Retrofitting A/C sizing components correctly

[huramentzefix]

Nice forum that I came across here, I have spotted a lot of expertise.

I have a little Lada Niva which I would like to retrofit with an A/C system.
For the last 10 years I didn't have A/C at all, and I only really need it in the city in traffic.

What I am after is an A/C that is working great when being at an absolute still stand in city traffic.
I already have 2 bad-a fans installed.
The temperature is all year round in and around the 90° with humidity at 80% plus the extra heat that you get in the city when standing in traffic and tunnels without any air movement.

Condenser: I have a brand new "TYC 3569 Honda Civic Parallel Flow Replacement Condenser" here which woult easily fit. Is this any good?
I was looking at a "A/C Condenser for Kenworth T2000, T700, T800 / Peterbilt 367, 384, 386, 387, 388, 389, 587 QR" but don't know if there is a chance of fitting it?
(Update: just took measurements, the Civic condenser is the maximum size that I can fit)
Compressor: Thinking about buying a Four Seasons 88947
Evaporator: "Universal Evaporator, 5 Shutters 12V Double Shaft Evaporator, 12V AC Evaporator, 598CFM 20697BTU 3600rpm Speed"
But I was thinking going dual or triple evap and put two smaller ones, one under each seat?

Any thoughts, would this equipment do the trick?
Thanks I appreciate your guys help

[Tim]

Cond is large enough and, with proper airflow, should work fine.

Built-in Oil Cooler: No
Built-in Receiver/dryer: Yes
Configuration: Parallel Flow
Core Height (in): 14.89
Core Length (in): 26.38
Core Thickness (in): 0.63
Inlet Diameter (in): 0.61
Inlet Fitting Design: Block
Outlet Diameter (in): 0.4
Outlet Fitting Design: Block

[huramentzefix]

Thanks Tim I appreciate it.
Would the compressor be a good choice?

Has triple evap set-up be done before or am I halucinating?

I just thought that the compressor should have the capacity to pull the big condenser that I have postet + 2 small ones under the seats?
Or should the "Universal Evaporator, 5 Shutters 12V Double Shaft Evaporator, 12V AC Evaporator, 598CFM 20697BTU 3600rpm Speed" and one small "A/C 12V Air Conditioning Evaporator Assembly Unit, Heating & Cooling Evaporator, Under-Dash A/C Heating Cooling Unit with 4 Vents for Car Truck, hxcavators, harvesters, RV" in the read with hoses under the seats be enough?

I have taken the rear seats out, this is just cargo space.

Edit: I don't think that the "big" evaporator has 20697BTU cooling capacity with a stated 1.2 ton expansion valve and showing a 1.5 ton expansion valve.
Or is that cooling capacity plausible?

[JohnHere]

If memory serves, the GM HT6-type compressor has been used for front and rear A/C (two evaporators) in the Chevy Suburban and some other vehicles. Whether the HT6 can handle three evaporators, one main evap under the dash and two smaller evaps under the front seats, is open to speculation.

According to the specs, the compressor you mentioned has six cylinders and 164 cc's or 10 cubic inches of displacement. A Sanden equivalent, which has the benefit of no center case seam that can leak, has seven cylinders but slightly less displacement at 155 cc's or 9.5 cubic inches. I believe both compressors rotate in the clockwise direction when viewed from the front end of the clutch.

What year and model is your Lada Niva?

[Tim]

The original poster claims to have been blocked, but I don't see this in the log files. They are using a third-party browser, which I have no control over.

[huramentzefix]

The original poster claims to have been blocked, but I don't see this in the log files. They are using a third-party browser, which I have no control over.

Hi Tim,
I don't understand the term "third party browser", does the forum offer it's own browser?
Isn't everyone using a third party browser? Isn't firefor a second-party browser?
I am using the newest firefox.

Currently I am looged in through "proxysite"
It's an IP block on your site and has nothing to do with the browser.

[Tim]

The original poster claims to have been blocked, but I don't see this in the log files. They are using a third-party browser, which I have no control over.

Hi Tim,
I don't understand the term "third party browser", does the forum offer it's own browser?
Isn't everyone using a third party browser? Isn't firefor a second-party browser?
I am using the newest firefox.

