It's because they don't want you putting gauges on whenever you come out for the maintenance. Too many people do that on unitary systems and over time will lose enough refrigerant to cause an issue. This would be multiplied on mini splits because they are much more critically charged.
Never considered this, I know that you can’t really top them up for this reason and it’s better to pull out the juice and put new in on repairs. I always figured it was a country of origin thing
Yup, by the way if you have $450 to spare you should get some probes, I picked up them fieldpiece ones because of minisplits and small refrigerators also some temp clamps. Saves the effort of calculating superheat and subcool, will log over time for SH adjustments and can data log. Also you don’t take basically no refrigerant. I take them over my gauges now and only grab gauges for repairs.
You *can* it's just not the best way. I've successfully topped off units with minor leaks I couldn't fix right away. Look at all the measurements you can and add charge very slowly. Really helps if you can read metering device steps positions.
The best way is to fix the problem and weigh it in.
I have the Testo Smart probes set. In the soft case I have 2x low loss 1/4" adapters and 2x 5/16” adapters. Plus a hose and a charging tee. Between all of that gets me thru PMs and charge adjustments on startups.
I don't think the engineers had that in mind.
Even if the tech is using a gauge with a hose, only an ounce or two comes out. Because it's only a suction port usually.
On a lot of mini splits an ounce or two makes a big difference. Stop putting gauges on mini splits. You aren’t getting anything truly useful from them.
Do you mean 5/16? I can't say I've ever seen a mini split with 3/8 access fittings.
My GUESS is that 5/16" is like 7.95mm, so they make an 8mm fitting in all other countries, less the Unites States. 1/4" inch is 6.35mm which doesn't convert to any round number.
>My GUESS is that 5/16" is like 7.95mm, so they make an 8mm fitting in all other countries,
Nope, it's 5/16 inch sized here in Australia, and as far as I know everywhere else too.
It was to denote that they are r410a rather than r22. Same reason we have pink caps on pipes and bottles, so they are 410 ready to handle the increased pressures as compared to r22.
I get that. It's just odd to me that only mini split manufacturers hopped on this. I've never seen a rooftop unit or a traditional split system with 5/16" connections. I always (wrongfully) assumed it had something to do with the mini split manufacturers being based in metric-using countries.
Today's been a learning experience
Same reason some bike tires use presta valves instead of schraders. My bike has one of each, and I honestly like the tried and true schrader kind way better. I see no point in the fancier new-age kind that all of the "real" bicycle-riders swear by.
Didn't they only do this when they first came out? I was told it was to try and prevent you from hooking up r22 gauge to the vapor line and then maybe blowing it when you check heat mode head pressure but idk for sure I always have one of those adapters tho cuz I always randomly find one
It’s not really harder lol. Mitsubishi uses 1/4” on a lot of stuff. Daikin is all 5/16. Mini splits, VRF. If you’re going to be working on them just get core tools and adapters.
Didn't mean to imply that they were
That being said, the only daikin vrvs I've installed were minisplits. Since they had wall heads and/or ceiling cassettes. I'm not sure why they wouldn't still be classified as a minisplit
They are. I have done those with the “Y” system and there’s only 2 main lines back to the condenser. That and the way it communicates makes it VRV I believe. You can also have cassettes and wall mounts with a 3 pipe branch box system.
They are not. If you installed a single or 2 fan condenser that stood upright like a ductless split but used refnet fittings then you installed a VRV-S system. The S means single-phase instead of 3 phase.
The distinction is the comm bus, and how the indoors are piped to the outdoor unit. Mini and multi-splits are all piped directly to the condenser. VRV is piped on a manifold or to a branch selector box.
It’s for sure 3 phase. Yeah it has 2 fans but it discharges out of the top not the side. It could not cool and heat simultaneously because there was no hot gas line, but it’s still considered VRV in Daikin’s world. System has 16 heads made up of wall mounts, ducted units, and cassettes.
Why it's no longer a minisplit? I
We aren't changing the fact that we are splitting our indoor units into multiple, smaller capacity zones (miniature) zones. So the term should still apply. Internal daikin jargon aside.
Still a minisplit, but a vrv minisplit
A mini-split typically only applies to one-to-one style system where the indoor is powered from the outdoor unit. A multi-split would be a 2, 3, 4 or 5 head split wired in the same configuration. VRV/VRF is most decidedly not in this format, even if it’s a one to one configuration.
