High velocity forced air heating system

[SNations]

I just saw my first ever high velocity forced air heating system. Does anybody know any significant problems or downsides to this type of system that I should warn my clients about?

[kurt]

How was it set up?

[Jim Katen]

I just saw my first ever high velocity forced air heating system. Does anybody know any significant problems or downsides to this type of system that I should warn my clients about?

Space Pak or Unico?

Was it a hydro-air system, where a water heater sent hot water to a heating coil?

They're efficient and reliable systems, but for heating, I'm not a fan. They use very cool air to heat with and the air speed at the outlets is very high. That makes placement of the outlets absolutely critical. If a person is within the "cone of influence" of one of these outlets, he'll feel very uncomfortable.

These systems are best used for cooling of historic buildings that have hot water or steam heat. I see little advantage to using them in new construction or for heating.

[SNations]

Space Pak or Unico?

Was it a hydro-air system, where a water heater sent hot water to a heating coil?

They're efficient and reliable systems, but for heating, I'm not a fan. They use very cool air to heat with and the air speed at the outlets is very high. That makes placement of the outlets absolutely critical. If a person is within the "cone of influence" of one of these outlets, he'll feel very uncomfortable.

These systems are best used for cooling of historic buildings that have hot water or steam heat. I see little advantage to using them in new construction or for heating.

Unico. Hot water delivered from the boiler.

Very old house, with a second floor addition put on a few years ago. They left the boiler, and the radiators on the first floor, and put in this high velocity heating/cooling system on the first and second floors. So heating on the first floor is now both radiators and high velocity air, and the two heating systems can't be controlled independently.

I told them that high velocity air works well for cooling, because moving air tends to cool you so everything is working towards a common goal. With high velocity heat that's not the case.

There were also barometric dampers on the gas-fired boiler and water heater. I'd never actually seen such a damper because I've never seen an oil-fired heating system. But I looked it up and these dampers are designed for gas appliances, although I don't know why someone thought it necessary or desirable. So there were some interesting design decisions made several years ago.

Thanks for your input Jim. (p.s. This is what I mean by home performance. This is what intrigues me.)