ERV:
In some cases, ERVs may be suitable in climates with very cold winters.If indoor relative humidity tends to be too low, what available moisture there is in the indoor exhaust air stream is transferred to incoming outdoor air.
ERVs also allow the exchange of moisture to control humidity. This can be especially valuable in situations where problems may be created by extreme differences in interior and exterior moisture levels. For instance in cold, heating-dominated climates, better air flow and the introduction of humidity to the indoor environment can help control wintertime window condensation. In humid summer climates which are cooling dominated, it can be critical to dry out incoming air so that mildew or mold doesn't develop in ductwork.
ERV:
In some cases, ERVs may be suitable in climates with very cold winters.If indoor relative humidity tends to be too low, what available moisture there is in the indoor exhaust air stream is transferred to incoming outdoor air.
ERV can dehumidify moisture air during summer time to offload your A/C to keep your house in a comfortable humidity level. HRV will bring in humid air in summer time while add load to your A/C.
Both ERV/HRV are not recommended to run when outside temperature below -25 degrees.
New energy star/R2000 house has no exhaust fan in bathroom and only rely on ERV/HRV to exchange the air. In winter it's Ok but in summer it could be an issue when it's very humid outside.
I will go with ERV next time.