Heating Help

30,000Btu heat load oil boiler

@ October 23, 2010 10:16 PM in 30,000Btu heat load oil boiler

I've come across a low temp, 2-zone, in-floor radiant system that used to run on an oversized Brad-White thermal mass type oil burning tank. Its probably been short cycling for years and it began leaking from the tank. The owner wanted it removed and now I'm considering what to replace it with. The heat loss calc we came up with shows 30, 000Btu heat load with a design temp of 28F (Seattle area). That's a very low load and I'm wondering if anybody has ideas on an efficient oil boiler design for that small demand....The piping is existing although I can change it inside the mechanical room. I was thinking a conventional Buderus 115 and piping it primary / secondary except won't this be oversizing the boiler once again? How do I manage such a small load?

Flat plate heat exchanger instead of buffer tank

@ December 29, 2009 9:34 PM in Modifying Takagi Jr to handle radiant heat

Would the right pump control combined with a flat plate HE (or a Taco x block) work at all or do I have to have the thermal mass of a buffer tank? I could set the delta T between the system side and the heater side so that the heater pump cycles instead of running continuously...It looks like the X block handles this easily but again, do I just have to have that thermal mass? 

Squeeze a nickel

@ December 29, 2009 12:03 PM in Modifying Takagi Jr to handle radiant heat

spend a dollar....Thanks. A buffer tank it is.

Modifying Takagi Jr to handle radiant heat

@ December 29, 2009 9:29 AM in Modifying Takagi Jr to handle radiant heat

I'm looking at a Takagi Jr, NG unit that is now providing radiant heat for baseboard rads. The problem is it's efficiency, lack of it, because as long as there is a call for heat from either of the two t-stats the circ pump sends flow through the Takagi (and then through a two way zone valve) and as long as there is flow through the unit the burner is firing and the flue fan is on.
I'd like to add a high/low limit that switches the takagi  off but allows the pump to run as long as the t-stat calls for heat. This would include a 20 degree delta T, switching the Takagi back on once the temp in the primary loop drops to the lower temp. I'm thinking creating a cycle will lower the gas bills and electrical. Anybody have ideas of a good way to do this if this is the way to go? I'm thinking Honeywell aquastat...

Takagi

@ December 14, 2009 1:46 PM in using tankless water heater instead of boiler

Yeah Nick a Takagi Jr is what I'm thinking of installing. I'm wondering what your flue vent set up is, if its direct vent or not, straight out the wall or vertical through a roof etc. Also what your pump/zone valve distribution is. I'd be adding this on to an existing 3/4" baseboard system. I'll take any info you've got, thanks...

using tankless water heater instead of boiler

@ December 13, 2009 4:34 PM in using tankless water heater instead of boiler

Anyone have opinions/experience using a tankless water heater as a heat source for hot water radiant instead of a boiler? How well do they compare? If for example an NG on demand tankless has a NG 19,500 Btu input to 140,000 Btu input does that mean it could handle heating a house with a 120.000 Btu design load? Do they operate too inefficiently over time to make the lower up front cost not worth it? etc...

whirling dervish yo

@ December 7, 2009 7:32 PM in boiler retrofit question

Great answers fellas! I can work with this. 

hot water

@ December 4, 2009 4:09 PM in boiler retrofit question

so if its a hot water boiler retrofit onto an existing system you should do a heat loss calc?

boiler retrofit question

@ December 4, 2009 1:21 PM in boiler retrofit question

When retrofitting a boiler and none of the heat emitters are changing, then you size the boiler to the Btu capacity of the existing emitters, in this case baseboard radiators...is this correct? It doesn't make sense to do a heat loss calc because the emitters are staying the same. This seems pretty straightforward or am I missing something?

Maintenance Contract

@ September 30, 2009 2:43 PM in Maintenance Contracts

I'm a provider...plumbing & heating contractor. I want to service the systems I install.

Maintenance Contracts

@ September 29, 2009 5:51 PM in Maintenance Contracts

I want to set up maintenance contracts for boiler and solar systems. Anybody have any advice/experience with these types of contracts?