help with boiler sizing

[docgogo]

I have a gw 100 need help with sizing a unit i am in discussion with greenwood about the size of my boiler in an earlier post someone asked if i was undersized well not a good question to most men but guys i need help.
Heres what i have a 1750 sq. ft. poorly insulated home built about 1920 plaster and lath walls lots of single pane windows etc. 100,000 btu heat exchanger in a forced air furnace.
about 800 sq. ft. of basement with 100,000 btu heat exchanger to heat the basement
350 gal hot tub
clothes dryer used a small 6x6 heat exchanger
talked with a central boiler dealer from rio grand ohio said i needed a 500,000 btu furnace
greenwood only makes a 300,000 btu furnace
by this time i no longer trust my installer he is a very nice guy but...... not real knowlegabble about greenwood
a gasification system was important to me secondary to i live in the city with lots of trees around ( like living in the woods)
also heat hot water with a sidearm at the present but will probably go with a plate heat exchanger. the distributer said they would probably exchange for a plate exchanger. ( what size should i use from 40 gal electric tank with three people on 14 yr long showers. )
i really appreciate all the help in advance.

 

[BrownianHeatingTech]

1750 square feet? In Kentucky? Your 100 is oversized. I don't care how bad your windows are. That would be oversized (or maybe just at the right size, if the hot tub and such are pulling enough additional heat) up here in NH.

Joe

 

[docgogo]

i can't keep my temps up when heating both hot tub and the house especially when it get below 20 degrees.
If i only heat the house and dhw i can keep temps up to around 170 deg range.
When i try to heat both i come home after about 9-10 hrs. to pipes that are 80-90 degrees. takes about 2-3 hrs to get back up to temp.
thanks doc

 

[BrownianHeatingTech]

i can't keep my temps up when heating both hot tub and the house especially when it get below 20 degrees.
If i only heat the house and dhw i can keep temps up to around 170 deg range.
When i try to heat both i come home after about 9-10 hrs. to pipes that are 80-90 degrees. takes about 2-3 hrs to get back up to temp.
thanks doc

Oh, you definitely have a problem, but it's not that the boiler is too small.

Joe

 

[docgogo]

Well i need all the help i can get.

 

[wdc1160]

You obviously have a method to test your pipe temps. Find where the return water is loosing temp. 2-3 hrs to get back up to temp seems a little sloooow.