Inverter AC Units and Electricity Bill

[redmanjp]

ppl also need to look at proper roof radiant barrier insulation or attic venting
properly installed it makes a huge difference

in other countries nobody builds a house without roof insulation

yeah this is very important in hot climates- keep a lot of the heat out to begin with and the bill is lower- i tested this at home- our new tv room area downstairs which has no upstairs but a roof on it has a radiant barrier and the temp reads 28-29C without AC during the hottest time of the day - upstairs with no radiant barrier it gets up to 30-32C. so that's 2-3 degrees hotter. the nights upstairs resemble the days downstairs.

[Chimera]

ppl also need to look at proper roof radiant barrier insulation or attic venting
properly installed it makes a huge difference

in other countries nobody builds a house without roof insulation

up to now i dunno how to install those radiant barriers properly, every tradesman and roofman and builder have something different to say

[pugboy]

all those foil bubble radiant barrier require an airspace at least 2" between the foil and the roof sheeting for it to be effective.
the way them roof experts install by pulling tight over the purlins then resting the roof sheeting over is the least effective way unfortunately because there will be little air space between the barrier and the roof sheets.
ideally they should let it sag between the purlins, or install under the purlins but that is troublesome way to install.

I have a large back shed which had no barrier installed and would get real hot under.
I installed the barrier under the purlins by using double sided tape and wood strips screwed to the purlins.
this way I got 4" air space.
the difference was night and day, felt like sitting under a big tree shade compared to before.

[nervewrecker]

i think the cost benefit ratio is going to be very different soon when TTEC rates raise- so ppl who planning to buy a AC now should definitely go with inverters.

Hempcrete, but like 10 years too early when I suggested it.

Start with heat insulation, then move on to heat removal.

7 times stronger than concrete, fire proof, reduces the nations carbon footprint, creates jobs in agricultural sector and will pollinate everyone female weed plant making it useless.

[redmanjp]

^ how much that cost?

[nervewrecker]

It's not approved, I pitched it to planning and development and min of energy, gathered some interest but didnt get very far.

Wanted to pitch it to proman as I saw they do their lil stuff in construction around for people (can't remember if was local), but who?

[Pyrrhus of Epirus]

The heritage is strong in here

[nervewrecker]

Why not just reveal yourself?

[gastly369]

*boombastick side eye

[nervewrecker]

Obi wan?

[nervewrecker]

It's not approved, I pitched it to planning and development and min of energy, gathered some interest but didnt get very far.

Wanted to pitch it to proman as I saw they do their lil stuff in construction around for people (can't remember if was local), but who?

https://www.habitat-tt.org/habitat-for-humanity-proman-collaborate-on-regiment-construction-training/

Ah, here it is, habitat for humanity.

Thing is, hempcrete isnt approved by the BOS, they said start with planning and dev. Complete waste of time.

[bluefete]

Abel has a sale on Katashi inverters 12btu - $3,500 + vat.

24 btu non-inverter - same $3,500 + vat.

Is that good? Which one to go with?

[redmanjp]

Abel has a sale on Katashi inverters 12btu - $3,500 + vat.

24 btu non-inverter - same $3,500 + vat.

Is that good? Which one to go with?

should be based on sq feet of the room - that determines how much btu u need but u dont want to oversize either. that 24btu might be cheap for its size but think about your TTEC bill especially when those rates raise. might be paying that same $3500 every 6 months

[Duane 3NE 2NR]

^ from what I heard the inverter units are only going to make a difference on units that run all day all night or close.
An inverter that runs for just a few hours like in your living room is not going to make any difference in your light bill.
Can anyone confirm?

[redmanjp]

^ from what I heard the inverter units are only going to make a difference on units that run all day all night or close.
An inverter that runs for just a few hours like in your living room is not going to make any difference in your light bill.
Can anyone confirm?

it's not just when turning it on that that the compressor turns on and uses a high amt of current - every time a non- inverter AC compressor kicks on (when the temperature in the room is rising) the same thing happens. so i would think even a few hours of inverter usage should make a difference as the non-inverter's compressor would have kicked on & off several times especially in the day.

[nervewrecker]

Conventional units have what's called a RLA rating on the side, or running load amperage. It's the amount of current the compressor takes to operate at given a specific refrigerant charge or load at a constant rpm.

It's like a grocery trolley full of goods is the load and the energy you exert to keep it moving at a specific speed is the current it draws.

For conventional units it's like you run up to the trolley and get it moving up to full speed in an instant. That initial amount of energy is the LRA or locked rotor amperage. It's just for the sake of explaining this.

Inverter types don't have a LRA and they have a RLA range as their speed and load can vary. It's like you start with a gentle push on the trolley and gradually get it moving.

For a conventional 12000 but let's say ball park figure is 5A RLA. An inverter might have that from 2.5 to 7A. If room is hot and unit comes on with a low set point the system may run at full tilt (7A) and gradually bring down the temp if it's sized appropriately. So if you run that for a short time you have successfully used more energy than it's counterpart.

[pugboy]

in other countries with expensive current it is the norm for all industries to install vfd motor controllers to avoid that hard run up

there is a swiss company with an office here who makes a mint supplying that

[nervewrecker]

in other countries with expensive current it is the norm for all industries to install vfd motor controllers to avoid that hard run up

there is a swiss company with an office here who makes a mint supplying that

VFD is one thing, eliminates drawdown on the supply at startup among other things, but when we start talking control for variables such as load we talking PLC and HMI and thats just not feasible for a mini split.

VFD has become almost standard in the industry for motor control coupled with the above mentioned where its cost is justified.

Inverter ac units are basically a VFD with a controller.

ABB btw, seen a few around. Some siemens equip as well

[pugboy]

yeah abb big in that

[bluefete]

Thank you for the responses and the question (Duane).

I do have 2 Toshiba Inverters - 10 btu and 12btu. The 10 btu does not cool like I want it to. It is in a small bedroom. The 12btu works really well for the room it is in - a larger bedroom.

My T&TEC bill averages about $700. every 2 months. The units are on mainly in the evenings. I cuss the most when the units have to service. 4 times a year by $300. each and I wonder why I have ac.

Also they are quite sensitive to dirt. So if someone is doing some work involving cement, gravel, sand, the 12btu clogs very easily.

I was thinking of getting a Katashi 12btu inverter to replace the 10btu.

Abel has a sale on Katashi inverters 12btu - $3,500 + vat.

24 btu non-inverter - same $3,500 + vat.

Is that good? Which one to go with?

should be based on sq feet of the room - that determines how much btu u need but u dont want to oversize either. that 24btu might be cheap for its size but think about your TTEC bill especially when those rates raise. might be paying that same $3500 every 6 months

^ from what I heard the inverter units are only going to make a difference on units that run all day all night or close.
An inverter that runs for just a few hours like in your living room is not going to make any difference in your light bill.
Can anyone confirm?

it's not just when turning it on that that the compressor turns on and uses a high amt of current - every time a non- inverter AC compressor kicks on (when the temperature in the room is rising) the same thing happens. so i would think even a few hours of inverter usage should make a difference as the non-inverter's compressor would have kicked on & off several times especially in the day.