So, what you are saying is that homeowners have asked for transformers that can be mounted outdoors? That may be but I am not sure there is that much customer feedback in the transformer marketplace from homeowners. I ended up buying a transformer that is rated for being mounted indoors or outdoors and mounted it indoors mainly because I had feeds going 3 sides of my house and the conduits were aready installed into the house. There were very specific requirements for installation of the transformer indoors such as clearances, mounting on non-combustible surface, etc. What puzzles me is what in the construction of a transformer would cause it to be hazardous to be mounted indoors if it was only rated for outdoor use. To me, it seems only the clearances required around it for heat dissipation and being mounted on a non-combustible surface and not near a combustible surface would be the main requirements for mounting indoors. Can anyone shed light on this? What exactly is different about an outdoor and indoor transformer that limit where it is installed (other than a rating that says "Don't do it" from some agency)? (no pun intended)

they help save electricity by using a transformer that converts higher voltage electricity into a 12 v energy efficient electrical current. Sorry to say it's not quite that simple. First of all, there's nothing magical about a transformer. Watts are Watts. With an ideal transformer, watts in would be exactly equal to watts out. But in real world transformers, watts in > watts out - always - because of the transformer's losses (inefficiency). So all other things being equal, a transformer wastes electricity. The evidence for this is that it gets warm. Heat == waste. But things aren't always equal. When you're talking about low intensity incandescent lights, a low voltage lamp can be (though it isn't always) more efficient than a line voltage lamp. This is because its filament can be operated at higher temperatures for a given light output. This is often the case with xenon undercabinet lights for kitchens, for example. I may have missed some, but regrettably I've never seen any landscape lights that appear to operate this way. Every incandescent landscape light I've seen has been a low output (and thus low filament temperature) lamp. So I doubt that you gain much, if anything, by using a transformer. There's also the greater losses in the wiring caused by the higher currents. By Ohm's law, current = voltage / resistance. So, for a given wattage, at 12 volts the current is 10 times as high as at 120 volts. The only real advantage that low voltage landscape lighting has over line voltage is relative ease of installation. That said, low voltage landscape lighting is a good application for LEDs. Even though they're not as efficient as their reputation would suggest, they're usually more efficient than dim incandescents. They're also right at home with low voltage. As a side benefit, they usually last much longer than incandescent lamps.

Update on the transformer and dimmer issue. The retailer sent a 60 Watt transformer to test with an ELV dimmer instead of the magnetic one. It's tiny, smaller than the dimmer and much cheaper, like $65 instead of $200 for the 150 Watt transformers. We got the package via UPS on Monday (not Next Day Air when sent on a Friday) and the lights worked fine but the dimmer did not work. The transformer was installed in a wall space near the ceiling. Today they disconnected the transformer and installed it all a different way, with the transformer installed behind the dimmer/electric box. It all seems to work with the exception of one bulb that won't fully dim. I'm just glad we have lights finally. They will install the kitchen lights once the additional 3 transformers arrive, which should be tomorrow.

Not sure if I am reading it correctly? Did you say he set it up so the heat pump shuts off when the emergency strip heat is on? I have done tons of research as I am replacing my system. In the "old" days people didn't think a heat pump could produce heat below 20-30 degrees. The modern heat pumps can produce heat in very cold temps. They won't be able to heat your house completely if it is below zero however it will still provide some heat and help out. With a new system I don't think you should ever shut your heat pump off unless it is physically not working for some reason. I know when I first moved into my current house a tech told me to shut my heat pump off because temps were close to 15 below zero. When I got up the next morning it was only 59 degrees in my house with the stat set at 65 degrees. (my strip heat is undersized). I turned the heat pump back on and it was back up to temp in a couple hours. It will produce some BTU's at those temps.