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View Full Version : i,m new to this vrv game !



eggs
13-08-2004, 11:27 PM
i run a small a/c company, and have recently quoted for my first vrv job.
although over the years i have fitted many, both as an employed and sub-contract engineer (mainly mitsu elec)i have never looked into the cost of them much.
Appx how much should i be paying for a 18hp condensing unit,15, 2.5kw wall mounts and 2, 10kw 4 way blows.
i dont mind which mitsu i use,i like daikin, hitachi give me a lot of support when i need it.
i just need a pointer as to the price.

can anyone put me in the picture.

cheers

rbartlett
14-08-2004, 05:47 AM
this one seems a tad strange

you run a small a/c company so it's safe to assume you've already fitted splits thus far and therefore have access to the usual suppliers/prices etc

then you say you have quoted a vrv job -but you don't know how much the kit costs??

hhmmmm.....


cheers

richard

Peter_1
14-08-2004, 09:20 AM
Or he is an end-user who wants to know how many margin his installer takes :confused: :eek: .

Karl Hofmann
14-08-2004, 07:01 PM
Eggs,

How on earth did you quote for the job without knowing how much the kit would cost to buy??

No way would I use something that is new to me without involving my supplier to check that my application is correct.

Brian_UK
14-08-2004, 10:40 PM
I agree with you all folks. Mind you looking at the typing (lack of capital letters, spacing, etc.) :rolleyes: maybe he is the Director of a small Company; first time at the keyboard perhaps :p

Peter_1
15-08-2004, 08:14 AM
Strange we see now reply from easter..!

Karl Hofmann
15-08-2004, 12:41 PM
It's the eggsact respose that we would eggspect :D

frank
15-08-2004, 01:01 PM
vrv - what's that :D

chemi-cool
15-08-2004, 03:22 PM
After all the "support", the poor guy will become a plumber ;)

Chemi

eggs
15-08-2004, 06:46 PM
you are correct, i do have all my usual suppliers.
the point of my question is :
i, quoted the job using a mixture of splits and multi's.
then i went out for the vrv/vrf prices, out of curiosity to see if i could offer my customer a better system for a similar cost.
the prices i got back were about 25% higher for the kit.
is this about right.
is £175000 the norm for the system i mentioned in my first post ?
ok my grammer and punctuation are not the best, as i am an engineer, trying and learning all the time to run a business.
maybe one day i will be able to employ a silver tongued cavalier to do all my admin/sales/estimating work, but for now it's just me.
all i wanted to ask was a little bit of information from all you sharp suited, obviously far superior company managers and engineers.

thats all.

cheers friends.

Latte
15-08-2004, 06:55 PM
Hi Eggs,
I havn't had a large amount of exposure to VRV/VRF's but what i have found out is they they are a strange beast and best left to the Bigboys (Size of company Marc, dont get excited).

I assume if you are quoting for installation then you are also putting in a service/maintainence quote as well. Personally i would stick with what you know best, that way if you hav any probs you should be ok and keep the customer happy.

obviously if it's also cheaper that way, then there's another reason

Regards

Raymond

chemi-cool
15-08-2004, 06:58 PM
If you would put that in the same words at the beginning,
everyone here would go out their way to help you. :cool:

My apologies. didn't mean to hurt.

Your local (Europeans) friends will come soon for your help.

Chemi :)

eggs
15-08-2004, 07:37 PM
thanks for the civil reply's, i thought for a minute i had posted to alt.hvac by mistake.
just to introduce myself properly.
i,m an a/c installer, who got fed up of slaving for others.so i set up a company with my mate.i am not very good at the clever side of the business (fault finding etc) but my mate (co-owner) is.
he is a refrigeration engineer(good at service and maintenace etc) and i am an a/c engineer (my forte is installation, fast, neat and efficient).
between us we are learning the rest of the business fast.
we have been established for 2 years now.

sorry if i misguided anyone into thinking i was an end user trying to snoop into "OUR" margins.

cheers

eggs

rbartlett
15-08-2004, 09:01 PM
vrv will always be dearer than splits/multi's..

