I used info online from mrhvac.com. It was pretty detailed, asked about sq ft of outside wall, and roof, type of doors and window as well as thier proximty to the sun. It came out just a hair under 100,000 required. What seems odd to me is that I am heating nearly 5,000 sq ft of home with alot of tall ceilings. My trophy room alone is 1,200 sq ft with 14' tall ceilings. There are other tall ceilings in the house as well. It is a newer home with proper insulation and I live in Winchester, VA, 2 hrs south of Harrisburg, pa. Does this sound light to you guys?
I currently am heated with 2 zones of heat pump with LP back up, I think each unit is a 2 1/2 ton unit.
Questioning BTUH Calc
- mooseman100
- Member
- Posts: 150
- Joined: Sat. Mar. 05, 2011 10:31 pm
- Location: winchester, va
- Stoker Coal Boiler: EFM 520
- mooseman100
- Member
- Posts: 150
- Joined: Sat. Mar. 05, 2011 10:31 pm
- Location: winchester, va
- Stoker Coal Boiler: EFM 520
I used 70 degree inside and 20 degree outside. So maybe a KA-6 would do it and not the KB-8. It will be in an outside shed does that add much into the calculation?
- Rick 386
- Member
- Posts: 2508
- Joined: Mon. Jan. 28, 2008 4:26 pm
- Location: Royersford, Pa
- Stoker Coal Boiler: AA 260 heating both sides of twin farmhouse
- Hot Air Coal Stoker Stove: LL Hyfire II w/ coaltrol in garage
- Coal Size/Type: Pea in AA 260, Rice in LL Hyfire II
- Other Heating: Gas fired infared at work
- Contact:
You just have to plumb it correctly to get that 100 k inside the house. How long a run, what size pipe, etc.mooseman100 wrote:I used 70 degree inside and 20 degree outside. So maybe a KA-6 would do it and not the KB-8. It will be in an outside shed does that add much into the calculation?
Rick
- Sting
- Member
- Posts: 2983
- Joined: Mon. Feb. 25, 2008 4:24 pm
- Location: Lower Fox Valley = Wisconsin
- Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG
ummmmm --- so your targeting a 50 degree temperature rise on the dwellingmooseman100 wrote:I used 70 degree inside and 20 degree outside.
because ......
It never gets colder than 20 in your back yard
I am moving there.
- Richard S.
- Mayor
- Posts: 15243
- Joined: Fri. Oct. 01, 2004 8:35 pm
- Location: NEPA
- Stoker Coal Boiler: Van Wert VA1200
- Coal Size/Type: Buckwheat/Anthracite
That's a big factor , how thick are the walls? If they are 6 inch I could really believe it.mooseman100 wrote: It is a newer home with proper insulation and I live
- Sting
- Member
- Posts: 2983
- Joined: Mon. Feb. 25, 2008 4:24 pm
- Location: Lower Fox Valley = Wisconsin
- Other Heating: OBSO Lennox Pulse "Air Scorcher" burning NG
http://lwf.ncdc.noaa.gov/oa/climate/online/ccd/meantemp.html
The mean temperature (average) for January of the last 30 years in Roanoak VA is 35.8
In Green Bay its 15.6
Now we all know it get colder than 15 in Green Bay and the same holds true in VA -- So my point is if your design temperature rise is only 50 degrees - when it the weather will turn cold and you have evenings below zero - you WILL need a second source of energy to add power to the system. An oil or propane backup or dual fuel will not fail over and help pick up the load. While I recommend under-sizing the solid fuel appliance as you have - because it will operate more of the time at its peek efficiency - you will need some sort of primary/secondary or series boiler configuration where they both can run. And they may both have to run as much as 100 hours a season, with this low a calculation.
Now that written -- if your using a negative 20 not positive 20 and calculating your design load up from 40 degrees colder -
Thats a nice house!
The mean temperature (average) for January of the last 30 years in Roanoak VA is 35.8
In Green Bay its 15.6
Now we all know it get colder than 15 in Green Bay and the same holds true in VA -- So my point is if your design temperature rise is only 50 degrees - when it the weather will turn cold and you have evenings below zero - you WILL need a second source of energy to add power to the system. An oil or propane backup or dual fuel will not fail over and help pick up the load. While I recommend under-sizing the solid fuel appliance as you have - because it will operate more of the time at its peek efficiency - you will need some sort of primary/secondary or series boiler configuration where they both can run. And they may both have to run as much as 100 hours a season, with this low a calculation.
Now that written -- if your using a negative 20 not positive 20 and calculating your design load up from 40 degrees colder -
Thats a nice house!
- steamup
- Member
- Posts: 1209
- Joined: Fri. Oct. 03, 2008 12:13 pm
- Location: Napoli, NY
- Stoker Coal Boiler: Axeman-Anderson AA-130, Keystoker K-6
- Hand Fed Coal Boiler: HS Tarm 502 Wood/Coal/Oil
- Coal Size/Type: pea, buck, rice
20 btuh/sq ft is reasonable for a very well insulated newer house. However, do not cut yourself too tight with solid fuel device sizing, as they are slower to respond.
ASHRAE Weather Data indicates at the 97.5% design dry-bulb is 10 deg. f. for Winchester. This means on the average, the temperature is at or above this temperature 97.5% of the time. If you use this temperaure without a safety factor, your heating system will struggle 2.5% of the time on average.
I would re-run the calc using 10 deg. f. Make sure you have a safety factor in the calculation for pickup, piping losses and unforseen such as extreme weather conditions. For an outside shed and piping to the structure, I would add and additional 15 to 20% above this number. The shed will be toasty warm.
I would not go less than a K-6 and might consider a K-8 for that amount of sq ft. Consider the K-8 if you want to indirectly heat your Domestic water also. With that large of a house, you must have several bathrooms.
Be careful in planing the piping between the shed and house. You will need more than one single pair of 1" lines.
ASHRAE Weather Data indicates at the 97.5% design dry-bulb is 10 deg. f. for Winchester. This means on the average, the temperature is at or above this temperature 97.5% of the time. If you use this temperaure without a safety factor, your heating system will struggle 2.5% of the time on average.
I would re-run the calc using 10 deg. f. Make sure you have a safety factor in the calculation for pickup, piping losses and unforseen such as extreme weather conditions. For an outside shed and piping to the structure, I would add and additional 15 to 20% above this number. The shed will be toasty warm.
I would not go less than a K-6 and might consider a K-8 for that amount of sq ft. Consider the K-8 if you want to indirectly heat your Domestic water also. With that large of a house, you must have several bathrooms.
Be careful in planing the piping between the shed and house. You will need more than one single pair of 1" lines.