I was just at a home we installed the HPWH about a year ago and they're planning to remodel basement. I recommended to keep it in electric only mode during construction and have the crew use a room air filter too. What can you use condensate for?

This is completely nonsensical. The amount of static water when the tap is closed is no different (run by run) whether the manifold is in the first location or the last. the distance is the same. When you turn of the tap you're left with a run of pipe/tubing that will be full of water that cools off. The distance has not changed. Jesus this is pretty basic man.

One factor you didn't mention is that when you turn on the tap, hot water not only has to push all the cold water from the pipes, but it also has to heat up the pipes - hot water flowing through a cold pipe gets cold. This is why there's still some time after the water starts to feel warmer until it gets really hot. Smaller diameter pipes also get hot faster, and pex being a thermal insulator will be better than copper of the same diameter.

With a thermosiphon loop to my kitchen, the wait time is 3 seconds---this obviously could all be improved with smaller pipes, but I love not waiting and at no real cost.

You can also do a dual PRV: first one gets it down to 80, second one gets it down to 50.

Totally agree. I have merv 13's on my two ducted mini-splits and see PPM2.5 around 2 (Awair measured) most of the time and over 5 only when cooking. This in a 1903 house, next to the Port Of Los Angeles. 10 year old hvac system. When this system dies, my plan is: 1) 3 heat pumps rather than one shared, had leak once in one air handler. 2) replace attic ductless with ducted or better filtered. 3) hard ducting rather than flexi. Which brings me to the point: what was that hard ducting I saw in one of your previous missives and will it readily replace the flexible in an existing system? Happy New Year, in 32 minutes, we celebrate with EST because we cannot make it to midnight. ; ^ )

short story short, 2inch merv13 is better with airflow and filtration compared to 1inch?

10 min per hour oversize AND 30 min per hour your system is twice as big as it needs to be ... did you mean twice as small because your comments are illogical. Short time -- too larger. Research from various sources indicted -- Ideally, the fan should run for about 15-20 minutes per hour (or around 25-33% of the time).

How often shouldl this be done? You mentioned it had been 4 years on this clean. What is best practice?

Let me add to your great ideas. On initial construction of my house, my plumber had given me the strong advice to install a return pex line from the furthest point of usage in the house. Brilliant. Years after, I have installed a Grunfos recirculating smart pump that learns your habits and consume under 10 watts 95% of the time. It has now been 5 years, so let me tell you a fun fact that I have come to realize last year. First, I have to mention that I put the pump on sleep mode in the 3 seasons other than the winter to reduce un-necessary heat loss in the house. In the winter, the lost heat out of the pipes only contribute to the heating of the house, no waste here. A great feature on these smart pump is an anti-scale feature that makes the pump work for about 30 sec. a day. Great, less maintenance and longer life of product. The loop comes back to the bottom of the hot water tank, by what would normally be the scavenge drain. Well, last year, when I went to put the recirculating pump on the " summer mode or sleeping mode", I forgot to close the ball valves at the bottom of the drain going into the tank. Going in the shower, I noticed I still had instant hot water. That means that I don't even need a recirculating pump, as long as I allow the circulation in the loop system to happen, warm goes up, colder goes down just like density change with air, I have hot water all the way up. I obviously have learn to ensure I close the ball valves in the 3 warmer seasons to ensure I don't heat the house when I want to air condition it! I live in Montréal, fair winters...I hope this help the simplicity of your system and help save money!

Just revisiting this again - I think defrost efficiency is often overlooked and needs more attention. I'll just comment that the frost shown on your heat pump was very unlikely to form at 50F. but is rather from earlier when conditions were far more facourable for frost formation. Why defrost was initiated when it was is a more interesting question. Again I suggest the addition of temperature sensors for both ambient and coil temperatures to gain more information of the process of defrost. Also consider temperature measurements across the indoor coil to estimate COP.

A list of the items you used would be helpful and any other tips!

40 years ago, my father showed me how to push sand under a fiberglass tub and shower base.

Did you have a blueprint detailing the drywall? Drawings always stand up in legal proceedings

Epic man

Good idea.

Why are the easier to install?

Looks good! Curious, with the exterior intake being so close to the ground how do you keep the dirt/pollen/insects out of the comfopipe? Does the outside register have a filter?

What is the duct material you used?

Being in ATL what thermal efficiency gain do you expect from the InSoFast system? As in how beneficial is the foundation wall insulation vs no insulation. I see very little temp delta with an 8" poured wall all year long in the Southeast. So it's difficult for me to justify insulating.

Really enjoyed the video, Allison! One picky point about the supply side of the ERV ductwork. Zehnder ComfoAir Q ventilation units can be either right or left. In your case, we chose to have outdoor connections on the right and house connections on the left. The front left port in this configuration is indeed the supply to rooms, but it is so even if the sound-attenuating manifold is mounted incorrectly with the arrows pointing downward. So the arrows may not always indicate airflow direction: they mayst be installed correctly in minimize sound and maximize airflow. 😊

Have you considered putting mass loading sheets between the two layers of drywall? I found it to be very effective when having a “ hangout” room next to a bedroom. We also made sure to put at least one 90 degree bend in any common air conditioning duct work.

Do you have any idea on the impact on this? I'm curious how noticeable this will be.

