Energy Saving Product's Hi-Velocity System

[numbawunfela]

I'm looking to start installing this:
http://www.hi-velocity.com/en/index.html

HE and HV units specifically-

Any thoughts or experiences with this piece of equipment?

It is similar to Space Pak and Unico, but there are a few differences that seem to set it apart.

It has a variable speed motor which slowly ramps up and varies speed according to load - sounds good for zoning.

It uses a 'rough in boot', which allows for an easy 90 degree connection in a wall or ceiling.

It has a HE duct size (2.75") which directly replaces 2 normal 2" sizes, cutting on labor and materials.

This is what I glean from reading the materials online - anybody actually installing this have any input?

Any favorites for condenser matches that have worked well for you?

thanks!!

[tomgeer]

not much different from the unico system.

They run colder.

important they're installed correctly.

Make sure the installer is certified in the high velocity duct system industry.

[cmajerus]

installed around 12 of them, follow the install instructions to a T make sure you adjust the line temp to EXACTLY the temp it calls for in the book and it will work great.

[numbawunfela]

thanks guys.

As an installer, how does that 'rough in boot' fit for the large HE duct sizes? a standard 2 X 4 wall is not too shallow for those to fit?

The manufacturer is really vague as far as seer ratings for the air handler as far as I can tell. since the seer ratings need to match between ahu and condenser - cmajerus, have you used any particular condenser with good results?

[cmajerus]

thanks guys.

As an installer, how does that 'rough in boot' fit for the large HE duct sizes? a standard 2 X 4 wall is not too shallow for those to fit?

The manufacturer is really vague as far as seer ratings for the air handler as far as I can tell. since the seer ratings need to match between ahu and condenser - cmajerus, have you used any particular condenser with good results?

we always used the ttb trane condensers on the ones we did, we heard conflicting stories on seer ratings with HI V's the mfg says they stay the same as with standard indoor units, others have told us they cut the seer rating down considerably, haven't installed one since the 13 seer mandate so not sure what we would use now.

[heatkits]

We have installed them in every possible application you can imagine. I have three of them running in my house now and two more in my apartments next door.

Have I had any problems with them??? Why of course, almost every one of them has had some sort of problem. But then, what doesn’t have problems? It's not a product you can install and just walk away from, they are constant mantainance at first, but once the bugs are worked out they run fine with minimal routine mantainance. My partner wants me to stop using them, as he sees them as a major lost to the company profitability and I have to reluctantly agree with him.

For the most part we have returned to installing conventional low velocity systems as our mainstay but still do Hi-V for certain applications. The Hi-V systems cost almost 2K more than the Lo-V system.

[numbawunfela]

Have I had any problems with them??? Why of course, almost every one of them has had some sort of problems. But then, what doesn’t have problems? It's not a product you can install and just walk away from, they are constant mantainance at first, but once the bugs are worked out they run fine with minimal routine mantainance.

I have installed a unico system, do you mean the ESP Hi-Velocity system is more troublesome than the others (like Sacepak)? or they are all, as a catagory, a little buggy?

Any comments on the HE large duct or the rough in boots, or the EPC variable speed motors?

Thanks again for the feedback.

[heatkits]

I can't comment on other brands as we were exclusively Hi-V systems. ESP changed their load calculation software design which led us to be under sizing several units (about 10 of them) before we caught onto the problem. This little mistake ended up costing us eighty grand to fix. ESP helped us for a while, but later turned their back on us and left us to resolve the rest of the problems. We haven't installed anymore of their system since then.

Another costly problem that we encountered was the stratification that was taken place in the poplar, older, multi story homes in our area. A single system can't overcome this effect and leads to overheating in the summer and under heating in the winter for the second and third floor areas. ESP was adamant their systems would homogenize all the air and the whole house would be within 1 degree (+ or - 1). It doesn't work and we had to install additional equipment at a huge cost to us and our customers.

Next problem is balancing out the refrigerant charge... No easy task, to say the least, sometimes it would take several tries over several days to get it regulated.

ESP had flex duct failures issues as well. The end termination was just a 2" vac. pipe coupling taped in place that would fall apart. When our customers would complain that some or all the vents weren’t working we would find them completely detached. Not a big problem if found them early on or they were where we could get to them, but a major problem if they were in walls or inaccessible areas. ESP helped us at first, but soon grew tired of the problem and though the blame back onto BioFlex and washed their hands of it. BioFlex is a Canadian Co. who sold the product indirectly and couldn't understand English... So you know who ended up paying...

Last, but not least, Condensing units: Any unit that had a Bristol compressor in it was in for a short life, real short.

ESP tells me that I'm the only one that has ever had problems with their products... I guess they're right, but it sure seems funny that two of our local supply house chains have switched to Unico. It must be they are getting a better deal on them.

