Correct Boiler

Markit05

Hi new to the forum. I have a question about sizing a boiler for my home, nat. gas baseboard hot water. I thinking of replacing in the spring. My first question is how to understand the numbers posted on these boilers and the second one i was looking at Peerless boilers. My home is approx. 1600-1700 sqf total, build in the fifties, split level design, in Jersey. Home has had no remods at all and i dont think there is much by way of insulation the exterior walls either by what i saw. Any help and thoughts would great. The Peerless model i was looking at #ME-i-05 sprk wpc. thanks……… paul

EzzyT

When it comes to sizing your boiler you want a room by room heatloss analysis to be performed to ensure that the right size boiler is chosen for your home.
From my experience performing many Heatloss analysis’s a house from the 50s and at 1700 square feet your most likely looking at a total heatloss of 40,000 btus. But definitely can me even less then that. Where in NJ are you located?

pecmsg

hire @EzzyT

You can’t go wrong.

jesmed1

@EzzyT sounds like his estimate is right on the money, so you won't need a big boiler.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/199854/correct-boiler

I could not help but notice that your house changes by about 100 square feet, Paul. Is this hourly or daily or maybe monthly? How ofter is to a full 1700 Sq Ft, and how often is it 1600 Sq Ft? In most cases where I find houses that change that much I try to select the average size and pick a heater that will do that size, like in your case, I might select a heater that will heat a 1650 Sq Ft home.

I hope this helps.

Intplm.

@Markit05 A reputable installer will do what is called a heat loss calculation as mentioned above to help size the boiler to the requirements of your home.

This will involve taking measurements of each room, including the size of and the type of windows and doors, the type of insulation, if any, and to verify if the amount and size of heat elements…radiators are adequate.

This is done to help find the most properly sized boiler for your home. And for that matter, your comfort.

GroundUp

+1 for the heat loss calc. With that said, baseboard has a maximum BTU output of <600 BTU per linear foot. If you simply add up the footage and multiply by 600, the boiler will not need to be any larger than that.

Markit05

i revised my original post with a model#. To EzzyT Woodridge township.

EzzyT

@Markit05 your just a couple of towns away from me. Whenever you’re ready to replace the boiler you can contact me at (201) 887-8856.

RTW

Dear poster:

Not yet mentioned, but in response to the house being built in the 50's, it was common Not to insulate the homes back then, so you're in good company ( or bad company). I know there are programs in MA for example, that subsidize the installation of "cellulose insulation"

RE: "@Markit05 A reputable installer will do what is called a heat loss calculation as mentioned above to help size the boiler to the requirements of your home."

Here is an explanation on the insulation commonly added these days:

Cellulose insulation is a plant fiber used in wall and roof cavities to insulate, draught proof and reduce noise1. It is primarily made from recycled newsprint23. The insulation material conforms to most spaces without disturbing the structure or finish2. Cellulose insulation is a type of loose insulation made from post-consumer recycled paper content3. It is considered to be one of the most environmentally friendly insulation materials available4.

If heat loss is a consideration in sizing boiler, you may want to factor in added healthy insulation if that's being considered

Id steer clear of chemically developed "foam insulation" that contains formaldehyde - and who knows what else - that is known to emit cancer causing fumes, but do what you like

All the Best

Regards,

RTW

EdTheHeaterMan

@EzzyT will be better at selecting the new boiler's size based on the conditions that exist at the time you need to replace the boiler. That said, if your home has an insulation upgrade before you need to replace the boiler, that would be better than if you purchase the boiler, then upgrade the insulation/windows/doors/ and other energy saving measures.   Doing that stuff after you own the new boiler will most likely make your new boiler oversized.  Just a thought. 

EBEBRATT-Ed

Most 50s houses had around 2-2 1/2" in the wall and 4" in the ceiling

Kaos

Even a best ManJ has to make a lot of assumptions for an old structure such as yours. Since you have existing heating use, the best way to size a new boiler is by doing a fuel use calculation.

The rough calculation is to take your wintertime fuel use in therms and multiply by 40. So if you use 1500 therms during winter, your heat load would be around 60000BTU. For more accurate numbers you can run through the math here:

https://www.greenbuildingadvisor.com/article/replacing-a-furnace-or-boiler

Any improvements you make, will reduce those numbers, but it would give you a max sizing as a starting point. Since this will probably be bellow the the smallest boiler out there already, it won't change selection.

hot_rod

And if you go with a modulating boiler you gain the ability to “right size” it, and condense part of the season for 90% efficiency