HVAC cold air returns

Each one of my bedrooms has two cold air returns. One is located near the floor and has a grill that can be opened & closed. The one located near the ceiling is just a grill. I know hot air rises, cold air is heavier, etc. When should the bottom one be opened or closed-summer/winter seasons? ...

Unscrupulous HVAC Technicians often use the symptoms arising from a bad run capacitor or contactor to sell a trusting homeowner a whole new air conditioner. If you have a quality air conditioner and furnace, and properly maintain it, it should last 25 to 30 years. If in doubt, always get second...

What size of cold air return should I use on th ebasement approx 700squre feet two separate room with two heat vents in each 4" will do per room? Thanks

Hi, while changing my old thermostat to a new one I Didn't realize I had the wrong circuit breaker tripped In my home. Turns out that the new thermostat is not Compatible to the wiring in my house(I think) and After hook up there was no power to the thermostat. I Put the old one back on with...

My old lennox hvac transformer blew, it was a Basler be11349rcd29, 120volt to 24 volt 50/60 cycle, it has a white and a black wire comeing from it, I want to add a fuse to the correct line, I don't know much about electric stuff, how or where do I find a correct and affordable replacement part,...