I know zip about electricity.  Some building automation companies offer self-powered (by the motion of the switch or small solar cell) wall switches that send a wireless signal to a receiver/switch that is wired into the wire supplying electric to the load.

Perhaps a whole home with these would be better sealed due to having about much less conduit (no physical switch legs) to conduct cold or allow air to blow around the house in, and having fewer penetrations to air seal (assuming some percentage of the seals will fail, thus with fewer total seals needed there will be fewer failed seals).

On the other hand, it's been pointed out that the receiver must always be on to listen for the signal from the wall switch and that when the load is on, these solid state switches have on-state-losses (this is a link to one of the most commonly used types of receivers but my untrained eye doesn't see power consumption specs... http://www.illumra.com/Products/Rec..._copy.html ).  So this would be like a whole house full of small vampire loads (receivers for lights, blinds, smart-outlets...).

Does anyone have a feel for how the thermal gains weigh against the electrical losses?  Assume two identical smart homes with geoexchange HVAC (to drop gas out of the equation and make everything electric) in Northern Zone 5a (use heat about half the year). Will the house with the wireless switches use LESS electricity because the lesser electricity the heat pump uses due to better air sealing outweighs the receiver vampire loads (always listening and on-state), MORE because the use by the vampire loads outweighs any decrease in heat pump work due to better sealing, or would the differences be NEGLIGIBLE?  I think the question in equation form is ((receiver listening vampire load + receiver on-state vampire load)*loads in each room)) vs. ((less conduction + less convection + fewer joints to seal)*the same number of loads)).

I would not start by comparing penetration benefits since that depends, some designs have zero, it and it would be very difficult to determine a cost savings based on a electrical contributions to say blower door test results. Have you ran the cost saving's to compare hard wire circuits that could be replaced by wireless? That would depend on the design too but you could get an idea if you have one?

Wow- that's really putting a fine point on it! Properly built, the differences would be really small. You'd have to overcome the increased cost of the wireless system, not to mention repairs in the future. Hard wired stuff is pretty bullet proof, and very simple to fix. As an example, we had a 'smart' system for our front door light, which was both a pain to program, and then it died after a couple years. The ROI certainly wasn't there. Theoretically, the wireless stuff should save on installation cost, though.

It's an interesting comparison; sort of like comparing which uses more energy- paper plates, or regular ones that you use heat, water, and soap to wash. In the end, though, the differences in the lifestyles of the families in the two houses would have a far bigger impact. Meanwhile, here in SC they are still slapping together R-13 walls out of 2X4's.

I was in CA last year at a home show seen some company offering some wireless products, but nothing that would wire an entire house. It be great for structure like sandwich construction or homogeneous mass walls. Just recess the fixture, done. I know the Swedish build an internal wire chase out of 2x's as mainstream construction. We in the USA like running it through insulation and ruining it and 2x4 studs. I like to see a large wireless transformer at the main power terminal from a source (grid or non)....then have receiver outlets, switches, hard wires, etc and get a way from toxic PVC romex and all the codes that go with wires. It take down labor and inspections. Just not sure about all the frequencies running around.

Posted By Gordon on 28 May 2014 11:30 AM
...Perhaps a whole home with these would be better sealed due to having about much less conduit (no physical switch legs) to conduct cold or allow air to blow around the house in, and having fewer penetrations to air seal (assuming some percentage of the seals will fail, thus with fewer total seals needed there will be fewer failed seals)...

In residential construction, conduit is rarely used for anything other than the service entrance conduit.  Interior wiring is generally done using Romex (Type NM cable) which doesn't need or require conduit.  I would say that most light switches in a home are on interior walls where there is no insulation.  The only potential source of air leakage with wiring in interior walls is through the hole drilled in the top plate or bottom plate to feed the wire to/from the switch.  These holes are easily air sealed with flexible caulk or foam.

I'm just curious as to where the wall switch gets its power from? You need power to send a signal, so it would either have to use a battery, or have wiring going to it anyway.

I too have the same question from where the wall switch gets power from?

We have used Verve wireless switches mostly for log cabin builds. The switches interact with a central control panel that is hard wired to each light or outlet circuit. Just the act of pushing the switch generates the required electricity to send a momentary wireless control signal to the control panel.

http://www.vervelivingsystems.com/