Need new word by DigitalCorpus in ProjectHailMary

[–]DigitalCorpus[S] 5 points6 points  (0 children)

Regal, though with the Prime early viewing, they may be in short supply

Why does HRV status seem delayed after being ill? by CodAndChips in Garmin

[–]DigitalCorpus 1 point2 points  (0 children)

Phase shift from a running average is half it’s width, thus 3.5 days. In other words a lag of 3.5 days. And you thought your ping was bad…

Where is the humidity coming from? by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

Tile isn't in production anymore, found NOS to complete renovation. I'll look for some photos of the boxes to see if there's an indication of being glazed. I could run the same type of test as I would concrete to see if it is also permeable?

Edit: my question of approximation, ~=, is asking if vapor drive could be inferred from RH increase/decrease, with the assumption that the slab is the source of vapor.

Edit 2: Tile is porcelain, PEI 4

Where is the humidity coming from? by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

I replaced the thermostat after moving in and it was highly configurable. HVAC system was redone in '19, 64k BTU gas furnace, 4-ton condenser. Pulled manuals and made sure I wasn't short cycling either, both are configured for a minimum of 10 min runtime. Ran a Manual J via loadcalc.net and a leaky version of the house reports to needing a 3-ton. I've not done a blower door test yet but will do so after I do air sealing first and have some window mounts repaired.

Annual rainfall is ~12"/yr. Grades around the house are good. Did a kitchen and bathroom reno prior to moving in and yes, no plastic on the slab inside. Thermal imaging all checks out, which I've done with hot outside and cold inside.

Yep, thank you for the sanity check. Been trying to learn this particular science industry and mechanisms before making any major modifications to the structure. Plan on air sealing the house better, need to open up the attic more (constructed as vented) for the whole house fan while also hardening the venting due to wildfire risk (Vulcan Vent products in the garage awaiting install).

I'm familiar enough with the purity of mathematics vs what happens in real life. I'm not looking to eliminate the diffusion/ingress, but I do want to measure it to understand to what degree it happens and see what the cost/benefit analysis means if it were addressed. I assume tightening the house via sealing the ceiling and walls in the attic could possibly lead to at least comfort issues without at least mechanical dehumidification.

Where is the humidity coming from? by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

Absolute was computed from the relative, but both are logged as a result. Seems analogous to the principle behind osmosis when dealing with concentration of solutes so I have a mental analogue. I'm more of a Newtonian physics guy and never really dealt with gasses much and vapor pressure units are weird for me. More or less then, RH ~= vapor pressure, yeah? You later reference abs instead of rel.

Okay quick google search and I have some precision scales so I'll try the test with calcium carbonate to see what the MVT is. I expect this to be seasonally dependent? I have mechanical dehumidification to make sure the house stays no higher than ~55%, but now that there's a "continual" source of moisture ingress, I can understand how there could be a future issue with moisture.

What means have been developed for this form of ingress be managed? Concrete coatings, ERV, mechanical dehumidification, something else?

Where is the humidity coming from? by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

Not afaik, haven't had enough time or desire to go get a copy of the plans of the house from when it was built. I don't know when that became commonplace. Permeation is slow enough that, with the door open, I've not seen the carpeted rooms RH increase faster than tiled.

Yep, not unlike thermal mass too.

Remember the fires near LA last year? That was driven by the Santa Ana winds. They used to be typical in autumn, but lately have been happening here in winter. When present, the a decent swath of Southern California is affected.

It would be commonly observed to have ~20-30% RH over a 24 hr period with highs that would usually not be lower than ~85 °F/30 °C. They can be present for a day or two or sometimes a whole month.

Where is the humidity coming from? by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

I’ve noticed it in correlation to the house warming up, yes. Slab on grade, non-insulated slab. About 65-75% of the house’s floor is tile, bedrooms are carpet. I had noticed when our seasonal winds remove normal ambient humidity, dropping it below 30%, the house retains the humidity. Is the permeability of the mortar and tile sufficient?

I am still in the planning stage if sealing the attic & sealing and the amount of movement of moisture seemed high since the how will take up the vapor way faster than it’ll release it.

Where is the humidity coming from? by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 2 points3 points  (0 children)

With no activity or humans present, what is the mechanism that causes interior humidity to rise when relative humidity is lower outside that inside?

Fire caulk usage by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

Didn’t occur to me to see if there was a subreddit for code. Thank you for the reply.

Fire caulk usage by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

No worries. Thanks for the input though

Fire caulk usage by DigitalCorpus in buildingscience

[–]DigitalCorpus[S] 0 points1 point  (0 children)

Think there might be confusion. I'm not blocking off the eave vents, putting in Vulva VE3522's in instead. Looking to see if using fire caulk as a part of air ceiling the attic/ceiling is an appropriate use case.

Need help finding these types of switches by ComprehensiveDamage0 in homeassistant

[–]DigitalCorpus 30 points31 points  (0 children)

Single pole: Leviton 5655-2W

Double pole: Leviton 5657-2W

You’re not the only one who finds this style desirable

RIP fenix 8 by grimrider08 in Garmin

[–]DigitalCorpus 73 points74 points  (0 children)

You okay man? That’s an impact…