Currently I am looged in through "proxysite"
It's an IP block on your site and has nothing to do with the browser.

In your email, you stated that you were going through some site to access the forum. That is what I am mentioning. Obviously, you are having IP issues using these proxies, which has nothing to do with our site. Please move on with your questions.

[huramentzefix]

If memory serves, the GM HT6-type compressor has been used for front and rear A/C (two evaporators) in the Chevy Suburban and some other vehicles. Whether the HT6 can handle three evaporators, one main evap under the dash and two smaller evaps under the front seats, is open to speculation.

According to the specs, the compressor you mentioned has six cylinders and 164 cc's or 10 cubic inches of displacement. A Sanden equivalent, which has the benefit of no center case seam that can leak, has seven cylinders but slightly less displacement at 155 cc's or 9.5 cubic inches. I believe both compressors rotate in the clockwise direction when viewed from the front end of the clutch.

What year and model is your Lada Niva?

It's a 2014

I am having problems acessing this site through my normal internet connection. Sometimes I can manage to log in using www-proxysite.com

I have read about the HT6 reliability issues and kept digging.
The compressor I want to purchase is the SD7V16 163.1ccm³ and is variable and runs at roughly 35°F suction.
It has a cooling capacity of about 7.5kW at 3000RPM 0°Superheat and 10°subcooling
At 4000 RPM it's about 9.5kW increasing with revs.
I haven't found the max RPM limitations for this model yet. But I don't really rev my car so I can play with the pulley size.
And I can read the speed signal via arduino and just switch the compressor off when I rev the car.
Like this the compressor can spin 3000RPM in idle and be switched off for 5 minutes or so when reved above 7000 RPM.

That is one small evaporator in this link here and they just increased the price from 50$.
I read that some say "32 passes" for the coil and and this one here 22 passes
I will be looking for 32 passes.
this under dash evaporator here has 6 vents this could be standing behind the seats blowing upwards and a small one for under the dash.

I think from the data that I have seen that the compressor is capable of supplying 3 condensers, but I am not an expert.
Would the condenser be large enough, my electric fans are super powerful, the sound like sirens. people are turning their heads and ask what that noise is when they kick in.

The variable speed compressor will adjust the refrigerant quantity based on varying load, which can be regulated via fan speed?

I think some of you experts here have suggested that the main evap should be installed with orifice tube and not TXV and the others can have the TXV.
Or should they all have TXV's in a system with variable compressor?
And then have one accumulator in the main return line, or have two accumulators in series because if more refrigerant in the system?
The variable compressor system requires less refrigerant than a fixed compressor?

Edit: I was just removing links to external sites because it is not welcome I have read?

[JohnHere]

It's a 2014
... .
I have read about the HT6 reliability issues and kept digging.
The compressor I want to purchase is the SD7V16 163.1ccm³ and is variable and runs at roughly 35°F suction.
It has a cooling capacity of about 7.5kW at 3000RPM 0°Superheat and 10°subcooling
At 4000 RPM it's about 9.5kW increasing with revs.
I haven't found the max RPM limitations for this model yet. But I don't really rev my car so I can play with the pulley size.
And I can read the speed signal via arduino and just switch the compressor off when I rev the car.
Like this the compressor can spin 3000RPM in idle and be switched off for 5 minutes or so when reved above 7000 RPM.

I'll try to answer at least some of your questions.

The SD7V16 is a Sanden variable-displacement compressor (VDC). The specifications that I have are as follows: Seven pistons with wobble-plate; maximum of 8,000 RPM; displacement of 160cc or 9.8ci; R-134a refrigerant and SP-10 oil.

I don't think you'll have to worry about revving your car to the compressor's maximum RPM.

That is one small evaporator in this link here and they just increased the price from 50$.
I read that some say "32 passes" for the coil and and this one here 22 passes
I will be looking for 32 passes.
this under dash evaporator here has 6 vents this could be standing behind the seats blowing upwards and a small one for under the dash.

