Welcome to gardening in AZ and to this forum. We hope you'll post a lot, and often. :) I moved here from Seattle in 2000 and absolutely love it here, gardening included. You've gotten some great suggestions for sure, so let us know what you select and how it works out. My north facing walls get sun in summer and shade in winter. I've had great luck with red "yucca", Hesperaloe parviflora, good ol' Aloe vera, and African "ocotillo" (not at all related to our native ocotillo, but it does look sort of similar), Alluadia procera. Good luck and let us know who the lucky winner is and how it does. There are some great local gardening books that are great resources, along with this forum of course. :) Post often! Take care, Grant Here is a link that might be useful: My garden pics October 2011

Air source heat pumps don't make sense in areas where winter temps frequently fall below 32 degrees. Once you get below freezing, you will be running the auxillary heat a lot. If you decide to go the air source route, you will want a second stage gas fired auxillary heat. I live in the mid-atlantic region in the mountains and selected GT. That choice was coupled with a blown cellulose insulation package. My other choice was a propane heat/electric AC with a foam insulation package. Both options were roughly the same install cost. Both would have provided similar energy efficiency. At the time we selected, propane was 3.75 a gallon and rising (with no end in sight) so we went with GT. The delta cost for the GT system (above the cost for a HE propane heat and electric AC system) was $15,000 for the heat pumps and loop plumbing (including pumps) plus $17,000 for digging the pit. The pit excavation should not have cost as much as it did but it is a 12 ton system and the hole was gigantic (120' x 48' x 6'). We live on a mountain and hit a bunch of boulders that required special equipment to get out. Rocky soil also required a 1' base of stone dust to cover the loop piping. The total cost for the GT HVAC system including all ducting was $50,000 plus the pit excavation cost of 17K. It is a large investment and I would only recommend it if you plan to live in the house a very long time. My heating bills are great - maybe 300 dollars maximum a month during peak winter for an 8500 square foot home (5900 living and the rest a condiitoned but unfinished basement). Make sure that whatever equipment you choose can be maintained by more than 1 very qualified HVAC company who has many years of GT experience. In my area there is only 1 GT company who has over 20 years of experience but I am stuck with them for maintenance. There have been times when I wanted to fire them but cannot. Local competition is a good thing. Also - if you build a tight home make sure that you consider ventilation and dehumidification in the HVAC design. I wound up adding both a whole house dehumidifier and energy recovery vent after we moved in becuase we had basement moisture issues as well as stale air in the winter. Tight homes are great for energy efficiency but can create health issues too. It is easy to deal with as long as you plan for it. Good luck with the build.

yes slowing the speed will most certainly affect the whole house cooling and heating. But it may be an easier and less costly option to try first before going to the mess and expense of adding in retrofit dampers. If you haven't done so already, see if some of your individual room vents can be closed off somewhat. Closing them on the lower level may help force more cooling upstairs. Is there a problem with the heating being uneven, or just when cooling? If it is really only with the cooling, then the solar heat gain from upstairs windows and skylights is probably what is the source of the problem. Additional window coverings can make a difference to reduce solar gain, especially on east/west glass.

Most of my citrus get only about 4 to 6 hours of sun in summer. I don't usually have them in full all-day sun. They seem to grow better in pots for me this way. For my situation the pots would overheat too much in all-day full sun. And I've never had a problem with blooming and fruit production. Usually they start blooming before I even set them out. I start them out in shade in spring and gradually -- over a period of 3 weeks -- move them to more sun. I do this because usually they have a lot of tender new growth before I even set them out. Actually toward September/October I do move them to as sunny and protected spot as possible because I want to make the most of the shorter and cooler days. Also want fruit to ripen.