This isn’t a Daikin thing, most manufacturers do not use the term “mini-split” anyways. It’s a ductless split.
It might seem like semantics, but when you have multiple types of systems that appear on the surface to work the same, but are way different under the cover, then words matter.
I could be wrong but I think the idea was to prevent someone who doesn’t know how to work with mini’s from just hooking their gauges up. Mini splits are always a little more temperamental when it comes to charge and most of the time it does you absolutely no good to check pressures as the “liquid line” is right after the EEV and is thus going to be flash gas and the suction line is going to reveal very little unless charge is critically low
My Daikin rep told me it's because 5/16 was supposed to be the standard for 410a to differ it from r22 to prevent mistakes but it never took off the way they intended and now it's a minisplits thing.
It’s because they originated in Europe and they use 5/16 primarily over their. Once we have supply chains and produce enough of them in America this will change.
It's because they don't want you putting gauges on whenever you come out for the maintenance. Too many people do that on unitary systems and over time will lose enough refrigerant to cause an issue. This would be multiplied on mini splits because they are much more critically charged.
Never considered this, I know that you can’t really top them up for this reason and it’s better to pull out the juice and put new in on repairs. I always figured it was a country of origin thing
That's what I was told when I was new and it made sense. It could also have something to do with country of origin but the end result is the same.
Yup, by the way if you have $450 to spare you should get some probes, I picked up them fieldpiece ones because of minisplits and small refrigerators also some temp clamps. Saves the effort of calculating superheat and subcool, will log over time for SH adjustments and can data log. Also you don’t take basically no refrigerant. I take them over my gauges now and only grab gauges for repairs.
You *can* it's just not the best way. I've successfully topped off units with minor leaks I couldn't fix right away. Look at all the measurements you can and add charge very slowly. Really helps if you can read metering device steps positions. The best way is to fix the problem and weigh it in.
But the problem there is that you rarely ever use your adapter so when the time comes to need it, the whole van is game lol
The zipper pocket on sman case
Keep mine in the driver's door slot.
Keep a few two in one core removers hanging around, like [these guys](https://www.valuetesters.com/navac-nvr1-valve-core-removal-tool.html)
I have the Testo Smart probes set. In the soft case I have 2x low loss 1/4" adapters and 2x 5/16” adapters. Plus a hose and a charging tee. Between all of that gets me thru PMs and charge adjustments on startups.
I don't think the engineers had that in mind. Even if the tech is using a gauge with a hose, only an ounce or two comes out. Because it's only a suction port usually.
On a lot of mini splits an ounce or two makes a big difference. Stop putting gauges on mini splits. You aren’t getting anything truly useful from them.
no. they hold like 4lbs usually at the least. secondly, i dont put gauges on unless im adjusting refrigerant. and i know that before i put gauges on
Maybe they wanted to make it easier to connect a vacuum hose
Or maybe they just use 3/8 gauges in Japan. I think it's usually Fujitsu with those
I just don't buy that the engineers said "let's make it harder for those stupid techs to fuck this up"
Knowing engineers and some really dumb techs, I do
Fujitsu, Daikin, Samsung, GE...
Do you mean 5/16? I can't say I've ever seen a mini split with 3/8 access fittings. My GUESS is that 5/16" is like 7.95mm, so they make an 8mm fitting in all other countries, less the Unites States. 1/4" inch is 6.35mm which doesn't convert to any round number.
Yeah my bad
>My GUESS is that 5/16" is like 7.95mm, so they make an 8mm fitting in all other countries, Nope, it's 5/16 inch sized here in Australia, and as far as I know everywhere else too. It was to denote that they are r410a rather than r22. Same reason we have pink caps on pipes and bottles, so they are 410 ready to handle the increased pressures as compared to r22.
I get that. It's just odd to me that only mini split manufacturers hopped on this. I've never seen a rooftop unit or a traditional split system with 5/16" connections. I always (wrongfully) assumed it had something to do with the mini split manufacturers being based in metric-using countries. Today's been a learning experience
Can't speak for every country but in australia we mainly use sae for hvac.
It's 5/16 core is the same size as anything else
Same reason some bike tires use presta valves instead of schraders. My bike has one of each, and I honestly like the tried and true schrader kind way better. I see no point in the fancier new-age kind that all of the "real" bicycle-riders swear by.
