High Velocity Air Systems

Discussion in 'General Discussions' started by thackery, Jan 16, 2009.

  1. thackery

    thackery New Member

    Maintenance Manuals

    I have a "user" manual for my Waterfurnace, however, it covers very little of the questions asked on the forum.
    Does anyone have "maintenance" manuals, "technical" manuals, etc.
    Most manuals are available in pdf format so they are easily used and stored electronically using Adobe.
    If this forum could start storing these manuals as us the users of the forum provided them, a very useful library of information could be created.

    I work in a technical equipment type of job, we have created these pdf libraries with any and all information we can lay our hands on about our equipment. It is amazing what we extract from this shared library.

    Just a suggestion.

    Otherwise, if anyone has any manuals other than the user manual for an Envision Waterfurnace, I would love to have a copy. Or maybe someone could point me in a direction to get them online.

    Good luck on the current heating season.

  2. wrice3

    wrice3 New Member

    Try this site

    Most of what you want/need is here:
    Engineer Page

  3. hicar1

    hicar1 Member

    Can someone explain to me about the benefits of using a high velocity air system. Also the basics of how the systems works and when are time that you should consider one. How can they be used with a GEO HP? Are they used in addtion to the air handler in the system, a system of thier own, etc. Are they more costly?
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    High velocity is more costly, less efficient, and requires a carefully thought out installation to avoid uncomfortable drafts.

    It has a huge advantage in that its ductwork can be much smaller, so it fits better in difficult retrofits, specifically buildings without pre-existing ductwork

    I wouldn't consider it in new construction
  5. hicar1

    hicar1 Member

    Thanks for the info.
  6. teetech

    teetech Member Forum Leader

    When using high velocity with GEO I would recommend a water to water unit and run a hydronic coil. A hydronic set up is much more forgiving with high static/lower CFM air delivery than DX.
  7. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    Shame on you. I can tell by your post you are clueless on H/V duct work.

    I like Unico as they use long plenums and short expensive small ducts. I have used space pac, but not the perless product.

    To do duct design one needs to know air flow.

    Teetech you are spot on on water to water.

    We installed in six days with a four person crew two zoned five ton systems, mastic, insulation, distribution attenuators and zone dampers and air tubing for a 6400 square foot home. Two of the four people had never picked up a pair of tin snips. The home would have needed at least two systems at standard velocity and with 4 Union tin bangers and a full house build shop would have taken 21 days at 8 hours per day. Sooo it may cost more but is faster and easier to install.

    It must be designed however.

    It is very efficiant. It is better than at humidity removal in cooling.

    I was too busy to take pictures ao all you alls will have to wait to see it until next week.
  8. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I'll admit to no first hand experience with Unico and frequent cluelessness. However:

    It stands to reason, though, that blowing air at several inches WC vs. a fraction of an inch WC is going to require significantly higher blower power per CFM. When last I browsed Unico product offerings, the efficiencies available were no great shakes.

    Ensuring that the streams of air from high velocity duct outlets don't strike and annoy occupants takes a level of design care not so required of conventional systems. The Unico ad that sticks in my mind pictured tiny floor ducts configured to wash floor-to-ceiling windows. That works well in that situation, but not every home offers such an arrangement.

    HV ducts have their place in certain retrofit situations. If we ever decide to cool the home I grew up in near Boston, it'll almost certainly be the only viable option. The home has plaster, low ceilings and many small rooms. I may yet become a student of applied HV.

    Proper airflow to each room is of course crucial to proper duct and system design. Its direction, velocity, noise and throw figure in as well, and HV duct systems complicate those considerations.

    I think it telling that HV is not typically the first choice system in new construction, owing to its inherent compromises.

    I agree that W-W / hydronic could help with HV design issues, and am looking forward to the pics you promise.
  9. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    This is a WIP

    As promised here are some photos. I had intended to take an amp reading on the blower motor to disprove the higher cost issue. Trying to get every thing done for the pre-drywall inspection. I'll get back to the basement while the drywall guys do their thing.

    Attached Files:

  10. zach

    zach Member Forum Leader


    Very interesting. The coil is contained on the right side of the unit in the bottom picture? With the fan on the left?

  11. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader


    Yes. The system is pull-through. I will get you more info in a few hours. I got your plans, pics and manual J. Just out of the shower after three weeks or so on the road. We sure could have used your head and hands.

    The things I like about the H/V stuff is the reduction in labor and the ability to teach skilled hands to do the work if the design is right. I posted above about speed of installation.

    Here are a few more of this job.

