Recent Q&A

• Understanding Heat Pump Modes

  Hi all, I have a GreeFlexx Heat Pump, and noticed that it has three modes available: Standard/Conventional; Strong; and Energy Saving. The service manual describes energy saving mode as the…

• Duct Takeoffs on Supply Trunk

  Hi all, Can anyone tell me if there are any performance issues with having duct takeoffs not be centered on the supply trunk? Because of space constraints, it would be…

• Best way to balance a new system?

  Hi all,I just installed a new ASHP last week and redesigned/embiggened (thanks, Dr. Bailes, for the blog posts) the return ducts, but the supply ducts were left alone for now.…

• Duct Design Transition and Equivalent Lengths

  Hi all, I' m redesigning some of my rectangular (H/W=1) duct work in anticipation of a new air handler, and had a quick question regarding a large radius transition on the…

• Calculating for R-Value and Thermal Comfort

  Hi all, I’m planning on adding exterior insulation and air sealing to my house in CZ5, and am trying to find the right balance between more r-value and the cost…

• Sill Plate with Interior and Exterior Spray-Foam Insulation

  Hi all. More details below, but here’s the short version of the question: will a sill plate that has closed-cell spray foam for insulation on the inside (the conditioned, closed…

• Crawlspace Encapsulation Before or After Air-Sealing Returns

  我们住在1285年代q. ft. house built in 1958 in Boise, Idaho which is zone 4B. The crawlspace is ventilated to the outside, and has insulation on the foundation…