[cmajerus]

I can't comment on other brands as we were exclusively Hi-V systems. ESP changed their load calculation software design which led us to be under sizing several units (about 10 of them) before we caught onto the problem. This little mistake ended up costing us eighty grand to fix. ESP helped us for a while, but later turned their back on us and left us to resolve the rest of the problems. We haven't installed anymore of their system since then.

Another costly problem that we encountered was the stratification that was taken place in the poplar, older, multi story homes in our area. A single system can't overcome this effect and leads to overheating in the summer and under heating in the winter for the second and third floor areas. ESP was adamant their systems would homogenize all the air and the whole house would be within 1 degree (+ or - 1). It doesn't work and we had to install additional equipment at a huge cost to us and our customers.

Next problem is balancing out the refrigerant charge... No easy task, to say the least, sometimes it would take several tries over several days to get it regulated.

ESP had flex duct failures issues as well. The end termination was just a 2" vac. pipe coupling taped in place that would fall apart. When our customers would complain that some or all the vents weren’t working we would find them completely detached. Not a big problem if found them early on or they were where we could get to them, but a major problem if they were in walls or inaccessible areas. ESP helped us at first, but soon grew tired of the problem and though the blame back onto BioFlex and washed their hands of it. BioFlex is a Canadian Co. who sold the product indirectly and couldn't understand English... So you know who ended up paying...

Last, but not least, Condensing units: Any unit that had a Bristol compressor in it was in for a short life, real short.

ESP tells me that I'm the only one that has ever had problems with their products... I guess they're right, but it sure seems funny that two of our local supply house chains have switched to Unico. It must be they are getting a better deal on them.

your not the only one, and my guess there are more than just 2 companies out there. We only had 2 major problem child jobs, but neither are perfect to this day, just tolerable. One question I would have is are there any other indoor units that would be compatible to the duct system installed for the HI-V? ie: round metal duct, not fiber pipe.

[numbawunfela]

ESP changed their load calculation software design which led us to be under sizing several units (about 10 of them) before we caught onto the problem.

Another costly problem that we encountered was the stratification that was taken place in the popular, older, multi story homes in our area. A single system can't overcome this effect and leads to overheating in the summer and under heating in the winter for the second and third floor areas.

Next problem is balancing out the refrigerant charge... No easy task, to say the least, sometimes it would take several tries over several days to get it regulated.

ESP had flex duct failures issues as well.

Last, but not least, Condensing units: Any unit that had a Bristol compressor in it was in for a short life, real short.

Of these problems it seems that stratification can be overcome with zoning or something similar. stinks they insisted that they could overcome the problem some other way. looks good on paper...we all know how that goes.

as for the rest, it seems as though they may have been overcome with fine tuning to the equipment. Was that your experience? how many of these issues are currently issues still, and how many were issues for you till the end (besides the improper sizing of the equipment, which CAUSED the end)

It seems that with 300 units installed, you found at least some of the issues were addressed, or that the issues were infrequent, but beastly when they were present.

It seems that a multi-stage condenser is a must for any system with a variable speed blower to allow for the lower loads. that may be the source of the compressor failures. correct me if I'm wrong.

I have been involved with the manufacturing side a little, so I may come across as slightly more... tolerant than some.

Thanks again for the input, good to go into a new product line with your eyes open.

[tomgeer]

we always used the ttb trane condensers on the ones we did, we heard conflicting stories on seer ratings with HI V's the mfg says they stay the same as with standard indoor units, others have told us they cut the seer rating down considerably, haven't installed one since the 13 seer mandate so not sure what we would use now.

What i learned was the system at best would get up to 12 seer, this is why unico fought to start up their own industry, " HVDS ".

We use the lennox 15 seer in areas where noise is a problem. Other than that we use the 13's.

Based on my eer calcs they ( run about 12 - 13 on a 80 deg day.

[numbawunfela]

What i learned was the system at best would get up to 12 seer, this is why unico fought to start up their own industry, " HVDS ".

I read the applications unico, spacepak, and EPS submitted for exemption from the 13 seer mandate. the issue was mainly the blower fan having to generate a higher static due to the duct design. this put them over the top for overall power consumption, thus the 10-12 seer ratings. strictly speaking, it seems this would not affect the evaporation characteristics that is at the heart of the requirement to match 13 seer condensers to 13 seer evaps.

of course one could also argue that, if left unregulated, there is no reason for them to upgrade a thing, meaning regardless of what the fan is doing the unit remains a 10-12 seer evap coil, making the issue of matching to an appropriate condenser moot.

Nice word huh? moot.

[numbawunfela]

I can't comment on other brands as we were exclusively Hi-V systems.

Next problem is balancing out the refrigerant charge... No easy task, to say the least, sometimes it would take several tries over several days to get it regulated.

Last, but not least, Condensing units: Any unit that had a Bristol compressor in it was in for a short life, real short.

Hey there Mr. Kits, I'm engaged in a little engineering personal project, a little bit in the way of details will be helpful if you have a moment.

