Websites for HVAC technicians.

Our rough rule: if the unit is under twelve years old and the repair is a few hundred dollars, fix it. If it is past fifteen, the heat exchanger is cracked, or the repair costs more than a third of a new system, replacement almost always wins on running cost alone. We show you the numbers for your unit and let you decide — no scare tactics about carbon monoxide unless there is an actual reading.

Cold-climate models do, and they keep useful capacity well below freezing. Most homes here get set up as a hybrid: the heat pump carries the shoulder seasons and mild winter days, and the gas furnace takes over on the coldest nights. We run a heat loss calculation on your house before recommending a size, because an oversized heat pump short-cycles and an undersized one leaves you cold.

It is not based on square footage alone, whatever the last quote said. Insulation, window area, ceiling height, orientation and duct capacity all change the answer. Oversized equipment cools the air without pulling the humidity out, which is why some houses feel clammy at 22 degrees. We size it properly, once.

A one-inch filter every one to three months, a four or five-inch media filter roughly annually. More often with pets, shedding kids or a renovation in the house. A blocked filter is the single most common cause of the no-heat calls we get in January, and it costs five dollars to prevent.

A furnace or AC changeout is normally one day. A furnace-and-AC pair or a heat pump conversion is one to two. We do not leave a house without heat overnight in winter — if something unexpected turns up mid-install, we get temporary heat in place before we go.

Often yes, particularly for heat pumps and high-efficiency equipment, and the programs change every year. Some require pre- and post-install assessments in a specific order, so tell us before you book anything. We install to the program's requirements and file the paperwork with you.