Proper Boiler Sizing

Larry_7

Recently a co-worker attended a boiler school at RE Michel. At the section on sizing, the rep explained the only correct way to size was by the Manual J and not the amount of radiation. The gist was that radiation needs to be based on the Man J and most older homes have been tightened up, insulated, etc, and now are likely to have more radiation than is actually required. I don't think in the real world any one would remove sections to arrive at the correct radiation unless the rad was severely oversized. From what I've gathered here and through Dan's books, size should be based on radiation as long as radiation is equal to or greater than heat loss. I think I may have used "radiation" too much...or is that possible here?

We have a Munchkin school coming our way soon. Hope I get to go.

Thanks for any insight.

Larry

Mark Hunt

The rep is right. Do a manual J and measure the connected radiation.

Now calculate what water temp you will need with that amount of EDR.

Sizing a boiler JUST to EDR may give you a grossly oversized system. And that equates into HIGHER fuel costs.

If you put a boiler in sized to EDR and the actual heat loss for the home was much lower due to improvements, you COULD actually kill the new boiler. The house will satisfy at lower temp supply water and you MAY shock the living daylights out of that shiny new boiler. And let's not even mention flue gas condensation!!

The new condensing boilers offer a way to capitalize on the improvements the customers have made to their homes.

Take the Munchkin class, we love 'em!!

There are some very exciting products coming out that will fit perfectly into older systems that are in homes that have been "tightened up".

You'll be ahead of the other guys and people will reward your time and efforts with JOBS!!!!

Ain't America GREAT!!!!!

Mark H

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Unknown

If it's hot water

Do a heat loss survey. If it's steam, measure the radiators, too. It's very important to know how much radiation you will need to fill with steam. Noel

c-rex

Boiler Size

IBR has a great heat loss calc. You do that, you measure or count the rad. and somewhere in those wonderful numbers you get enough info to figure out that in the case of hot water, here's agood reson for a re-set control, and in the case of steam, you just gaurenteed yourself that you pugged in a generator that's going to inflate tose raditiors. Old homes, heat losses, upgrades to structures, all great...remember to ask the occupant how the house heats.....Happy trails