and the indirect water heater pose no issue for me, lot's of expierience there. Just trying to figure out the most logical way to incorporate the snow melting piping into the rest of the system. Wondering if the injection pump is the best way to supply the brass plate heat exchanger, can't get it through my head why it wouldn't be. But I am a rookie at snowmelting who is greatly apprecative of any guidance.
Clayton (Sweetwater)

Clayton Armstrong

Residential snowmelt boiler room piping

I am installing a residential Hydronic system with 7 low temp zones,a indirect fired water heater (prioritized) and 2 zones of snowmelting that will need to be operated one zone at a time because of my Ultra boilers capacity. I have secondary sources of heat in all areas so a significant interuption of heat to the low temp zones while suppling the snow melt is not an issue. I am using a primary/secondary method of piping for the low temp zones but am wondering about the following issues.

Is using an injection pump to feed a brass plate heat exchanger the preferred method for snowmelting?
Can the circulator that pumps to the water heater also be used to pump to the loop (incorporating zone valves) that the injection pump pulls from to supply the brass plate heat exchanger? Or would it be better to use only circulators and flow control valves.
And finally where could I secure some piping diagram examples that incorporate low temp, indirect and snowmelting for residential? Your reply is greatly appreciated!
Clayton

Weezbo

it is a lot of variables Clayton.

i am off to wotk finally so someone else will likely be of more assistance. the thing is though you might want to give them a clue as to the size of some of the emmitters ,snow melt being a real good place to start,then the radiant low temp zones and the indirect. rotational loading and prioritzed controls help in the redistributing of BTU's buh there are limits. some large emitters and heavy mass may take longer to ramp and require additional heat source/s to deliver satisfactory heat to maintain comfort. Buffertanks can do a good job to bring on line additional heat ...i have to think you may need to give a bit more information to help fill in the blanks as it were. for the dollar there is a real crafty computer program that will allow you a variety of what ifs and howboutits. Look under Hydronic CAD 1.0 and look at the offerings by the same author of books and hydronic designe programs...Good luck .

www.hydronicpros.com

S Ebels

Snow melt load?

How many btu's / sq ft are you figuring for your snow melt?
Those don't sound like very big areas for snow melt. 300 to 400 sq ft? How are you proposing to run the slabs controlwise? If you are letting them go cold and turning them on only when snow has accumulated you could be looking at 12-24 hours before melting is complete depending on your btu/sq ft loading and the amount of snow. That's a long time for no heat or hot water in the house. You can't fudge snow melt loads, you either have the horsepower or you don't.

Clayton Armstrong

snow melt loads

Thanks for the reply! Design calls for 124 BTU's per square foot, my boiler sizing and intended operation(zoning) should allow me to easily provide 150 BTU'S if necessary. You are correct as both snowmelt zones (sidewalks and dog kennel area) are approx. 300 square feet and will be operated only as needed. 1" styrofoam is placed under all slabs with 1/2" onix spaced on 6" center. It was figured as a beefed up Class 1 snowmelt. Perhaps I have alot to learn but I was not figureing anywhere near the time element you have eluded too, however with secondary sources of heat through out the structure that does not pose a problem. I am open to suggestions regarding control, one slab is completed the other is not. I was thinking simple controls such as a timer, most winters the usage is rather limited with 20 degree outdoor ambient temperatures present when use is required. However control of snowmelt is an area I would dearly love some input based on expierience as well as the piping arrangement. Thanks!
Clayton (Sweetwater)