electric baseboard calculation

[carrierman]

without going into a detailed HVAC load calculation, I know there is a rule of thumb calc that we use to size electric baseboard heaters in a residence, soo many watts per square foot. House in question is 100 yrs old and is being remodeled. It will not be a high end remodel and insulation is minimal about r-11 in walls at best. Baseboard is wanted by customer to supplement his heat pump which is not quite large enough. Can anyone help me out with that rule of thumb calc?

 

[stevebea]

without going into a detailed HVAC load calculation, I know there is a rule of thumb calc that we use to size electric baseboard heaters in a residence, soo many watts per square foot. House in question is 100 yrs old and is being remodeled. It will not be a high end remodel and insulation is minimal about r-11 in walls at best. Baseboard is wanted by customer to supplement his heat pump which is not quite large enough. Can anyone help me out with that rule of thumb calc?

10 watt per sq. ft.

 

[laketime]

try this

http://www.cadetco.com/rec_watts.php

 

[Denis]

whatever it is, double it if outside temp is below 20

 

[carrierman]

thanks for the responses. Very helpful including the website address given. Our winter design temp here in Delaware is 15 degrees

 

[ptonsparky]

Remind your customer that insulation will pay for itself, not counting the comfort value.

 

[Dennis Alwon]

If you are supplemented a heat pump then you won't need 10 watts/ft.sq. IMO, probably half that is fine. Around here, NC, I used to use 7 watts/ft sq. for stand alone baseboard heat.

 

[ptonsparky]

Is this an older heat pump? They had cooler supply air temps and a reason heat pumps had a bad name for years.

Turning the additonal heat on may cause the ht pump to turn off, costing even more dollars.

Are the elements in the back up heat working properly?