the reason we spec vrv's is usually for architects love 'em ,big big business likes the energy saving potential (although given the much higher maintenance repair costs down the line this is very debatable) and outdoor unit space dictates..

apart from that they are bloody expensive to supply/install/maintain/repair

always always go for the full heat/cool option as customers feel cheated if some geezer in an office up the corridor can dictate if they get heating or cooling that day

it's silly to ask if 175k is the right price as we haven't a clue what the job entails etc...

cheers

richard

eggs
15-08-2004, 09:22 PM
oooops typo

17.5k not 175k (silly me)

that is what i have been quoted for the kit

cheers

eggs

rbartlett
15-08-2004, 09:46 PM
17.5 k

not a big vrv job then..

cheers

richard

benncool
16-08-2004, 05:54 PM
Okay, time for some translation for the Colonies. VRV is that the same equipment(kit) that we call ductless splits? :confused:

Peter_1
16-08-2004, 07:31 PM
No, Variable Refrigerant Volume (name patented bij DAIKIN) or VRF (Mitsubishi) Variable Refrigerant Flow.

1 outdoor unit, sometimes two in master slave combination, compressor frequency controlled and till 16 and even more indoor units connected to it on a main suction, a main liquid header andsometimes a main discharge header.

Some sort of an 'airco-pack', nothing more.

Some can heat spaces with the heat they extracted in spaces which were to hot( North/South orientation of the building)

(Very) Expensive, full of electronics,... I don't like them.
Instead of a manifold to service them, you need a portable PC, gateways, special cables, .. You even don't need a manifold anymore.

benncool
16-08-2004, 08:02 PM
Oh yes, I did see a presentation of these by Mitshbishi. They haven't caught on here as of yet. They are kind of limited in sizes as I recall. We would typically use water source heat pumps in the type of applications that these new Mitshbishis are designed to do.

Thanks for straighten me out on this.

rbartlett
16-08-2004, 08:09 PM
whichever way you look at it they are fantastic bits of kit..i remember first seeing the two pipe simultaneous heat/cool system mitzi bought out in operation and being mighty impressed

cheers

richard

frank
16-08-2004, 08:09 PM
(Very) Expensive, full of electronics,... I don't like them.
Instead of a manifold to service them, you need a portable PC, gateways, special cables,

Peter

They are really good bits of kit. When you understand the logic of the electronics and you stand there watching them cycle, offload, ramp up etc: you tend to wonder why the rest of the refrigeration equipment doesn't employ the same sort of control. Even better when you connect the laptop and watch what is happening.

Peter_1
16-08-2004, 08:54 PM
They're of course a marvelous piece of technique, infact more of electronics but if you haven't your PC with you and you come there on a cold winter morning and you only here a very strange and silent humming in the compressor,...well... the first time,.. I searched a long time before the technical service of Mitsu said that this was the warming up of the oil in the sump via a small DC voltage direct on the windings.

I liked it more the old fashioned way: thermostat controlled a relay and all the safety devices where connected in line with the relay.
Now, you can't measure almost nothing anymore and I even know pretty much about electronics.

As long as it works, it's OK but as soon as something goes wrong, then the PCB replacements can begin, without knowing in fact what you're doing.
You don't have to be a good tech to service these things. YOu only must be able to losen connectors on the PCB's.

You can't pinpoint the problem anymore like we could in the past.

I once was proud with some Mistu's: we installed 3 VRF's in a building and the electrical contractor was far behind schedule.

We started up on a long cable we trown through the window, to the switch-cupboard in the basements.
We did the run-up on this cable and started up everything.

The electrical contractor then layed the final cable and didn't called us for this.

But,...his apprentice had connected the neutral blue wire to the lines.
Result: 9 PCB's of indoor units were blown up.

Mitsu technical came and the said : well,... you need 9 new PCB's at an end user price of - I forgot the correct price - something around 750 € piece.
This was anyhow something for the insurance company they said.

But... I took a PCB and looked closed to it.
From the 9, 7 of them I could repair with only changing the varistor on the income of the mains on the PCB.

We charged 30 €/varistor (real cost perhaps something around 1 €) and around 3 hours work/PCB (real work +/- 30 minutes) , so we maked good money then but so did the insurance company (and they were aware of this)

We then also made of course an agreement with the insurance company that the client still got his 3 years warranty on the PCB's in case one failed later due to this repair or not.

