Temporary attachment of loads

[danjayh]

My boiler is situated in a place where I could theoretically use it to provide heat for several occasional loads - for instance, to heat my detached garage for a few hours while I have to work on something ( I have a spare HX + fan unit that came with my boiler), to heat an outdoor pool on cold summer days, and (most recently), to tanklessly heat water to ~150f for use in melting ice dams (I was thinking of stringing together 2-3 sidearms in series to be able to heat ~2-3gpm of DHW ... my boiler is rated for 175,000 BTU/hr, so it should be able to handle it).

My question is this -- does anybody have any ideas on the best attachment system? Since I'd use it at most for a few hours at a time, I'm not real concerned about insulation -- more with having flexible hose. Anybody have any suggestions on hose?

For the actual attachment, I was thinking maybe 1-1/4" camlocks (like they use for firehose). Any other suggestions on that?

Since it's a short-term load, do you think I need to worry about return water temperature?

 

[GENECOP]

Not exactly sure what you describing but why not have valves instead of cam locks.....just build a Manifold, label, and distribute as needed....what do you mean "worry about return water temp"......

 

[Clarkbug]

I would agree with Gene that a manifold might be the best bet so you dont have an accidental release and discharge of hot water. Otherwise I suppose you could find threaded connections you hook up when you needed them to.

Return water temp is definitely something you would want to watch if you dont have something in place currently. Especially an issue for the snow melt on the cold start. Even though its an intermittent load, thats going to be time you may be condensing flue gasses and potentially causing issues... Probably would void any warranty on your boiler also.

 

[danjayh]

When I say 'temporarily attached', I mean something that I can attach when I want to use it for a few hours, and then disconnect to take in the house. I'm thinking I'd use this thing maybe 2-4 times a month for 3 or 4 hours. Think of it like the heat version of a compressed air line - you attach a tool for it when you want to use it, and when you're done, disconnect it and stow it away somewhere.

 

[bmblank]

You'll run into air in the line. I would imagine you'd spend 45 minutes getting this portable hydronic working to hear the garage for an hour. I think an electric heater or just a propane mister heater would be all you need.

 

[Clarkbug]

bmblank brings up a good point. You could permanently install a plate heat exchanger on your loop, and then just connect to the other side of it with your temporary heater. Put a purge tee on the outlet of the Hx, and you could do a fresh fill each time into your temporary lines.

 

[MarkW]

We use hydronic ground heaters on constructions sites and there are closed system quick disconnects that retain the fluid pressure for aux reels that we sometimes use. You'd just put the connections on your manifold and hook the hoses up when needed. Hoses have to be heat transfer hoses, of course. I suspect you'd be running this into a water-air HE? Ground Heater used to have that setup, as well. We never had one, though.
Wouldn't your boiler protection valve be handling any return temp issues?

 

[danjayh]

We use hydronic ground heaters on constructions sites and there are closed system quick disconnects that retain the fluid pressure for aux reels that we sometimes use. You'd just put the connections on your manifold and hook the hoses up when needed. Hoses have to be heat transfer hoses, of course. I suspect you'd be running this into a water-air HE? Ground Heater used to have that setup, as well. We never had one, though.
Wouldn't your boiler protection valve be handling any return temp issues?

My boiler has more than one hot water supply on it, so this would be on its own (newly added) circ pump (there is already a ball valve, so I wouldn't have to drain it)..

 

[maple1]

You might be able to do something. If anything I think would lean to keeping my system closed and adding a FPHX (I think mentioned above) - then using the B side of that to run your temporary hookups to/from. Sounds interesting after a bit of thought - but I would likely permanently pipe in a pool heater, put a stove in the garage, and just run a hose from my domestic hot for the ice dam thing with likely an oversized HX for heating DHW. Or install a tankless coil in my storage tank & do it when burning.

I did use hot water on the back yard rink here a couple times back when I had my old boiler with coil in it - it was neat making all that steam but not sure it contributed much to the ice surface.

 

[MarkW]

I got a 20 plate HE on ebay for $60. Likely less expensive than multiple sidearms. It heats the water as fast as the faucets will flow when the boiler's above 170.

I haven't put hot water on my rink. I just pump water from under the ice. One would think the hot water would help smooth surface before freezing.

 

[Bob Rohr]

I got a 20 plate HE on ebay for $60. Likely less expensive than multiple sidearms. It heats the water as fast as the faucets will flow when the boiler's above 170.

I haven't put hot water on my rink. I just pump water from under the ice. One would think the hot water would help smooth surface before freezing.

I have used Watts Radiant Onix heating hose for temp heat installations. Fairly flexible and very durable, maybe limited to 1" size however.

Plenty of MPH multi purpose hose available at hose wholesalers, Watch the temperature ratings.

Zambonis fill with hot water, they claim it makes for a clear ice?? We supplied solar DHW systems to several ice rinks up in Michigan, trying to go "green"

 

[Boil&Toil]

If that's the only reason Zamboni's use hot water, a vacuum pump would be a lot greener - "clear ice from hot water" mostly has to do with degassing the water as it's heated.

As for the original question here, the main issue seems to be more that (some of) the loads will freeze rather than them moving around - so supply them (as fixed loops) with heat exchangers on the warm side and anti-freeze in the loop. The hot water can simply be plumbed in normally in the boiler room and run (as hot water) in a hose, no disconnecting stuff at the boiler needed. And you can even melt ice dams with "cold" water if need be (it's still 50 degrees or so, normally.) Mostly, ice dams say to fix your insulation and venting so you don't get ice dams next year and into the future.

If you constantly connect and disconnect things, you'll be constantly introducing air, and in 99.9% of boiler systems, that will cause corrosion that you would otherwise not have.

 

[MarkW]

Mostly, ice dams say to fix your insulation and venting so you don't get ice dams next year and into the future.

There is always that.