abc123puck
New Member
Hi,
My wife and I are working with an local architect group here in South Florida on a new home for our family. The home is approximately 5500 sq ft under air and will be on well water and a septic system. One ask I had of the engineers/architects was to try to a utilize heat pump water heater (HPWH) in the garage to help with energy efficiency and to provide some slight cooling/dehumidification for the space. We also valued somewhat timely delivery of hot water while limiting significant water waste, so I understood a recirculating system would likely be recommended. I understand HPWH aren't ideal for recirculating systems due to the ambient pipe heat losses (although the hot water and recirc piping will be insulated) and the demand placed on the heat pump, but I am willing to work around that by utilizing some smart controls on the recirculation pump (e.g., timer, temp control, etc.) and making sure the HPWH(s) are oversized if anything.
With that background, we received the attached plumbing design from the MEP engineers and I am trying to wrap my head around their hot water and dedicated recirculation design. My understanding is that the MEP firm has largely worked on commercial or multi-unit residential in the past to provide some perspective. The HPWH spec'd by the MEP is a single 80 gallon Rheem ProTerra unit. While I am not a plumber or MEP engineer, I have spent significant time trying to understand best practices for design of a recirculating system and am struggling with the complexity of this trunk and branch system and how appropriate balancing among the branches would occur. I wonder if limiting the dedicated recirc line to the two main trunks (presumably connected to the furthestmost point on each trunk) would simplify things both from a balancing and cost perspective while still providing hot water to fixtures in a somewhat timely manner. In addition, I feel that a single 80 gallon HPWH is undersized and wonder how a second unit would impact the most logical design for the system (e.g., separate loops entirely vs 2x units in parallel, etc.).
Here is a link to the plumbing design and home schematic if the attached images aren't high enough quality to see the details.
Any thoughts would truly be appreciated. Thank you in advance for you help.
My wife and I are working with an local architect group here in South Florida on a new home for our family. The home is approximately 5500 sq ft under air and will be on well water and a septic system. One ask I had of the engineers/architects was to try to a utilize heat pump water heater (HPWH) in the garage to help with energy efficiency and to provide some slight cooling/dehumidification for the space. We also valued somewhat timely delivery of hot water while limiting significant water waste, so I understood a recirculating system would likely be recommended. I understand HPWH aren't ideal for recirculating systems due to the ambient pipe heat losses (although the hot water and recirc piping will be insulated) and the demand placed on the heat pump, but I am willing to work around that by utilizing some smart controls on the recirculation pump (e.g., timer, temp control, etc.) and making sure the HPWH(s) are oversized if anything.
With that background, we received the attached plumbing design from the MEP engineers and I am trying to wrap my head around their hot water and dedicated recirculation design. My understanding is that the MEP firm has largely worked on commercial or multi-unit residential in the past to provide some perspective. The HPWH spec'd by the MEP is a single 80 gallon Rheem ProTerra unit. While I am not a plumber or MEP engineer, I have spent significant time trying to understand best practices for design of a recirculating system and am struggling with the complexity of this trunk and branch system and how appropriate balancing among the branches would occur. I wonder if limiting the dedicated recirc line to the two main trunks (presumably connected to the furthestmost point on each trunk) would simplify things both from a balancing and cost perspective while still providing hot water to fixtures in a somewhat timely manner. In addition, I feel that a single 80 gallon HPWH is undersized and wonder how a second unit would impact the most logical design for the system (e.g., separate loops entirely vs 2x units in parallel, etc.).
Here is a link to the plumbing design and home schematic if the attached images aren't high enough quality to see the details.
Any thoughts would truly be appreciated. Thank you in advance for you help.
