The First Heat Pumps

[fqp25]

When did the first heat pumps hit the market? Did they use a regular T-stat, with a separate reverse switch?

Had to show a client and his "Know-It-All" Realtor, (or should I say had to prove to the realtor) that todays house was just a gas furnace with a very old and very big outdoor AC unit. But it did make me wonder what were the first heat pumps like.

The ones I see are all newer, and usually have a digital/programmable T-stat.

Frank

[inspector57]

They were already in widespread use back in the late 70's and used two stage mercury vial thermostats when I went through A/C school. Still pretty new, but I worked on a few that were already at least 5 years old.

[Jim Katen]

Originally posted by fqp25

When did the first heat pumps hit the market? Did they use a regular T-stat, with a separate reverse switch?

Had to show a client and his "Know-It-All" Realtor, (or should I say had to prove to the realtor) that todays house was just a gas furnace with a very old and very big outdoor AC unit. But it did make me wonder what were the first heat pumps like.

The ones I see are all newer, and usually have a digital/programmable T-stat.

Frank

Carrier, the same guy who invented the air conditioner in 1902, invented the heat pump in 1926. It had no practical application at the time because conventional heating fuels were so cheap.

I once heard that heat pumps first came into practical use in Japan after WWII because of the shortage of oil there at the time.

They didn't become practical in the US until the 1970s after the first oil embargo.

- Jim Katen, Oregon

[fqp25]

Thanks guys.

Interesting fact Katen.

Had a big outside Williamson condensing unit, and the Realtor was set on it was one of the first Heat Pumps. (30-35 year old house) Made me think for a second or two, before I realized it was a just a realtor slash the Maytag repairman....