Is there a problem using a split tranquility 27 system with a high velocity air handler?  I've been told on a project that this combination won't work in the heating mode.

Have not done it myself, but have heard positive feedback on such systems. Is the HV system already in place?
j

Just be sure that guidelines are followed for the HV system. You should require at least 8 supply outlets per ton. Also, expect the efficiency to take about an 18%-22% hit. Capacity will also take the same amount of hit. This means that if you had a normal duct system and required 4 tons, then a high velocity system will likely require 5 tons. I'm not posting this as an expert on this subject, but these are some things I've learned lately from a dealer with experience trying to fix problems...

I'll bet placement of outlets is more critical in HV owing to possibility of uncomfortable drafts

Placement is a huge part of it, too. The two biggest complaints I've heard of are:
1. NOISE
2. NOISE

We distribute Hi-V and have a install manual posted on line, It provides guide lines for out let numbers related to the different models. Some of the key points are that there are minimum and maximum outlets for each size unit (50,000, 75,000 & 100,000 BTU. For cooling you want maximum out lets, heat can be minimum recommended outlets. To avoid noise/sound use maximum. It is a fairly easy install and used with a chiller or Geo system you can have multiple air handlers off one tank. further you do not have the conventional limitations of compressor line sets.
I have never heard of reducing out put the Hi-V by 20% for cooling. Maximum outlets is the key. Outlets can be on the floor, wall or cealing. The area of air turbidity is about 18 diameter by 4 feet. Avoid placing outlets over/under curtains and places where there will be chairs/couches.
There is some advantages with Hi-v, they offer a great filter, outside air is easy or you can place an air to air recovery in line on the return.
Good luck,
Dan

Thanks for your ideas, I will count the outlets. Dont think it is near 8 per ton. I get the feeling also there may be something about this split system in particular that manufacturer may be having heating problems with?

The heat pump has no knowledge of what happens downstream of it. So if the flow rate is correct, you can use any pressure you want (until the noise bothers you).

This may help,
here is a link to the plenum sizing and outlet requirements of the HI- V 50, 70, 100, 140
http://www.blueridgecompany.com/image/view/64
Dan

Dan,
Are you discussing HV with hydronic or DX coils? The unit mentioned above would use a DX coil.
J

Joe,
HI-V is designed for a few coil types, here is a couple links for alternate coils, there outlet and plenum size is a constant. There is also a good copy of the install manual on our site, it is help full in understanding the system ducting and options.
have a good week,
Dan

http://www.blueridgecompany.com/radiant/hydronic/271/esp-water-coil-modules
http://www.blueridgecompany.com/radiant/hydronic/116/esp-cooling-and-coil-modules

I get that it can work either way, but you seem to be discussing hydronic application. The Tranquility 27 mentioned by the author of this thread would require a DX coil in the air handler.
j

J,
The RPM-E TX is the same as the DX , I clarified that just now with the rep, You need to chose between R- 22 or R-410 A,This is done at time of purchase.
Dan

K dan,
appreciate your enthusiasm for your product, but you spoke of chillers and storage tanks...sounds like hydronic coils.
J

J
The HI-V offer coils for multiple applications, Water or compressor systems, here try this link; http://www.blueridgecompany.com/hydronic/forced-air/energy-saving-products/5
This will give you the line up of most of there product in category. They even offer a very good quality air filter system, it is a private label Sun Pure unit with custom flange to adapt directly to there box.
Dan