The systems thatrun your home,compared.
Buying guides for hubs, thermostats, heat pumps, air purifiers, backup power, EV chargers and leak protection, starting with what works with your wiring, your HVAC and the ecosystem you already use.
Plan by system
Each system has its own compatibility questions. Start with the one you are upgrading.
Smart home
Hubs, Matter, switches and sensors
Climate & air
Thermostats, heat pumps, air quality
Power & energy
Batteries, generators, EV charging
Security & access
Locks, doorbells, cameras and alarms
Water protection
Leak sensors, shutoffs and water heaters
Networking & electrical
Mesh Wi-Fi, smart panels and wiring
Installation & interoperability
Wiring needs, pros and warranties
Know before you install
Size an air purifier with CADR: the two-thirds rule, air changes per hour, true HEPA, filter costs and noise, plus why to avoid ozone-producing purifiers.
Backup power compared: home batteries, standby and portable generators, and power stations, by capacity, runtime, transfer method, noise, safety and cost.
Level 2 EV charger guide: circuit size and the 80 percent rule, plug-in vs hardwired, J1772 vs NACS connectors, smart features, permits and panel capacity.
- 04
Matter, Thread, Zigbee and Z-Wave: Which Smart-Home Standard?
Smart-home standards
- 05
Smart Lock Buying Guide: Fit, Security Grades and Connectivity
Smart locks
- 06
Smart Thermostat Compatibility: C-Wires, Heat Pumps and Wiring
Thermostat wiring
- 07
Smart Water Shutoff Valves: Types, Installation and What to Check
Leak protection
Home Systems questions, answered
What is a good CADR for an air purifier?
At least two-thirds of the room's square footage for smoke CADR, assuming 8-foot ceilings. Higher is better for allergies or wildfire smoke.
Read: Air Purifier CADR and Room Size →How much backup power do I need?
List the loads you must run, add their watts for peak power and multiply by hours for energy. A fridge, lights, internet and a furnace blower need far less than a whole house.
Read: Home Battery vs Generator vs Portable Power Station →What size breaker do I need for an EV charger?
The breaker must be rated for 125 percent of the charger's continuous current. A 32 A charger needs a 40 A circuit; a 48 A charger needs 60 A.
Read: How to Choose a Level 2 EV Charger →Is Matter a wireless network?
No. Matter is an application standard that runs on top of networks such as Wi-Fi, Ethernet and Thread.
Read: Matter, Thread, Zigbee and Z-Wave →Will a smart lock fit my door?
Most fit standard US deadbolt prep: a 2-1/8 inch bore with a 2-3/8 or 2-3/4 inch backset on doors about 1-3/8 to 2 inches thick. Check the lock's specs.
Read: Smart Lock Buying Guide →What is a C-wire on a thermostat?
The common wire completes the 24-volt circuit so the thermostat gets constant power. Most Wi-Fi thermostats need it or an adapter.
Read: Smart Thermostat Compatibility →Compatibility before features
Every recommendation is checked against wiring, HVAC type and smart-home platform before features.
Each guide says who the system suits, who should look elsewhere, and what to check before you buy.
Brands cannot buy a review or a spot on a list. Partner codes save you money; they never decide what we recommend.
Prices are dated, codes are updated across the site at once, and pages are revised when a product, standard or rule changes.
The home systems index
- 01Smart homeHubs and bridges, Matter and Thread devices, smart switches, sensors and automation.1 page
- 02Climate & airSmart thermostats, heat pumps and mini splits, ventilation, air purifiers, humidifiers and dehumidifiers.2 pages
- 03Power & energyHome batteries, solar, standby and portable generators, transfer switches, EV chargers and energy monitors.2 pages
- 04Security & accessSmart locks, video doorbells, security cameras, alarm systems and garage controllers.1 page
- 05Water protectionSmart water shutoff valves, leak sensors, sump monitoring and water heaters.1 page
- 06Networking & electricalHome networking for connected systems, smart electrical panels, load management, structured wiring and intercoms.0 pages
- 07Installation & interoperabilityWiring and permit requirements, when to hire a pro, interoperability between platforms, warranties and maintenance.0 pages