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Date: 05 Apr 2007 13:34:34
From: yoma
Subject: HX Seasonal adjustment

Just wondering whether it's not uncommon to seasonally adjust the
pressurestat on a HX machine?

My faema E98 (Cimbali group) is plumbed in - and in the winter months I
have to up the boiler pressure to 1.3+ bar, from around just under 1.2.

This is based on my personal taste, rather than measuring the temp. out
of the group head.




 
Date: 05 Apr 2007 07:44:34
From: daveb
Subject: Re: HX Seasonal adjustment
On Apr 4, 11:34 pm, yoma <y...@yoma.net.au > wrote:
> Just wondering whether it's not uncommon to seasonally adjust the
> pressurestat on a HX machine?
>
> My faema E98 (Cimbali group) is plumbed in - and in the winter months I
> have to up the boiler pressure to 1.3+ bar, from around just under 1.2.
>
> This is based on my personal taste, rather than measuring the temp. out
> of the group head.

why would you need to?

If you WANT to, great!

dave

modded HX expert



  
Date: 06 Apr 2007 08:44:32
From: yoma
Subject: Re: HX Seasonal adjustment
daveb wrote:
> On Apr 4, 11:34 pm, yoma <y...@yoma.net.au> wrote:
>> Just wondering whether it's not uncommon to seasonally adjust the
>> pressurestat on a HX machine?
>>
>> My faema E98 (Cimbali group) is plumbed in - and in the winter months I
>> have to up the boiler pressure to 1.3+ bar, from around just under 1.2.
>>
> why would you need to?

Under-extracted taste (as winter comes on).

The water comes in via plumbing directly from outside the building. The
tap water temperature from the same outlet varies considerably b/w seasons.

Should a HX machine be this sensitive?

>
> If you WANT to, great!

Not a case of WANT to, but 'have to'.

>
> dave
>
> modded HX expert
>


   
Date: 05 Apr 2007 23:14:25
From: Espressopithecus (Java Man)
Subject: Re: HX Seasonal adjustment
In article <46157BD0.5080401@yoma.net.au >, yoma@yoma.net.au says...
> daveb wrote:
> > On Apr 4, 11:34 pm, yoma <y...@yoma.net.au> wrote:
> >> Just wondering whether it's not uncommon to seasonally adjust the
> >> pressurestat on a HX machine?
> >>
> >> My faema E98 (Cimbali group) is plumbed in - and in the winter months I
> >> have to up the boiler pressure to 1.3+ bar, from around just under 1.2.
> >>
> > why would you need to?
>
> Under-extracted taste (as winter comes on).
>
> The water comes in via plumbing directly from outside the building. The
> tap water temperature from the same outlet varies considerably b/w seasons.
>
> Should a HX machine be this sensitive?
>
Do you flush the brewhead/HX before pulling your shots? The technique
described as "watching the water dance" should eliminate any need to
change the pstat setting seasonally.

Rick


    
Date: 06 Apr 2007 10:08:49
From: yoma
Subject: Re: HX Seasonal adjustment
Espressopithecus (Java Man) wrote:
> In article <46157BD0.5080401@yoma.net.au>, yoma@yoma.net.au says...
>> daveb wrote:
>>> On Apr 4, 11:34 pm, yoma <y...@yoma.net.au> wrote:
>>>> Just wondering whether it's not uncommon to seasonally adjust the
>>>> pressurestat on a HX machine?
>>>>
>>>> My faema E98 (Cimbali group) is plumbed in - and in the winter months I
>>>> have to up the boiler pressure to 1.3+ bar, from around just under 1.2.
>>>>
>>> why would you need to?
>> Under-extracted taste (as winter comes on).
>>
>> The water comes in via plumbing directly from outside the building. The
>> tap water temperature from the same outlet varies considerably b/w seasons.
>>
>> Should a HX machine be this sensitive?
>>
> Do you flush the brewhead/HX before pulling your shots? The technique
> described as "watching the water dance" should eliminate any need to
> change the pstat setting seasonally.
>

Yes.
And the water dance varies depending on how hot/cold the weather is.

I think this is the case with all machines - and is a measure of the
heat loss of the group head as a well as the water coming out of the HX.

Anyhow couldn't the flushing actually compound the problem? The flush
would remove the 'overheated' water. Then fresh water coming into the
HX could be very cold/hot.

Maybe turning up the pressurestat compensates for general heat loss in
the group head, which makes just as much difference?

Of course all this may not apply, for a machine in an air-con building
with plumbing already having run some length indoors,

Thanks
-Yoma
Maybe this is one contributing factor from:
- room temp.
- boiler temp.
- water input temp.

A tanked hx machine in an air-conditioned room would lose less heat,
it's water input would be warmer than a plumbed hx machine in a cold
workshop.


