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  1. PacificSteve

    Mortarless Rock Retaining Wall

    I would have to agree that intense analysis for a 5 foot wall is probably more of an academic exercise than a real pratical necessity. Hyrdostatic pressure will be nil, but I would personally backfill the near side with gravel or other readily available small loose stone, especially if your...
  2. PacificSteve

    Can we use VFD's with both primary & secondary loops?

    Imok, certainly you have learned answer to the question, and the Hartman site is great. But first, what exactly is the "problem" with low Delta T. Of course, there is efficiency loss, i.e. it is easier to cool down something warm than something not so warm. But if 2 way valves...
  3. PacificSteve

    Can we use VFD's with both primary & secondary loops?

    I cant think of any reason that the secondary would have higher flow requirement than the primary. I think this is a basic premise that can be dispensed with, and the problem goes away. I have never heard of variable primary variable secondary. Defintely do not go with VP if you have VS...
  4. PacificSteve

    Artic Master RMS-

    I worked with a guy who got 30% fuel savings when applying a boiler controller (basically increased the historisis aka deadband). The reason he really achieved 30% savings is that he simultaneously fixed other system problems which were ignored or not understood by the maintenance staff. A...
  5. PacificSteve

    Optimum Condenser Water Temperatures

    Peter B, You start a very good thread. In the world of "commodity based" low bid design services, it is simple to throw out 85/95 as if something sent down from God and etched in stone. I agree--it is bogus, and primarily useful for specifying equipment in a simple way, quickly. I...
  6. PacificSteve

    Salt Water Pumping

    Thanks for al the replies...this project is still under development, so when I get to a selection, I'll let you all know what and why. Thanks PacificSteve
  7. PacificSteve

    Artic Master RMS-

    I would like to take a look at the kWH data, as well as a description of the changes made and equipment effected. Thanks steveolsen@hawaii.rr.com PacificSteve
  8. PacificSteve

    Artic Master RMS-

    The local utility did energy measuring before and after intallation of an ArticMaster and found no change in energy usage. I wasn't involved, but sure like the intuitive nature of real kWH measurements. PS
  9. PacificSteve

    Salt Water Pumping

    OK experts, here is a challenging one. I need to pump 1200GPM at 20 TDH saltwater at 70F, on a continuous basis. I am leaning towards a 316SS or Fiberglass type pump (at least until I hear from the pros). Main question -- can anyone hone me in a mnaufacturer that is likely to make a suitable...
  10. PacificSteve

    High Flow Low Head Saltwater Pump

    Economics is the drving force on efficiency We pay around $.20 per kWH at this site, one of the highest in the country. Just as example, if this is a 20HP pump, it would cost roughly $20,000 per year to run. Over 20 years, a 10% better pumping efficiency results in a $40,000 cost savings. Its...
  11. PacificSteve

    High Flow Low Head Saltwater Pump

    OK experts, here is a challenging one. I need to pump 1200GPM at 20 TDH saltwater at 70F, on a continuous basis. I am leaning towards a 316SS or Fiberglass type pump (at least until I hear from the pros). Main question -- can anyone hone me in a mnaufacturer that is likely to make a suitable...
  12. PacificSteve

    Chiller/water cooler info

    Clearly, no matter what energy usage and demand cost is, you would have a quick payback by going to a water cooled liquid chiller, maybe in the 200 ton range, maybe even higher depending on your building envelope and assumed industrial process generated heat. Pick a "large tower" to...
  13. PacificSteve

    Sound pressure level for new ACCU

    I will sure appreciate any help that you expert can provide. Design challenge: new aircon system, using ACCU, to be lcoated about 4 feet from the property line. The adjacent building (2 feet away from equipment) will act as a reflecting wall. I have Octave band and "sound level&quot...
  14. PacificSteve

    Infiltration value for cooling load calculation

    I am looking for a simple answer to a non-simple question. My cooling load program requires an entry for CFM/SF for infiltration. Building in question is a corrugated steel siding, and visual inspection shows it to be not so tight. 0.1 CFM/SF, maybe higher? Thanks PacificSteve
  15. PacificSteve

    CHW and domestic water pumping in high rise

    I am working on a mechanical retrofit project of a 40 story building, mixed residential and commercial. Could anyone provide the 3 top items for the "issue list" that will be important in proper redeisgn of this tall building (350'). Intent of redesign is replacement of aging...
  16. PacificSteve

    Tall Building HVAC systems

    I am working on a redesign of the mechanical components of a 40 story building with about 150,000 SF of residential condo and 75,000SF commerical (food service) What are the 3 biggest pitfalls that I could run into, compared to standard HVAC and DHW issues on conventional large (but not tall)...
  17. PacificSteve

    Vibrational loosening, steel bolt in aluminum threads

    solsen@pacific-energy.com Note the dash after pacific Thanks
  18. PacificSteve

    Vibrational loosening, steel bolt in aluminum threads

    The casting sits on top of a 2" Nominal pipe size stub up. is place on top of this stub up by the bolts only. The bolts have a standard head, however, the head does not come anywhere near the casting surface. i.e. the head of the bolt is in no way helping to stretch the bolt to preload...
  19. PacificSteve

    Vibrational loosening, steel bolt in aluminum threads

    Some clarifying information: The aluminum casting is threaded to allow the bolts to act as set screws. On each casting (there are a few varieties) there are either 4 bolts or 2 bolts. The Aluminum casting fails by brittle cracking that originates at the threads. I would say there would be...
  20. PacificSteve

    Vibrational loosening, steel bolt in aluminum threads

    I have a lighting bracket which is cast of an aluminum. This has been tapped, the thickness is 3/8". The manufacturer uses a galvanized steel bolt. This bolt screws through the aluminum casting and engages a 2" steel pipe, thus holding the fixture in place (or so the theory goes)...

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