Venmar HRV modificationn

I have a constructo 1.5 HRV that is about 15 years old. Ideally I should have gotten an ERV but at the time I was told only the HRV was recommended for my area (Ottawa, Ontario, Canada). Well it has worked fine for all these years except that obviously I cannot use it in the humid, hot summer months for air exchange and during the winter it drops the humidity in the house to a level that the humidifier cannot add enough moisture to get it up to 30% at times. And ERV would be ideal to solve this problem.

I contacted Venmar and there is no ERV switchout core that they supply and were not willing, due to legal concerns, to help me find a product that they had to modify to work with my current unit. I understand that.

So, is anyone aware of a product, either from Venmar or other, that I could switchout the HRV core to make and ERV core? Or is there something else I could do to resolve these summer / winter problems?

Serial #: starts with 9R and was installed in 2000.

thanks,