But anyway, .. that's the modern world we're living in now, the 'don't-repair-but-throw-away-society'.

They're expensive: make the next time when you make a quote a comparison between a VRF and independent units.
With a VRF, when the outdoor unit fails, the whole building is without cooling, with independent units, only 1 room.

And if you don't offer the R2 but the cheaper Y series, I garantuee you problems the moment the seasons switches from a cooling-need season to a heating-need season or vice versa. The complaints will start always the same "we ask for cooling and it won't work,... but in office 2, there it's still heating'
Stupid you have to say then: "Switch everything off and start the 'problem-room' first up in the desired mode. It will work fine then"

Reason we never switch computer rooms to the VRF, always an independent unit.

Peter_1
16-08-2004, 09:07 PM
Another Example: we installed last winter 3 bigY's.
One of the 3 is constantly tripping on - I don't know the correct name for it - earth leak protection (ELP).
Sometimes, once a day, sometimes once a week.
Sometimes when it's sunny, sometimes when it rains.

You can't megger almost nothing and it's also dangerous.
We replaced the outdoor fan.

We now installed on every indoor unit an ELP of 30 mA, between the fans, between some SV's, changed the main ELP to one of 300 mA.
This is not the way a good tech solves such a problems.
Even the Belgium importer don't find it. even not with his PC !! :D :D :D :D

frank
17-08-2004, 07:57 PM
Reason we never switch computer rooms to the VRF, always an independent unit.

Got to agree on that one - server rooms should always be independant :)


I liked it more the old fashioned way: thermostat controlled a relay and all the safety devices where connected in line with the relay.


I agree, but I do like the VRV kit, especially the new R410a systems. Superb! :D


But,...his apprentice had connected the neutral blue wire to the lines.
Result: 9 PCB's of indoor units were blown up.

If you switch on one of the new Daikin VRV II systems without the neutral wire connected then you can kiss the PCB's goodbye. :D

rbartlett
17-08-2004, 08:03 PM
a friend of mine would always use numbered Y-Y cabling but insist on belling every one before he wired up final connections..

anyway last heard he's commissioning for mitzi..good guy -lousy head gear..

cheers

richard

eggs
17-08-2004, 09:33 PM
bollox to it, i'm fitting the splits.

cheers

eggs

Latte
17-08-2004, 09:57 PM
Hi Guys,

First of all Eggs i hink you have made the right choice.

Now, I havn't had much to do with VRV/VRF so can someone tell me as simple as possible or show me a link to a website how it works. Obviously a/c systems on cool and heat easy enough to work out, system just cycles the other way but how does it work on a VRV/F when you can have some indoor units on heat and some on cool. Does the system somehow used the evaps on heat as condensers ? or is it far too technical to explain simply.

Regards

Raymond

Brian_UK
17-08-2004, 10:27 PM
If I remember correctly Raymond, the Mitsi uses three pipes, hot gas, liquid and suction gas. In the 'black box' (I can never remember what they call the splitter box - is it BC ?) there are a range of EEVs and solenoids which can then distribute whatever is needed by the local unit. It can also recover heat or cool from one unit to the next if needed.

I'll try and dig up some more 'correct' terminology.

rbartlett
18-08-2004, 06:22 AM
brian your memory is inflating the amount of pipes a mitzi needs..

as i mentioned earlier it is a 'two' pipe system ;-)

here's a link (or two) from a v.good mitzi page

http://www.bdt.co.nz/citymulti/how-2-pipe.asp
http://www.bdt.co.nz/citymulti/od_r2.asp

cheers

richard

Peter_1
18-08-2004, 06:26 AM
And one of Mitsubishi Heavy http://www.3dair.co.uk/download-files/r407c-guide.pdf with a lot of other info

benncool
18-08-2004, 07:15 PM
I recall now why I didn't take much interest in this varible speed compressor system. I think the reason we don't see them here in Northeast America is because our winters are too sever.