     
Date: 08 Apr 2007 23:22:35
From: Espressopithecus (Java Man)
Subject: Re: HX Seasonal adjustment
In article <46158f92$0$17258$5a62ac22@per-qv1-newsreader-
01.iinet.net.au >, yoma@yoma.net.au says...
> Espressopithecus (Java Man) wrote:
> > In article <46157BD0.5080401@yoma.net.au>, yoma@yoma.net.au says...
> >> daveb wrote:
> >>> On Apr 4, 11:34 pm, yoma <y...@yoma.net.au> wrote:
> >>>> Just wondering whether it's not uncommon to seasonally adjust the
> >>>> pressurestat on a HX machine?
> >>>>
> >>>> My faema E98 (Cimbali group) is plumbed in - and in the winter months I
> >>>> have to up the boiler pressure to 1.3+ bar, from around just under 1.2.
> >>>>
> >>> why would you need to?
> >> Under-extracted taste (as winter comes on).
> >>
> >> The water comes in via plumbing directly from outside the building. The
> >> tap water temperature from the same outlet varies considerably b/w seasons.
> >>
> >> Should a HX machine be this sensitive?
> >>
> > Do you flush the brewhead/HX before pulling your shots? The technique
> > described as "watching the water dance" should eliminate any need to
> > change the pstat setting seasonally.
> >
>
> Yes.
> And the water dance varies depending on how hot/cold the weather is.

But it allows you to stop the pump as soon as the head/HX has been
flushed of superheated water. Every make of machine is a little
different, but shouldn't you be able to judge when to shut of the flush
so that you get the machine into brewing range any time of the year? Of
course, the water dance may help in a relatively narrow range of water
inlet and indoor temperatures. Is your workshop unheated? And do your
waterlines go through unheated areas?
>
> I think this is the case with all machines - and is a measure of the
> heat loss of the group head as a well as the water coming out of the HX.
>
> Anyhow couldn't the flushing actually compound the problem? The flush
> would remove the 'overheated' water. Then fresh water coming into the
> HX could be very cold/hot.

The water coming into most HXs is considerably colder than the water
leaving -- unless you're writing to us from "the hot place" below . . .
.
>
> Maybe turning up the pressurestat compensates for general heat loss in
> the group head, which makes just as much difference?

It will make your boiler run hotter, and the water in your HX will be
hotter as a result.
>
> Of course all this may not apply, for a machine in an air-con building
> with plumbing already having run some length indoors,
>
> Thanks
> -Yoma
> Maybe this is one contributing factor from:
> - room temp.
> - boiler temp.
> - water input temp.
>
> A tanked hx machine in an air-conditioned room would lose less heat,
> it's water input would be warmer than a plumbed hx machine in a cold
> workshop.
>
If the temperature of the room in which your machine is located varies
significantly throughout the year, you may need to tweak the
pressurestat seasonally. I can't recall reading of another case like
yours, though.

Rick


      
Date: 09 Apr 2007 13:38:19
From: yoma
Subject: Re: HX Seasonal adjustment
Espressopithecus (Java Man) wrote:
> In article <46158f92$0$17258$5a62ac22@per-qv1-newsreader-
> 01.iinet.net.au>, yoma@yoma.net.au says...
>> Espressopithecus (Java Man) wrote:
>>> In article <46157BD0.5080401@yoma.net.au>, yoma@yoma.net.au says...
>>>> daveb wrote:
>>>>> On Apr 4, 11:34 pm, yoma <y...@yoma.net.au> wrote:
>>>>>> Just wondering whether it's not uncommon to seasonally adjust the
>>>>>> pressurestat on a HX machine?
>>>>>>
>>>>>> My faema E98 (Cimbali group) is plumbed in - and in the winter months I
>>>>>> have to up the boiler pressure to 1.3+ bar, from around just under 1.2.
>>>>>>
>>>>> why would you need to?
>>>> Under-extracted taste (as winter comes on).
>>>>
>>>> The water comes in via plumbing directly from outside the building. The
>>>> tap water temperature from the same outlet varies considerably b/w seasons.
>>>>
>>>> Should a HX machine be this sensitive?
>>>>
>>> Do you flush the brewhead/HX before pulling your shots? The technique
>>> described as "watching the water dance" should eliminate any need to
>>> change the pstat setting seasonally.
>>>
>> Yes.
>> And the water dance varies depending on how hot/cold the weather is.
>
> But it allows you to stop the pump as soon as the head/HX has been
> flushed of superheated water. Every make of machine is a little
> different, but shouldn't you be able to judge when to shut of the flush
> so that you get the machine into brewing range any time of the year? Of
> course, the water dance may help in a relatively narrow range of water
> inlet and indoor temperatures. Is your workshop unheated? And do your
> waterlines go through unheated areas?
>> I think this is the case with all machines - and is a measure of the
>> heat loss of the group head as a well as the water coming out of the HX.
>>
>> Anyhow couldn't the flushing actually compound the problem? The flush
>> would remove the 'overheated' water. Then fresh water coming into the
>> HX could be very cold/hot.
>
> The water coming into most HXs is considerably colder than the water
> leaving -- unless you're writing to us from "the hot place" below . . .
> .
>> Maybe turning up the pressurestat compensates for general heat loss in
>> the group head, which makes just as much difference?
>
> It will make your boiler run hotter, and the water in your HX will be
> hotter as a result.
>> Of course all this may not apply, for a machine in an air-con building
>> with plumbing already having run some length indoors,
>>
>> Thanks
>> -Yoma
>> Maybe this is one contributing factor from:
>> - room temp.
>> - boiler temp.
>> - water input temp.
>>
>> A tanked hx machine in an air-conditioned room would lose less heat,
>> it's water input would be warmer than a plumbed hx machine in a cold
>> workshop.
>>
> If the temperature of the room in which your machine is located varies
> significantly throughout the year, you may need to tweak the
> pressurestat seasonally. I can't recall reading of another case like
> yours, though.
>
> Rick