Can you dual-wire a house, part AC and part DC?

Lee Watt March 17, 2019, 12:17 p.m.

I have been doing a bit of research lately on solar power, grid-tied and backup systems. As we plan to build a house to Passive House standards, is there any way to get around building it exclusively with AC power systems? I would like to build it with at least the lights running on a straight DC system to prevent waste from the inverter and again at the light source. This would also allow for smaller wire to be ran to the actual light bringing forward some cost savings. Is the National Building Code moving towards allowing people to do this or is it still set for AC power only with plug in every twelve feet?


Responses (1)

Ecohome April 9, 2019, 10:39 a.m. Reply

We have seen that done before so there shouldn’t be a problem with code, but it is still a good idea to check with your local code authority to be sure.

Our two cents - there is for sure losses due to the inverter, but for a load as small as lighting it may not be worth the added effort to wire it for DC, particularly if you use LED lighting. Since you’re going to install an inverter anyiway, it really boils down to the amount of lights you think you’ll need, what that draw is, and how much cost and effort is required to run DC as well.

Please let us know what you finally decide, It’s a great question and a great idea. Best regards.