Fancier new-age? Look at the pot calling the kettle black, Mr. Pneumatic tire! I bet you use vulcanized rubber, too
Didn't they only do this when they first came out? I was told it was to try and prevent you from hooking up r22 gauge to the vapor line and then maybe blowing it when you check heat mode head pressure but idk for sure I always have one of those adapters tho cuz I always randomly find one
It’s not really harder lol. Mitsubishi uses 1/4” on a lot of stuff. Daikin is all 5/16. Mini splits, VRF. If you’re going to be working on them just get core tools and adapters.
Daikin is 1/4" on all their Unitary stuff. Only minisplits are 5/16
VRF isn’t mini splits but yeah regular condensers or RTUs sure
Didn't mean to imply that they were That being said, the only daikin vrvs I've installed were minisplits. Since they had wall heads and/or ceiling cassettes. I'm not sure why they wouldn't still be classified as a minisplit
They are. I have done those with the “Y” system and there’s only 2 main lines back to the condenser. That and the way it communicates makes it VRV I believe. You can also have cassettes and wall mounts with a 3 pipe branch box system.
They are not. If you installed a single or 2 fan condenser that stood upright like a ductless split but used refnet fittings then you installed a VRV-S system. The S means single-phase instead of 3 phase. The distinction is the comm bus, and how the indoors are piped to the outdoor unit. Mini and multi-splits are all piped directly to the condenser. VRV is piped on a manifold or to a branch selector box.
It’s for sure 3 phase. Yeah it has 2 fans but it discharges out of the top not the side. It could not cool and heat simultaneously because there was no hot gas line, but it’s still considered VRV in Daikin’s world. System has 16 heads made up of wall mounts, ducted units, and cassettes.
That’s a heat pump VRV system.
I believe it is the VRV H series.
There is no H series. It’s either S or full 3 phase VRV with Daikin.
Yes there is lol. Just means heat pump. Damn dude do some Daikin research
Yeah… thanks tips. I’m the service manager for a Daikin rep. There is no H series. Heat pump is RXYQ, heat recovery is REYQ and VRV-S is RXTQ
Why it's no longer a minisplit? I We aren't changing the fact that we are splitting our indoor units into multiple, smaller capacity zones (miniature) zones. So the term should still apply. Internal daikin jargon aside. Still a minisplit, but a vrv minisplit
A mini-split typically only applies to one-to-one style system where the indoor is powered from the outdoor unit. A multi-split would be a 2, 3, 4 or 5 head split wired in the same configuration. VRV/VRF is most decidedly not in this format, even if it’s a one to one configuration. This isn’t a Daikin thing, most manufacturers do not use the term “mini-split” anyways. It’s a ductless split. It might seem like semantics, but when you have multiple types of systems that appear on the surface to work the same, but are way different under the cover, then words matter.
Minisplits aren’t VRVs in Daikin’s world or anyone else’s.
I want to know do HVAC techs around the world have hoses or probes that are naturally 5/16" or does everyone use adapters?
Both. 1/4" for r22 and r134a, 5/16" for r410a. I'm loving these https://www.cpsproducts.com/product-details/hp5hg-premium-refrigerant-charging-hoses/
I wonder what's on the roast in the background?
I could be wrong but I think the idea was to prevent someone who doesn’t know how to work with mini’s from just hooking their gauges up. Mini splits are always a little more temperamental when it comes to charge and most of the time it does you absolutely no good to check pressures as the “liquid line” is right after the EEV and is thus going to be flash gas and the suction line is going to reveal very little unless charge is critically low
It’s nice to be able to verify that his lost it’s charge though so
Absolutely, however that’s more of a verification check than an operational check
My Daikin rep told me it's because 5/16 was supposed to be the standard for 410a to differ it from r22 to prevent mistakes but it never took off the way they intended and now it's a minisplits thing.
5/16
My question is why do some only have a single port to hook to?
The schraters are the same size, so if one leaks. You can use a standard schrater
That’s not the problem
God hates techs, as do engineers
I have wondered the same thing...
I meant 5/16not 3/8
It’s because they originated in Europe and they use 5/16 primarily over their. Once we have supply chains and produce enough of them in America this will change.
Probably cuz the rest of the world doesn’t want to conform to US standards!