hyrdo air system conventional or high velocity

Mike9

What do you feel is a better way of doing a hydro air system? Should I use high velocity or conventional duct work?

David_5

choices

If you have room for conventional ductwork and someone to do it, I'd go that route. Hi velocity requires less skill to install but is more expensive for the equipment. I have both in my house and am comfortable.

David

Ted_9

I think its about logisticly which on will install better. I also have installed both and the Hi velocity type should provide a higher comfort level. I've had people make the decision to go high velocity just because its low profile(the grills).

dconnors

Go Hi-Velocity

Hi Velocity is the better way to go. Less chance for temperature variation in the rooms. Use a smart boiler control like the Buderus Logamatic.

Brad White_2

Advantage of High Velocity is

that you use the same tonnage (cooling capacity) but only about half the air. Therefore the air is cooled way below the dewpoint, to the 38F to 42F range as opposed to the 53-55F range of conventional AC systems.

Result? Excellent dehumidification. Removes gobs of moisture, about 50% more than conventional AC.

Drawback? Takes a while to cool the house down after a time away or when reset for a day or so. Best technique is a programmable thermostat set to start in advance of your return by 3-4 hours versus an hour or so normally.

John Mills_3

Price, efficiency & capacity

High velocity stuff can be pricey though labor savings helps cut that back.

It also reduces SEER, especially Unico though they say the Space Pak folks may be fudging a bit. The typical 12 SEER outdoor unit loses about 1/2 a ton and 2 SEER points and will be ARI rated around 10 SEER. For the same or less money than a HV air handler, you can get a top of the line variable speed air handler and couple it with a humidity controller and really suck out the moisture just like with a HV system. The VS air handler bumps the 12 SEER up to 13+ SEER so operating costs come down from what the HV does.

Brad White_2

True-

The high velocity system pressure cancels out the lower air volumes so the evaporator fan HP is about the same, sometimes higher. Also as you pointed out, the SEER is skewed with that narrower approach between refrigerant and leaving air temperature. I agree, use low-V where you can and save Hi-V for tighter fit or where extreme dehumidification is more of a concern.

Even Low-V with dehumidification controls (better than normal temperature-responsive) cannot remove as much moisture as Hi-V and that is what it is mostly about.

Of course, if you have Hydro-Air Low-V, with coils in the reheat position, you can circulate hot water at reduced temperatures for reheat, but your local energy police frown on that... :^)>

DaveGateway

But in heat mode

I was under the impression that you would feel the "on/off" of the hot air movement. I thought that hydro-air offered cooler water temps to allow for longer slower conventional blower cycles on a standard duct system. This would help even out the temps around the rooms. The "less air" of a HV system meens more BTU's would have to be pumped in to cover the heat loss, so higher temps at the vents. HV systems are less efficent since you loose 2 points off the SEER ratings of the condenser. HV's only value is as a solution for retro jobs where fitting conventional ductwork cannot be done.

Mike T., Swampeast MO

One thing that nobody mentioned is that Hi-Velocity systems are designed around air cooling, not air heating. Only after you have sized it for cooling can you determine your heating ability.

I haven't checked since Unico introduced the water coils, but before that they said that in general your heating needs will outstrip cooling north of the Mason-Dixon line and you'll need some other form of heating in addition to the high-velocity.

If you start making radical changes to the A/C design (likely adding outlets for more heating), you'll lower velocity and reduce the aspiration that makes them work nicely to begin with...

john wood_3

Not Energy Saving Products!

ESP's Hi-V air handlers were primarily built for heating in Canada. You have to add an A/C coil for cooling.

Mike T., Swampeast MO

Hi-V A/C Systems Seem Similar to Radiant

They promise greater comfort at a higher than normal air temperature, similar to the way radiant promise greater comfort at lower than normal air temp.

I've felt enough of both to know that they do as they say as long as you use the thermostat properly.

Mike T., Swampeast MO

Hi-V A/C Systems Seem Similar to Radiant

They promise greater comfort at a higher than normal air temperature, similar to the way radiant promise greater comfort at lower than normal air temp.

I've felt enough of both to know that they do as they say as long as you use the thermostat properly.