Hi Velocity cooling experiences please (ME)

Unico/Space-Pak

Sensible cooling and fast cool-down are not the strong-suits of this kind of system. They want to run long and low. (Same tonnage, about half the air as you know). Hence, turn-over takes a while. Not effective for quick pull-down after a weekend away or supportive of setbacks. IOW, your controls should anticipate this and start the cooldown earlier. Not sure if "Smart Response" works in a cooling system as it does for heating.

High delta-T means low dewpoint on the air. Great here in New England where humidity control is key. High desert of eastern Colorado? I always liked blow-through, these are draw-through usually. Not sure if over-drying is of concern in summer.

For ease of balancing, I prefer to "loop" the duct if I can. Ring ducts make for very even pressure all around.

When you go to the outlets especially near the fan but short money if you do it everywhere, use the attenuator kits for the outlet branches. Use the length of the runouts to your advantage for sound attenuation. If they offer as part of the system a fan outlet attenuator, get it or leave room for one later such as a drop-out section with band clamps. Generally they are surprisingly quiet but sometimes you just have to reach for the stars. Long straight shot out of the fan, no hard turns within the recommended diameters. Use wyes instead of bullheads, make it easy on the air. The duct is all 7 inch maybe 9 inch round anyway. Small stuff.

For fittings in a pinch I have used Lindab fittings with the dual gaskets and nice long radii on the elbows, very smooth. But mostly the fittings and duct are proprietary. No matter what though, seal the living s--- out of the ductwork if not a self-sealing system. Brush on mastic. A leak at that velocity can vissle!

Heating is fairly well suited given the air volumes (lower with warm air than for cooling in general). If using a hot water coil can work well using good common sense practices. Not sure how flexible the coil selections are for low-temp condensing boilers though. Heck, you are probably going radiant anyway so why did I bring that up?

Refrigerant- common sense practices of course. Lift and pressure are different given lower SST's on the coil. Charging them can be particular I am told.

Use the usual good things such as auxilliary drain pans, water trip switches, zone for like exposures, stuff you know to do anyway.

Fancier outlets are available in several metals, woods and -egads- platics.

There are dampers available that are inserted in the nozzles with long wires. If your client is an Endoscopist, perhaps he/she can relate!

Overall- great in retro construction because of space concerns or wherever you have constraints. Sheetmetal costs are less of course. Still -given a choice I would use conventional cooling if space was not an issue. The low turnover rate does not allow filtration effectiveness as does a conventional system.

As stated though, for dehumidification it is hard to beat 40 degree supply air. See if that works with you or against you.

My $0.02,

Brad

stick to the rules

Just have to remenber to stick to the basic rules of where to cut in and where not to cut in the take offs on the ducts also if you don't use ther sound asborbing return flex be sure to line the return duct and use a good hi media filter to keep things like the coil clean also try to use the proper amount of registers per ton unico 6 per ton and try to even out your flex runs then you don't have to bother with the restrictor plates .I ve have found that 1 12 ft muffler kit on all the short runs and anything that is using the meatl core flex should have a mimuin of a 6 ft muffler and usually if the take off are cut in right the system will fall into balance .I've found installing the registers near outside wall and for bed rooms run a seperate retrun to each room this way every one can co exist with there doors closed and nobody gets hot and you will have a more even temp room to room less balancing .I've also used the closed loop layout and it worked great air flow and static pressure in the supply duct remained constant system was very quite and work really good . The unico 's are a litle expensive and i probalby do maybe 2 to 3 each year they are a hard sale just lost a 5500 sq footer that had unico all over it HO went which a standard system like his father has at his custum house which by the way doesn't work well if you like it hot it works.Some new custom homes just scream unico because of framing restriction and the fact that there's no attic .Sorry for the rant .Blasting off and outta here for a week time to visit my wife peace and good luck clammy

Peerless Pavillion

I did a heavy renovation to a 100yo farmhouse last year. Used a Peerless Pavilion system. We used 8" snaplock pipe as the trunk duct taped and wrapped with R8 ductwrap. (Good insulation is part of this story!)

It is an 1800sf two story and it was done as one zone with 10 outlets per ton. (3 ton system) Hydronic heat from Noritz LP tankless water heater and a 10 seer A/C outdoor unit. Tankless does domestic and heat.

The system was put online June 1 2005 on a 100* day. It ran for a day bringing the house down but we had a condensate leak and had to shut down and dry out to fix.

The next day brought the house down again form upper 90*s indoors and ran it at 73* for the month since we were showing the house to sell.

Electric bill for June came in at $65! WOW! We were floored!

Also, the temperature inside the house is dead even between the upstairs and downstairs. I used a 10/ton outlet ratio thinking I could balance it if I needed, but I didn't have to. The system is constant on with the fan set at about 50% for the standby mode. This keeps the air from stratifying. Works great!

It was installed per the instructions and is also surprisingly quiet.

The new owners like the system and have bought 320 gallons of Propane since they moved in in August of 2005! For heat and DHW. That’s not half bad.

As far as forced air goes, I don't think you can beat the comfort and even heating and cooling of a space. A bit pricey up front but you get what you pay for.

Peerlesss has a little beter joining fitting for branch takoffs, and the flex duct is the silencer, so you don't have to worry about doing something wrong and the AHU does not de-rate the outdoor unit. It's a very forgiving system system to install.

hi v

i would like to hear if anyone had complaints about outlet placement. You are not supposed to place the outlet where the occupant could complain about the draft or over a window where it would make the curtains blow around. In an existing house you can see how the furniture is set up and locate the outlets so you're not blowing on a chair. In new construction I can't see how you can do that.
What is the seer rating you get when you use a 13 seer condensing unit? 11.5?

Brent

I did a Unico

we started with the fiberglass duct and then decided we didn't like it. We were concerned it would blow tiny bits of fiberglass throughout the house. You could scratch it gently with your fingernail and bright sunshine would show stuff would flying everywhere. SO we used metal with fiberglass socks on it. LOTS more work if you go that way.
I was around a Space-Pak this summer which used plastic main duct. It looked very good to me, and possibly the takeoffs might be a bit more user friendly. I bought a 3 1/2" or so carbide hole saw to do the holes in the lathe and plaster ceiling in the old house. It works well.Kevin

Mark check this system ( heatlink.ca )

the web site needs to be updated as AirLink isn't in the main menu but is in the PDF files as airlink L3110. The system is called AirLink and is made by Heatlink of Cananda. heatlink.ca