I've stumbled through several hours of very painful calculations with some onlne calculators and been left more confused and less confidant in the results than ever. Who has a (hopefully free or at least reasonably priced) calculator that can assist me in sizing.. 1- ASHP size for 3 1/2 season heating and cooling 2- Electric resistance requirements; room by room, so I can still have heat (although at only 1;1 COP) when the temps get below the ASHP bottom end (I'm in zone 7 P9N0E7 Canada). My plans are nearly finished and I need to draw up electrical plan.

Have you tried Borst engineering . Com? They have several calculators free for personal use. They have very detailed instructions...

Yes thanks..I have tried the Borst heat load calc and at the risk of seeming stupid....

I struggled with it and wonder if there is an easier to use calculator that provides accurate results...I've got to settle on one calc and go with it.

What did you have problems with? I have spent quite a bit of time playing with those calculators as our house design and heating plant ideas evolved, perhaps I can help. Sailawayrb posts on this forum, she is the author of the calculator, so she may also chime in...

What exactly did you have difficulties with when using our heating loss analysis calculator? We always welcome constructive suggestions for improving the function and usability of our free DIY calculators. So please don't hesitate to make such a request to customer support via our website and we can often make such improvements very quickly.

No matter what heat loss analysis software you use, accuracy is more dependent on the user than on the actual software used. A competent heat loss analyst can often accomplish a more accurate/realistic analysis using just a pencil and paper than the average contractor can accomplish using the best ACCA certified software.

Perhaps you don’t like having to first manually determine the total R-value of the building assemblies before entering these values into the calculator? If this is the case, perhaps you might prefer using another calculator that uses a drop down menus for determining and entering the various common building assemblies. If so, you might want to try Cool Calc which can currently be downloaded for free:

Cool Calc

Perhaps you are not comfortable with all the math (e.g., determining R-values, areas, perimeters, volumes, etc.) associated with accomplishing this heat loss analysis. If this is the case, than perhaps you might want to consider hiring someone competent and experienced to perform this analysis for you. If so, we would highly recommend looking for someone who is licensed in your jurisdiction to perform this analysis.