With regard to refrigerant charges, did you have issues with icing if the charge was not exactly right? High/Low pressure faults?

I'm in contact with ESP but was looking for input from the other end as well.

See if this interests you from your experience:
http://www.rawal.com/intro_pages/intro_what.html

THis mod allows you to set the evap temperature, and actually de-rate the evap to match the load. this eliminates icing, and provides thermostatic control of your evap's temp. then your TXV rides it's 10 degree superheat on top of whatever evap temp the Rawal is set to. this means the rawal garantees the 40 degrees ESP wants, and the TXV garantees the 10 degree superheat. At least in theory anyway, I'm conferring with the manufacturers to make sure I'm reading their literature correctly.

Also it allows your Condenser power consumption to modulate continuously as if it was a multistage, boosting your seer rating, while seemingly compensating for the one most serious problem from an installer's viewpoint which is getting the charge right.

There is a lot more info on that Rawal control that you can only get if you e-mail and ask for it.

Something else I noticed as I play with thermodynamics online (FUN!!)
The ARI website publishes data for compatible units, and their actual output. Plugging in models for the Hi-Velocity system and the nearest Unico equivalent matched to the same condenser we get the following results:

ARI reference number 1191727-Unico system 11.15 Seer and 29600 Btu/hr

ARI reference number 1352382-Hi-V system 17.90 Seer and 34800 Btu/hr

Just go to this URL:

http://www.ahridirectory.org/ahriDir...ultSearch.aspx

and plug in the ARI reference numbers in the first field. That is all you need to bring up the rest of the info. I suggest you do it in two separate windows so you can compare the two results.


I'm toying with the idea of zoning one of these units in the plenum. Arzel has a very helpfull guide to this here:
http://www.zonocity.com/index3.html

The crux of the issue here is airflow over the evap, the minimum being affected by the ability of the condenser to mudulate it's oputput (stage) to match varying loads. you'll see a formula in there of 3.5 taps per ton per zone minimum for single stage condenser, 2.5 per tonm per zone for multistage. that is - for a 3 ton system

2.5 x 3 = 7.5 or 8 taps per zone minimum w a multi stage condenser
3.5 x 3 = 10.5 or 11 taps per zone minimum single stage condensers

Good info. Please let me know about icing HeatKits. thanks for your input!!

Numba

[beenthere]

your not the only one, and my guess there are more than just 2 companies out there. We only had 2 major problem child jobs, but neither are perfect to this day, just tolerable. One question I would have is are there any other indoor units that would be compatible to the duct system installed for the HI-V? ie: round metal duct, not fiber pipe.

You can use round metal for HV.

[heatkits]

It's always the other way around, getting the evap temp to 38 is the problem. Balancing the charge when there is too much load, not enough loads, too humid, too cold out doors or any other associated problems and you can be here for hours.

All my problems have been under sizing and not taking stratification into account, I actually believed the story about how fan forced air movement would eliminate it... Wrong (well, maybe in Canada it dose).

We won’t go into the flex ducts failing, after all that wasn’t their fault, they didn’t make them… Or the fact the fan motors fail due to running on low voltage (rheostat controlled). Change is good… Now that these problems have been corrected and the devalued dollar they have essentially priced themselves out of the market. I have to charge 2K more for the Hi-V over a conventional system.

[beenthere]

Keep pricing references out of the public forums.

[numbawunfela]

It's always the other way around, getting the evap temp to 38 is the problem. Balancing the charge when there is too much load, not enough loads, too humid, too cold out doors or any other associated problems and you can be here for hours.

So the system either is at a 45-50 degree suction line (under-charge), or it is tripping on high head (over-charge). getting the magical 38-42 with out popping safeties is the issue. Is that right?

[numbawunfela]

You can use round metal for HV.

I actually heard of some guys using central vacuum cleaner supply pipe for longer 2" duct runs. the inside is VERY slick to keep dust from accumulating, and it is 1/4 the cost per foot (I'll edit that out if I need to ) and eliminates the need to compensate for low flows on longer runs, just make sure you end the run with 10' of the regular hose for sound attenuation.

[beenthere]

A 2" supply, carrying 40 CFM, is about 1800 FPM. Ain't gonna be much dust collecting in a pipe.
At 30 CFM its around 1375 FPM.

[numbawunfela]

A 2" supply, carrying 40 CFM, is about 1800 FPM. Ain't gonna be much dust collecting in a pipe.
At 30 CFM its around 1375 FPM.

I agree, HVAC guys don't care about dust, we have filters for that, and the velocity is high as you say. i was illustrating that the pipe is designed for central vac systems, where dust is a concern. and as such it offers very low friction losses, when compared to the flex that would otherwise be used.

Also the fittings on the Vac pipe is as Heatkits pointed out, compatible with the Hi-V duct fittings, since ESP uses the same fittings on their flex.