Typically, the larger evaporator would go in front under the dash and the smaller evap(s) mounted wherever in the rear. But I wonder whether only an under-dash evap would be enough to sufficiently cool both the front and rear of your car since the cabin is fairly small volume-wise. Doing this would certainly simplify things.

I think from the data that I have seen that the compressor is capable of supplying 3 condensers, but I am not an expert.
Would the condenser be large enough, my electric fans are super powerful, the sound like sirens. people are turning their heads and ask what that noise is when they kick in.

Both the VDC (at nearly 10ci displacement) and the condenser you described would be large enough to run front and rear evaporators. I'm guessing that they're large enough to run three evaps as well, although I have no facts to back that up.

The variable speed compressor will adjust the refrigerant quantity based on varying load, which can be regulated via fan speed?

Yes, but let's take your thoughts a little further. The refrigerant quantity is fixed depending on how much (by weight) you initially install. Condenser and evaporator fan speeds DO have a bearing on how much refrigerant the VDC sends through the system, as does the compressor's RPM. But overall, it's the heat load, and subsequently, system pressures acting on the mechanical control valve, which determine this.

I think some of you experts here have suggested that the main evap should be installed with orifice tube and not TXV and the others can have the TXV.
Or should they all have TXV's in a system with variable compressor?
And then have one accumulator in the main return line, or have two accumulators in series because if more refrigerant in the system?
The variable compressor system requires less refrigerant than a fixed compressor?

Typically, a front and rear A/C system will have an OT for the front evaporator and a TXV for the rear evaporator. If you add a third evaporator, I'm unsure what type of metering device it would take.

I don't think a VDC system would necessarily take any less refrigerant than a fixed-displacement-compressor system.

[huramentzefix]

Thanks, I appreciate your help. You brought some light into the dark.

Typically, the larger evaporator would go in front under the dash and the smaller evap(s) mounted wherever in the rear. But I wonder whether only an under-dash evap would be enough to sufficiently cool both the front and rear of your car since the cabin is fairly small volume-wise. Doing this would certainly simplify things.

i totally agree. It would be easier. But I don't want to start a second time pulling the car apart if it isn't. I just need a T piece and some aluminium pipe to go to the rear evaporators or evaporator. and those can be on whatever fan setting needed, it doesn't has to be full speed. like this my front evaporator would be quieter too (not that it matters that much in a lada niva) but the fan speed could be lower.
These evaps are cheap as chips.

Both the VDC (at nearly 10ci displacement) and the condenser you described would be large enough to run front and rear evaporators. I'm guessing that they're large enough to run three evaps as well, although I have no facts to back that up.

thank you for your educated guess.
At a cost of a few pesos per evaporator I thought it would be easier to just install a third one since the car is pulled apart, and then regulate the system through the fan speed.
It's going to be a work truck install not a Maybach masterpiece.

Typically, a front and rear A/C system will have an OT for the front evaporator and a TXV for the rear evaporator. If you add a third evaporator, I'm unsure what type of metering device it would take.

Guessing; TXV. With more pressure build up you will have more flow through the evaporator.
The orifice is the "relief valve" till the evap ices up and no more refrigerant evaporates.
Then you will just pump liquid refrigerant back to the compressor which then evaporates in the suction line.
Is that not what the accumulator is for, to protect the compressor from liquid?

I don't think you'll have to worry about revving your car to the compressor's maximum RPM.

The idea was to simply play with the pulley. get it to a ratio of 1.7.
That is 4700RPM az 8000RPM and 1360 at 800RPM

Yes, but let's take your thoughts a little further. The refrigerant quantity is fixed depending on how much (by weight) you initially install. Condenser and evaporator fan speeds DO have a bearing on how much refrigerant the VDC sends through the system, as does the compressor's RPM. But overall, it's the heat load, and subsequently, system pressures acting on the mechanical control valve, which determine this.

If I understand it correctly then the maximum heat load determines the amount of refrigerant?
I have to fill the system by using subcooling to make sure that there are no bubbles in front of the orifice nor the TXV's?
The refrigerant in the supply line is a vapor at the compressor due to the heat, and is (has to be) a liquid in front of the orifice.

Do we know how the control valves control the compressor, is that superheat, subcooling, suction pressure, suction temperature or what?