A building that is 2000 sq. ft would take approx. 60,000 buth to cool it in the summer and approx. 120,000 btuh in the winter to heat it. So in this example I would have to chose a PURY-80MU system

This would give me 76,400 Btus cooling and only 85,300 heating. The cooling would be over kill and I would have to use auxsiliary heat in the winter. In our area oil and gas is much more inexpensive to heat with than is electricity.

frank
18-08-2004, 07:39 PM
In our area oil and gas is much more inexpensive to heat with than is electricity.

How can you say that with a COP of around 3.5:1 on electric VRV? What's the COP on your gas or oil equipment?

Peter_1
18-08-2004, 11:00 PM
How, how, ... we heat our offices with a PUHY. A COP of 3.5 you said???
If you're satisfied with 18°C inside when ambient is +/- 10°C perhaps???
Calculate once at -10°C outside and 22°C inside. While running, the COP is then perhaps 2 or less but when it goes each 20 to 25 minutes in defrost, well... ou're average COP is shrinking like snow in the sun.
When we need to calculate for heating, we always take the 1 st figure in the manual (evaporating at -10° instead of 0°C or 7,5°C) Then we're sure that out heatpump has enough power to heat the building when the heat-losses are the greatest (outside -10°C when they need 22°C in the building)
That's evaporating in the best case at -14°C or -15°C. The moment you need the heat the most, nature is giving almost no energy anymore. Evaporating at 7,5°C is not a realistic figure. And when it goes in defrost, the fan is running at a very low speed, you will the cold coming out the units and all that cold has to be warmed up afterwards.
This is the second year we heat with the PUHY and we seriously think to install a central water heater, fired with gas and with litlle duct water heaters installed in the excisting ducts.

benncool
21-08-2004, 03:19 AM
Yes Peter hit the nail on the head. When you get into outdoor temperatures that are below 0 deg C then heat pumps and thier COPs really are out of the picture.

It is a great concept to be able to move heat from the outdoors to the indoors using the principles of refrigeration. But when there is very little heat outdoors to move indoors then the whole theroy falls apart.

It is kind of like eating a bowl full of lettuce and calling it a hearty meal.

Peter_1
21-08-2004, 08:59 AM
This has nothing to do if Benncool is an American or not. This is only a personal view. I think some better don't read alt.hvac anymore because they slowly taking over the very bad habits of some there without realizing it themselves.

We, ...and we're not Americans, installed in our offices a PUHY with a separate kWh counter on it, have the practical experience now with it each day.

But from next winter on, we will only use it for cooling and will install a gas burner before the real cold comes.
That will be much cheaper to heat.

Another one:
When you install a heatpump in your house, shop, house... and you uses it as your primary heating, they refund you a certain amount.
When everything is installed, someone of the electricity company comes - in this case Marc I know realy well- to check if you indeed have installed a heatpump and sign the papers then afterwards for the refunding.

Marc's wife has a shop and he needed an airco for this. He contacted us and we installed it.
He heats the shop now with gas and installed an only cooling unit.
He's seeing each day that heatpumps are not that efficient as the manufacturers and his boss (the main Belgium electricity company) promise.
A heatpump is a nice piece of technique and a good example of using the nature resources ....to a certain level. If you go below that level, then it's not economic anymore.
As long as you have a source of above 5°C, then it's OK.

When we build our new house 12 years ago, I installed two heatpumps air/water. I modified a lot to increase efficiency.
After two years, we installed a central gas burner and since then, we're heating much more economically (+/- half the price!!) and... we finally had comfortable temperatures inside our house.

Latte
21-08-2004, 09:43 AM
What is this alt.hvac i keep reading about :confused:

Regards

Raymond

rbartlett
21-08-2004, 10:10 AM
newsgroup alt.hvac used to be THE place to dicuss..then came fridgetechs' discussion then this..

no alt.hvac is frequented by mainly redneck neocons domestic hvac'ers who flame anyone en mass who dares to disagree with their out of date backward way of thinking..i positively enjoy the place..;-)

cheers

richard

Tates_uk
22-08-2004, 02:00 PM
I agree with you all folks. Mind you looking at the typing (lack of capital letters, spacing, etc.) :rolleyes: maybe he is the Director of a small Company; first time at the keyboard perhaps :p

I'm the Co-Director of a small company and as you can see all my punctuation is correct. :confused: I think....!

