Heat Loss Calculations

[Northwoodsman]

I recently used the heat loss calculator at [email protected] to calculate the heat loss on my 2,300 sq. ft. home. This is a pretty simple program and I'm curious as to how accurate it is. Based on a 70 F indoor temp. and 1 F outdoor temp (it only lets you calculate heat loss at 70 F indoor and 1 F outdoor) it says my heat loss is approx. 80,000 BTU/HR.

Does this figure sound reasonable? Does anyone else know of another (or a few) heat loss programs that I could run my calculations with to verify this figure?

Also, does anyone know what the required factor would be to calculate heatloss at a different outside temp (1 F is not the norm and thus as the outside temp. went higher the heat loss would go down)?

Finally, I plan to use my new EKO 40 and 1,000 gallon storage to heat my domestic hot water and 390 gallon hot tub. Does anyone know what the approx. heat demands are for these 2 items?


Thanks for your help !

 

[Nofossil]

I recently used the heat loss calculator at [email protected] to calculate the heat loss on my 2,300 sq. ft. home. This is a pretty simple program and I'm curious as to how accurate it is. Based on a 70 F indoor temp. and 1 F outdoor temp (it only lets you calculate heat loss at 70 F indoor and 1 F outdoor) it says my heat loss is approx. 80,000 BTU/HR.

Does this figure sound reasonable? Does anyone else know of another (or a few) heat loss programs that I could run my calculations with to verify this figure?

Also, does anyone know what the required factor would be to calculate heatloss at a different outside temp (1 F is not the norm and thus as the outside temp. went higher the heat loss would go down)?

Finally, I plan to use my new EKO 40 and 1,000 gallon storage to heat my domestic hot water and 390 gallon hot tub. Does anyone know what the approx. heat demands are for these 2 items?


Thanks for your help !

80,000 BTU seems a bit high, but not irrational if you have a lot of window area. SlantFin has a heat loss calculator as well There are links scattered throughout the forum. Might be interesting to see how they compare. In my experience, most old-school calculations tend to err on the side of too high a loss figure. If you get an oil boiler that's too big and install too much baseboard, you'll never know and the supplier has made a bigger sale. If you choose something that's too small, they'll make a smaller sale AND have a cold and unhappy customer.

Hot tub load depends on where it's installed, how good the insulation is, and what your climate is. An annual heat load of around 1000 BTU/hr is typical, but winter load could be more like 3000 BTU/hr.

I heat a 550 gallon tub as a zone on my wood boiler. Works fine.

Typical domestic hot water consumption is around 60,000 BTU/day. However, there's a lot of advantage to having a fast recovery time when your DHW tank gets cold. DHW tanks can present a short-term load of 100,000 BTU/hr or more.

I have an EKO 25 heating DHW and a hot tub - there are schematics and explanation on my site - link in my signature below.