Will Toyo 128HH handle this in peace?

CraigHimselfTH

The question here..... Is it foolish to put energy into designing this system?


theoretically the lil toyo boiler can pull this off but at 120F???

5K Btu heat loss in each unit
25 feet of base board to heat each one
also supply hot water to each unit's point of use electric tank
all the while running outdoors with some 50 foot runs to the end buildings

Jamie Hall

The Toyo OM-128HH is a very nice on demand oil fired water heater for domestic hot water.

It is NOT a boiler. It is not intended for space heating. It should not be used for space heating.

Forgive me, but the concept -- so far as I can understand it -- has a very half-baked look. For the domestic hot water, it would have just enough capacity for one bathroom -- not five -- so unless the usage type is really strange (this looks like perhaps a five cabin resort or something of the sort? The kind of cabin motel I remember from the '50s? Nothing wrong with that...) it won't have the capacity to handle the domestic hot water needs.

This needs a rethink...

CraigHimselfTH

Maybe Toyotomi is trying to trick me

Their installation instructions show the little 128HH doing all these things

Jamie Hall

No, that diagram works --but it's not much like yours. One critical element in there is the flat plate heat exchanger. And then the pumps. And the expansion tanks.

However, that it will work isn't the point. The point is, is it the right tool -- and the answer is no, for heating, and not big enough for five cabins of domestic hot water.

CraigHimselfTH

the real question here is:

Is running heating tubes outside between 5 buildings a bad design to begin with?

All would be pex tubing insulated and buried 5' with the entrances into each building in insulated conduit

Each building would theoretically have 2 domestic water lines and 2 heating water lines coming in through an insulated conduit.

So with a different brand boiler is this a prudent path to pursue???

Or the alternative is

Each unit gets a toyo 300 air heater and an electric 12 gallon hot water heater?

mattmia2

It is certainly possible to use on boiler and run buried heating lines between buildings. Where your frost line is and if the buildings are always heated will have a big effect on how difficult this is.


If the hot water is just for hand washing it might make more sense to just have a small electric tank in each building. You will need to either have a dhw tank in each building or a separate recirculating dhw system that serves all the buildings. I don't think you will eve recover the cost of the additional controls in energy savings using oil over electric for that you would need to heat the tank with the domestic heating water.

CraigHimselfTH

Thanks for the insight Matt,

One great thing you Brough up is these units will be nightly rentals so the heat might be a little Low when not in use, then when people show up and crank on the heat from 55 to 75 if it doesn't heat up in 45 minutes they'll be a little peeved...

Each unit has 2 sinks, a shower and toilet

I think one of the motivators for central DHW is,
if the boiler keeps a 100g sidearm storage tank of hot water warm in the boiler room for a thermal mass and also sends hot water to refill the little point of use tanks, there should only be the line volume to the point of use tank to clear = (1 gallon calculated) before hot water 120f is refilling the tank.

Also the DHW will be wrapped and insulated with the heating lines.

mattmia2

If there is a shower in each unit then an indirect heated by the heating mains probably makes sense. That is probably safer than trying to keep a dhw recirculation system hot enough and maintained to prevent legionella.

kcopp

keep it simple... use the space heaters and install a decent electric WH. 12 gallon will not work for much other than a handwash sink. a 28 gallon w/ a mix valve would do.

CraigHimselfTH

I think you’re right. Maybe I’ll put a boiler in the middle unit for laundry and keep diesel air heat and electric hot water in each unit.