Here is some information on a commercial unit made by a company near here, Research Products. One of the benefits they talk about is humidity control. They refer to this technology as an "Energy Recovery Ventilator". The link to the owner's manual has more a little more detail on the internal works. Here is a link that might be useful: Aprilaire Site

Unvented fireplaces are problematic. I think they are outlawed in Canada and, in my opinion, should be outlawed here because they are dangerous and harmful to indoor air quality. Building codes in many communities outlaw them, especially in sleeping rooms because of the risk of oxygen depletion and/or carbon monoxide buildup. Consumer Reports has a good article on the subject available free of charge in their website. If there is an uncomplicated and not too costly way to vent your gas logs, doing so with eliminate the problem you described. But if you depend on gas logs to provide serious heat, you should consider upgrading to a direct vent system. They are safe and highly energy efficient. Go to the FIREPLACE forum and plug in direct vent in the search engine to find out more about them.

Haha, a lot of guessing from afar. I lived in Santa Mo for many years. I'm a bit north now. I've owned several houses and have done remodels a few hundred miles to the north. But I haven't built any houses. A close friend did a massive remodel of a 3000 sq ft house on the Balboa Peninsula a couple of years ago and I talked with him a lot about what he was doing along the way. But my advice is that of a former neighbor and homeowner, not someone with firsthand experience. I think building to code should be just fine. As for "leaky", no. I wouldn't allow your contractor (or the architect) and their work to be sloppy but I wouldn't worry too much about it. Tell him you're looking for quality work but it doesn't need to be as if it were in the Midwest or East. In the design, be sure to have enough west and east facing windows for cross ventilation. A few opening skylights can be useful to vent out hotter air. A heat recovery ventilator is overkill, you can open windows the majority of the year, even on heating days, as you know. My friend in Newport uses his A/C pretty regularly and he's got the beach one block in one direction and the bay one block in the other. so I think you would use yours too. I don't think having a minisplit unit for 1000 feet downstairs would give you the kind of air circ you'd want to have. I'd opt for conventional heat and A/C, and make sure you have enough return air coverage upstairs, that will be your real cooling target and you need enough ducting and airflow there and back to the hardware for it to work well. Good luck.

If the HP will be your only source of heating I would look at the Carrier Greenspeed over the Lennox. Avoid contractors that only sell one brand of equipment, maybe ask your builder for the contractor he/she uses. HVAC contractors that do builder work are typically much cheaper than the big hvac dealers who sell directly to customers. The prices for the highest efficiency lennox/trane/carrier equipment is likely within a few hundred dollars of each other...if you want a particular brand and the quote is so vastly different find another contractor. I would definitely spend the 650 for the additional zone. The ability to zone off that first floor bedroom will save you the $650 in a relatively short period of time and will help with comfort in the bedroom. HRV is probably a good idea in a new construction house that is very tightly insulated. An alternate would be to use bathroom fans that automatically turn on for a set period of time each day but you would lose efficiency as you would be exhausting conditioned air from the home...I have no idea what the payback time would be on the HRV.