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Mechanicals

  • Question & Answers

    High velocity trunk insulation – do I need it?

    New construction in Klamath Falls, OR. Note this is 4400' elevation, east of the Cascades, a high desert basin, not Portland!! We're using radiant heat with a high-velocity A/C-only ducted…

  • Question & Answers

    Zoning vs. multiple heat pumps

    TL;DR: for a central ducted heat pump system in a large house, is it better (performance-wise, more cost-effective) to use a single heat pump +/- zoning for each floor, versus…

  • Question & Answers

    HVAC replacement in ICF home–Hydronic A/C and radiant floor heat

    Hello! We have an ICF home in USA zone 6a, which is from -10°F to -5°F, or -20.6°C to -23.3°C in the winter. Our normal winters tend to be more…

  • Question & Answers

    1″ EPS foam board under hybrid water heater to dampen vibration?

    Rheem recommends placing something underneath their ProTerra hybrid water heater to prevent it from transmitting vibration into a raised, non-concrete floor inside a house.  They make a vibration isolation kit…

  • Question & Answers

    Conditioned crawl space HVAC help

    I live in british columbia and have a sealed crawl space with a high efficency natural gas furnace and an ICF foundation. The crawl is heated via the furnace. There…

  • Question & Answers

    How many fully ducted systems are really needed?

    Designing phase. 1340 sq ft ranch in 5a. Heating load will be around 18k.  Will a centrally located minisplit air handler do the job if supported by a fully ducted…

  • Question & Answers

    Range vent hood blower – troubleshooting

    Ten years ago, this house by renovated by a previous owner. The range hood was made by GE, although the blower was made by Best. According to GE, it typically…

  • Question & Answers

    410 vs 454b refrigerant

    hi, mechanical professionals ! I notice that neither mitsubishi nor fujitsu (both are common brands in my community) offers a “cold climate” heat pump compressor that allows any refrigerant other…

  • Question & Answers

    Help Pls: Mitsu Hyperheat final sizing decision

    Info: Air sealing done (-50% infiltration, 11 ACH > 5!), Attic ccSPF flash + Timberfill loose to R-50. Data taken through winter shows an actual heat load of 35k @…

  • Question & Answers

    Desuperheater – still economical?

    So a friend of mine who is a conventional HVAC contractor is trying to talk me out of a desuperheater as part of my geothermal heat pump, which will run…