We are at the framing stages of a custom home in North Texas and are looking at the options for a/c and heat as we are trying to get US Green Building Council LEED's certification and efficiency is a consideration. Total cooling capacity needs is between 10-12 tons.
We are considering the 4 ton residential variable refrigerant units from Daiken or Mitsubishi. The Mitsu is the S Series. The Daiken compressors are RXYMQ48MVJU. On the domestic front, we considered the Carrier hybrid system with 21 seer compressors.
Here are the questions we are trying to get answers to before finalizing the decision:
1. What are the differences in efficiency between the systems?
2. What is the availability of parts look like between the two foreign companies?
3. How well do they produce heat when there is an extreme change in ambient temperature and how cold is the a/c? Dallas ambient temperature can drop from 70-30 in one winter day and can go from 60 to 100 plus in the summer.
4. Any other differences that we should consider?
5. Any experience integrating the systems with whole house automation?