    Attached Files:

  12. hicar1

    hicar1 Member

    you got pics of the unit supplying the hot water to the coil? where is it located in the house?
  13. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    In the basement where it belongs

    Here is the boiler. Heat pumps in the spring.
  14. hicar1

    hicar1 Member

    so you're running floor, high velocity, and indirect HW with this boiler?
  15. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Yes, Yes, No

    This is a water to water geo system. The boiler will be the back up heat. The DHW is by gas fired tankless units.

    Basement floor is geo radiant. First floor is geo radiant. Second floor is geo hydro/air.

    All cooling is geo/hydro air.
  16. teetech

    teetech Member Forum Leader

    That's quite a set up Mr. Curtis and obviously a large house. I'm curious as to why your not using a mod-con boiler. I am assuming DHW is tankless because of multi point needs and little room for the tanks.
    What prompted GEO hydro heat for second floor?
  17. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    The choices are all customer/builder driven

    Thank you Teetech, coming from you that is a very large compliment.

    When the economy started to tank a supply house locally had a new Crown CI boiler they wanted to get off of at below their cost, so we bought the unit and put in storage. We drug it into the basement once the roof was on. We are using it for construction heat with the fuel being supplied by the rural gas co-op.

    We have room for tanks, but I had installed a tankless for the owner's brother. The brother's step son is working for a wholesale house out of state and gave us a good price and my customer kept the business in the family.

    Since we have a water to water radiant geo set up in the barn/shop on the property we knew we would use water to water in the home. When we started to look at the heat delivery of chilled water equipment we where impressed with the low tempurature BTUH numbers and decided to skip the staple up radiant for the up stairs bedrooms, however we are adding staple up in the bonus room over the attached garage.

    The plan is to keep the geos running as much as possible with the help of a Tekmar whole house control system using their tekNet4 controls. We have sub divided all the systems as much as possible to allow maximum use of the water to water units. Yes there will be two 5 ton units plumbed to a 10 ton loop field in the pond. The units will be staged and given equal exersize. Either or both units will have access to the loop field as needed.

    If the geos can not keep up with the demand for the air handlers we will switch them to the hot loop off the boiler. The hot loop can also be injected into the cool loop if needed, or as an emergency heat overide should both heat pumps go down.

    We have impossed an Arzel Zoning system to the two air handlers. In the event that the big party is happening on the hotest day of the year the upstairs system will shut down the bedrooms and bonus room and dump all 5 tons of cooling into the great room for the party.

    The owner/builder and I have been working on this system for almost 4 years. It is a wip as I mentioned and the design has morphed as we worked. We left the ability to add a wood boiler and solar panels in the future if needed. With the Tekmar control system I will be able to run the house from my office or the owner can run it from his Blackberry.

    It has been a great project so far.

    Thanks for the look.

    Here is a shot of the basement before the pour.

    Attached Files:

  18. teetech

    teetech Member Forum Leader

    I've heard the teknet4 is a nice control and with remote access it draws attention from the techies.

    I like your "think outside the box" approach to things and it looks like you have all the bases covered.

    Keep us updated as I would like to see more.
  19. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    It sucks that we do not have an ISP on site

    I have to go down the road to the local supply house to pick up my email or look something up.

    We passed our insulation HVAC rough-in with flying colors. I did need to add a few fire stops, but I always try and let the inspector have something to add to a job. We are home for a few days then down to Massillon, OH., to continue the spring/geo system. We have an ISP on that site.

    Nothing much new except dotting the I,s and crossing the T's. I am planning to use HDPE in the pond this time with a reverse return. I have a new digger who calls himself "oil field trash" and he is certified up to 12" on fusion welds for gas lines. I am sure we will not have any leaks. I will use the slinky pattern we installed for Zach up in New York. We will use recycled side walk and maybe chain link fence to get the loops to the bottom of the ponds so they silt into the bottom.

    I did not take the time to amp the advanced controller PSC blower drive to get Engineer some numbers. I look forward to feeding him and Gabby numbers from the spring job in Massillon.

    I am attaching a shot of the HV duct system from the floor. It will give you a better idea on how it will work with the tekmar control system, and the Arzel zoning. I have a better shot of the hot loop/cool loop piping with out my table is in the way.
  20. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Looks well installed.

    I have lingering concerns about increased blower power and managing throws and air velocities for comfort in rooms served by high velocity systems.

    If the air is just for cooling then maybe the air issues are less important

    If we ever do a deep retrofit of my Mom's place in Mass to lose the 1000+ gallons of annual oil use and provide AC, I'll need to nail this stuff down.

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