Any way, you don't need brains to quote work, just a bloody good spellchecker!

rbartlett
22-08-2004, 02:21 PM
I'm the Co-Director of a small company and as you can see all my punctuation is correct. :confused: I think....!

Any way, you don't need brains to quote work, just a bloody good spellchecker!


'anyway' is one word ;-))

or it is in this context

ie 'I can't go anyway' means 'I cannot go whatever'

'i can't go any way' means 'I'm unable to proceed'

class of '77 c.s.e grade 4

cheers

richard

Peter_1
22-08-2004, 07:09 PM
Here we go again. :(

iceman007
23-08-2004, 01:17 AM
I just read this thread.

£175,000 ? for the kit. I would't pay that for my equipment, but my trade discount is quite good. We are approved installers for one certain manufacturer, but because of that we get very good prices.

Tates_uk
23-08-2004, 01:10 PM
'anyway' is one word ;-))

or it is in this context

ie 'I can't go anyway' means 'I cannot go whatever'

'i can't go any way' means 'I'm unable to proceed'

class of '77 c.s.e grade 4

cheers

richard

There's always one...............!!!!! :p

benncool
25-08-2004, 10:03 PM
Well maybe I didn't make myself clear. Back in the 1970's manufacturers tried every variety of heat pump system that you could imagine here in the heavily populated northeast US.

It is just too darn cold. Any temperatures below 0 deg C just could not keep up with the heat loss of the building. Any heat pump system would need auxsilary heat. That auxsilary heat had better not be electric heat if you live around here.

In our State(Vermont) you would not get a building permit if you listed that you were going to install electric heat. The power company is forbiden to connect to your building if you use electric heat. A heat pump system, alone, would not be able to heat a building in this area.

benncool
26-08-2004, 01:00 PM
A dimensionless statment. Like saying a piece of string just isn't long enough in the North.

In this business cost is always a factor. For any GIVEN building in this locale it is not financially feasible to heat with a heat pump system. In order to heat a building (of a given size) with unassisted heat pumps you would need equipment that could do twice the cooling that is required for the same building in the summertime. So then the question arises, "Why do I need this big machine to cool my building?" The design engineer would have to reply, "So you can heat your building in the winter time." Then the owner would say," wouldn't it be less expensive to install and operate a smaller cooling system and a gas fired furnace for heating?" The answer is a diffinate yes.

Now it would be nice if we could build buildings with 0 heat loss. But there again money is an issue--not to mention health concerns.

Don't get me wrong. I like the Mitsubishi technology with the varible speed compressor but #1 they are expensive. Number 2 it would be a tough sell in these "parts of the woods" because or earlier failed attempts to introduce heat pumps.

benncool
26-08-2004, 01:17 PM
A dimensionless statment. Like saying a piece of string just isn't long enough in the North.

Okay, in order to put dimensions on my statement let me sum it up this way; In order to heat a building in my area with unassisted heat pumps it would take equipment that had twice the cooling capacity than that would be needed in the summertime.

frank
26-08-2004, 08:04 PM
Okay, in order to put dimensions on my statement let me sum it up this way; In order to heat a building in my area with unassisted heat pumps it would take equipment that had twice the cooling capacity than that would be needed in the summertime.


Is that a guess or have you done the calculations?

A heat pump should be selected on the greatest demand either heating or cooling

benncool
26-08-2004, 09:38 PM
Is that a guess or have you done the calculations?



I am this company's estimator so you know it is a wild a$$ guess. :D

Peter_1
26-08-2004, 10:23 PM
Is that a guess or have you done the calculations?

A heat pump should be selected on the greatest demand either heating or cooling

Same figures here Frank, especially if you calculate heatloads according to the Belgian law which is -10°C outside and 20°C inside. Even the new EN law gives almost the same figures.

As I said previous, I had a water/aor heatpump in my house and replaced it after 2 years. The bill for heating was afterwards divided by more than 2.

stephenjsmith
09-10-2004, 11:55 AM
Well at least the guy got some response from you guys even if its not what he expected lol :D