I think i've almost got my decision..but what if i'm wrong and even with all the research i did on here, the house doesnt like it and it's undersized. (id probably choose 1 size lower then my guy choose for me)

Is there a market for used boilers? Plus id have to pay someone to uninstall/reinstall another one since i dont do any of this work at all.

i'm assuming my dealer would laugh at me if i wanted to exchange it even if i had my receipt

 

Hardly any market for used boilers. People practically give them away.

 

zoinks! I guess 'gently used' isnt one of the headings in the local paper Just reinforces i'm doing the right thing taking my time and finding out all i can before i buy.ty

 

I think you should buy a Burnham MPO84, and when you find out it's too small for your home, I'll give ya $50 for it, but only if you deliver it. If I have to pick it up, I'll do that for 20 cents a mile, or you can deliver it. It's about 180 miles. Deal ?

 

Get a blower door test, then you might be able to say that. Come back and tell us what it was and what your revised heatloss is.

 

already did it last week..waiting for my 400 dollar report as we speak

i did play with some numbers on my own after i found out i only had r11 in 1/2 the attic. cranked it up an additional r19 but i think it only cut the loss about 5K from what i recall

 

Only? Only?! Why would you blow that off? You've now spent a good couple weeks querying and reading this site. By now you should understand that Job #1 in planning and replacing a heating system is to understand the building heat loss and get the load down.

Let's do some crude math that shows how much that poor attic insulation is costing you over an entire heating season. It is a LOT. For a very crude example....

Say a typical heating season is 8 months. That's 5760 hours.

Say over the course of the heating season the average heat loss of the present attic is 2500 BTU/hr more than if you had it well-insulated.

5760 * 2500 = 14,400,000

That's 14.4 million BTUs.

Heating oil produces about 139,000 BTU/gallon, and you burn it in an appliance that's 85% efficient, for a net of 118,000 that goes into heating (ignoring other losses along the way).

14.4 million / 118,000 = 122 gallons.

Say a gallon of oil costs $4.50.

122 * 4.50 = $549.

If you think that $549 doesn't matter, then just send it to me.

If you are in the Northeastern US, your attic should have at least R38. And before you go running off to the local building supply, read this about how to seal up and plan for insulation. As an energy-saver, this stuff is a DIY no-brainer.
http://www.energystar.gov/ia/partner...e_May_2008.pdf

 

thanks for thee wonderful example..u should frame that..it's really demonstrative and drives home the point

I should also state that i havent seen the space under the attic floor myself...the blower test guy just told me he could look under my floor from the side/exposed part of the attic and see that there is just r11 in there and i'm ASSUMING there is space under my floor to put the r19 to bring it up to the level of the other part of the exposed attic. I do realize you canNOT crush insulation so if i dont have the space under the floorboards, obviously crushing insulation would be stupid and foolish for me to do/add.

but your example also points out something good for me. I'm worried about oversizing BUT even if i do buy too big a unit, insulating will help reduce the effects of oversizing. I know it's preferable to get the exact size you need. But it's nice to know even if it's a big bigger, i'd still realize 'some' savings

oh crap, i just realized something and now have to go back and redo my entire heat loss. My mold inspector recommended my crawlspace be insulated with r30 and a 3 or 6 vapor barrier.

i'd imagine R30 on the floor will really seal up the house good and so back the the slantfin program! heck i may have zero heat loss by the time this is all done!

thanks again for being patient with me...this is happening at the worse time of my life..going thru a divorce...and i just found out that if i had gotten this inspector in one month ago, he could testify that i need 100K of work done on my house and thus making it unsaleable and that i wouldnt have had to pay my wife a dime for the house..so i'm really pizzed off about my mistake

 

wow did i screw up my heat loss figures ive been using all along. I dont know why, but before i had an insulated floor down. I do not have that currently.

at 0 degrees here goes:

So putting in the uninsulated floor my heat loss is 125K, which is right on the mark for the LV110 boiler i was narrowed down to.

redid heat loss adding 6 inches insulation in the crawlspace for when the mold guy does it and it got down to 108K!

is that really an accurate decrease for that amount of insulation? wow if so

edit:
and at 10 degrees the insulated loss is only 92K...geez...i further confuse and confound myself

 

The rate of heat loss is dependent on the difference between the inside temperature and the outside temperature. If you raise the outside temperature (or lower the inside temperature) the rate of heat loss drops. This is why night setback works and is also why you want to use the average lowest winter temperature rather than the 100 year record lowest temperature in your heat loss calculation.

Using the average lowest temperature in calculation the size for the boiler and heating system means that when that 100 year cold snap hits (generally only a few days at most) your heating system might not be able to attain the design indoor temperature but it will only be a few degrees colder. The difference between 68 degrees indoors and 72 degrees indoors likely won't be felt if the outside temperature is minus 20.

What will be felt is a lower fuel bill for all the time it is warmer than that 100 year low.