Ridiculous video and thr manifold is stupid as there was no equal pressure to all the pipes

Alas, I have slab on grade. The shortest path from the water heater to my bathroom is via an external underground path. Digging under the slab isn't going to happen, and I don't trust the attic not to freeze.

Where I’m at, the supply comes in at the same wall location as one of my yard spigots. If I ever want to check incoming pressure I temporarily do it outside at the hose bibb. The PRV would be aft of that, so that I still have full pressure for the driveway (although more than 100psi seems crazy.) I saw another video with a second outside hose bibb for car washing … that was plumbed aft of a water softener.

Omg how have I never thought of or seen this. Game changer!!! 👏👏👏🙏🙏

If and when I get my bathroom fans vented outside instead of into the attic, my thought is to change the toilet light switch, the shower light switch and fan switch to be a smart switches, and the shower light to turn on the fan for an hour, and the toilet light to run the fan for 10 minutes. The venting is likely to be done the next time a Texas hail-storm destroys the roof.

Won't this reduce water pressure in shower and sinks from being smaller diameter pipes?

Hello, great video! A while ago Corbett Lunsford on his KZbin channel Home Performance did a video about PEX plumbing and one of the environmental experts he interviewed mentioned that most homeowners aren’t told by the manufacturers of PEX (and other plastic water pipes) that they should flush out their pipes by continuously running water through them for approximately 2 weeks after they are first installed in order to eliminate most of the contaminants leaching out of the plastic. Have you heard of this recommendation yourself?

Really clear and super informative, Allison. Bravo!

run times/off times summer set at 78 inside, 85-99 outdoor, 15 on/15 off/15 on/ 15 0ff = 30 min per hours is ok, i have been told by hvac people 1900 sf under air, cbs block, attic insulated, only 3 window direct sun,

Man I hate flex duct. Sure it can work, but it seems 8 out of 10 times it's installed lazily with way too much slack in it and run like a mess. The duct-o-puss is way too common now days. Ridged duct just seems so much less likely to have installer error.

Be careful if you have a regular HVAC company perform a Manual J calculation. In my experience most of them will fudge the numbers to get the results they think it should be. Then boom surprise, surprise the needed equipment is right around that 500 sqft per ton.

Is it OK to turn off your water when you leave your house for a couple weeks and not turn off the water heater? Is there any small amount of evaporation that over weeks will mean there is not enough water in the water heater?

Excellent vid Allison. Consider piping in a drain valve close to your main shur off, it just makes working on your system that much easier. I'm the only one that does this for residential plumbing.... I took the concept from fire sprinkler systems.

Well, aren't you handsome. 🙂

Thanks for the contribution. It will be great to see a video about manual j and s.

I'm going to add a circulation pump powered by the light circuit.

let's say you have a poorly sized system - how does one mitigate the issues without tossing the heating unit? Dehumidifier? ERV?

Why not BTUh per sq ft as a metric to gauge the quality of a design?

I have yet and have never found a properly sized system installed in the house yet. I’m still looking. That’s not even talk about undersized duct work . I think the last time I ever found a properly sized ductwork. Was when the original house that was built in 1940 had a gravity furnace, hard sheet metal ducting that was all wrapped in asbestos still excellent condition. Was designed for 160,000 BTU furnace . Design for a house with no insulation in the ceiling no insulation in the walls old wooden windows with the weights in the window sash. Most of the offshoot duct runs to the floor mount grills were 10 inch in diameter . The old house has had insulation blown into the walls, insulation blown into the attic. All the windows have been replaced with glaze vinyl windows. . And a contractor connected 40,000 BTU furnace directly to the 36“ x 28“ Plenum . Under this condition, it would be the most correct by accident overkill size ductwork that was original . . And 40,000 BTUs in a 1200 square-foot home in San Francisco is still way overkill and MORE than DOUBLE the size needed .

Congratulations on adding video to the mix! Some of my clients are a perfect fit for your content!! May I ask if one could do a rough version of a pressure drop with a standard probe or is it critical to use a static pressure probe?

Thank you Allison. I share your posts with lots of people, in the trade and out.

Is your basement above grade?

Thanks for the video. I didn't know a filter creates that much pressure drop in such a short amount of time. May I ask, how deep is your filter, 1inch, 4inches...?

I only have filters on my 3 return ducts, how could I measure a new filter since, like you said, i don't want to poke a hole in it. I'd also like to be able to measure intermittently to help determine when i need new filters. Haven't been able to figure this out, thanks!

Great video. InSoFast sounds good - however here's a puzzle for you - what to do with about a half-height CMU wall with no perimeter drain? I fear the CMU will weep and the foamboard will just lock in the water and make the entire assembly damp. Not sure how to think about giving the CMU an ability to try with an air gap while also getting the air sealing details right such that humid air never hits it, or how the assembly could work without a costly perimeter drain

At the intersection of construction and mechanicals, my house got into a horrendous wreck! I'm about an hour west of NOLA - any recommendations on skilled contractors?

Nice product, but it is more expensive than I expected (~8 per corner), and it also doesn't account for when there's a backdam. If there's time to let things cure, such as prepping windows on one day and then installing on the next, then I'd prefer a liquid flashing product and include a backdam in the design.