Residential High Velocity A/C systems
Residential High Velocity A/C systems
(OP)
Looking for opinions on the residential style high velocity AC systems. Typically 2000 FPM fed through 2" and 3" flexible ducts.
Are these systems noisy compared to either the mini split VRV systems or typical low velocity hard ducted systems?
Due to high velocity, is static pressure so high as to make the fan energy significantly more than low velocity residential systems?
Are these systems noisy compared to either the mini split VRV systems or typical low velocity hard ducted systems?
Due to high velocity, is static pressure so high as to make the fan energy significantly more than low velocity residential systems?





RE: Residential High Velocity A/C systems
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RE: Residential High Velocity A/C systems
Fan energy- yes- that can be a high percentage of system energy use.
These systems rely on jet-mixing high velocity, but very cold (and dehumidified) air, with room air to create mixed conditions. In some climates where indoor humidity may be high, the air terminals (small plastic jet nozzles) may get condensation on them from the entrainment of room air in the jet/mixing stream.
RE: Residential High Velocity A/C systems
Higher equipment cost - due to increased statics preventing the majority of residential/light commercial equipment manufactures from meeting the spec.
Higher energy cost - from larger H.P. airhandlers to meet S.P. requirements.
On the plus side I would think it would be a less installation cost.
But like I said, I have no priors with this system.
Very interested in opinions.
Andy W.
RE: Residential High Velocity A/C systems
RE: Residential High Velocity A/C systems
Architectural, Yes. Old big house to be used for offices for college. I'm most concerned about lack of zoning. But that will be brought up soon with the client. I wanted to find out about the rest of the potential issues.
Thanks all for your input so far.
RE: Residential High Velocity A/C systems
Not many people make them anymore.
The fan pressure required is high and they can be noisy if improperly designed/installed.
RE: Residential High Velocity A/C systems
The system is noticeable when it is on, but it is not a mechanical noise, it is a "white" noise. In a new system install, I'd be a little hesistant to use it but I've heard furnace systems just as loud. The only difference is lower hp and static with a furnace - not necessarily noise.
The lower humidity levels in our house due to this system is noticeable and this atmosphere is more comfortable in my opinion.
I've always wondered about their possible application in a new home with in-floor radiant heat. That seems like a good match - clean floor lines.
Oh - one other thing about these systems - the jet diffusers are not obtrusive. You don't even notice them. They usually have a paintable variety and if you use them, you can make them essentially disappear.
RE: Residential High Velocity A/C systems
As far as noise, research the manufacturer. Those who require special vent reductions or special sizing for long runs will give you more noise.
RE: Residential High Velocity A/C systems
The lower humidty due to the colder air sounds as if it has a comfort advantage in humid climates. I don't see the energy efficiency benefits that GuyH mentions. The fan energy may be a wash since it has a smaller volume but at a higher pressure than standard systems. I would expect the compressor energy to be higher however since the suction pressure (or temperature) should be lower than a standard system and it will have a higher latent heat load with approximately the same net Btu/hr.
RE: Residential High Velocity A/C systems
Duct systems are smaller and will fit inside 2X4 walls and such, so retrofitting old homes is a big market for them.
Blah Blah Blah... you probably already know all this.