Because some Tesla owners have complained about their vehicles not heating up in cold weather, the automaker has issued a recall that it says will address the issue. Over 26,000 Model S, X, 3, and Y ...

A heat pump functions as a typical air conditioning system in the cooling mode — absorbing heat from indoors and rejecting it outdoors. In heating mode, the coils reverse their functions. The outdoor ...

In zone valve setups, a separate zone valve is installed in the pipe to or from each zone. In most installations, the zone valves are in the returns, where the water is cooler. The cooler temperatures ...