Going green(er) with a Viessmann 200W (& heating efficiency home improvements)

QrizB

michaels said:

QrizB said:

michaels said:

Q1. If we were to go for a bi-valent system is there a way from the heat days data to work out what proportion of total heating requirement is when temp is below 5 degrees (gas energy) as oppsed to 5 and above (heat pump).

I would guess so; get two sets of degree-day data, one at your lower temp and one at your higher one, and look at the difference. It would give you a feel for things, at least.

Wouldn't the lower temp degree days only include the degrees to get up to 5 though so I would need to add on 10 degrees times the number of days/hours which I wouldn't know.

The degree-day data is split out daily. You could go through a copy of the high-temp data, day by day, and delete the data wherre there's no entry on the low-temp data.

This will give you a table that shows the degree-days needed only for the days where the temperature was below the low temperature.

Obviously this will be an over-estimate, since having one measurement in a day below eg. 5C would mean counting the whole day as being heated by gas. But it's somewhere to start.

michaels

QrizB said:

michaels said:

QrizB said:

michaels said:

Q1. If we were to go for a bi-valent system is there a way from the heat days data to work out what proportion of total heating requirement is when temp is below 5 degrees (gas energy) as oppsed to 5 and above (heat pump).

I would guess so; get two sets of degree-day data, one at your lower temp and one at your higher one, and look at the difference. It would give you a feel for things, at least.

Wouldn't the lower temp degree days only include the degrees to get up to 5 though so I would need to add on 10 degrees times the number of days/hours which I wouldn't know.

The degree-day data is split out daily. You could go through a copy of the high-temp data, day by day, and delete the data wherre there's no entry on the low-temp data.

This will give you a table that shows the degree-days needed only for the days where the temperature was below the low temperature.

Obviously this will be an over-estimate, since having one measurement in a day below eg. 5C would mean counting the whole day as being heated by gas. But it's somewhere to start.

Thanks
10 character rule

Reed_Richards

michaels said:

Q2. Our gas boiler has weather comp, the output modulates to the level where the flow temp required to match the heat loss is maintained.  With a HP that has a fixed temp output setting is the output controlled via a room stat that switches the pump on and off as the room temp rises above or falls below the desired level?

My heat pump is controlled by a room stat that switches it off and on as the temperature rises above and falls below the desired level.  This applies whether I operate it with a fixed temperature output setting or using Weather Compensation.  All that changes between the two modes is the frequency of off/on transitions.  

The gas boiler describes sounds as if it has Load Compensation as well as Weather Compensation.  This can modulate the boiler to maintain whatever temperature is set on the room thermostat but requires that the boiler can read the room temperature and the room thermostat setting.    

Screwdriva

Final flooring and tank insulation complete. Episode coming soon! 

gefnew

Looks like very cheap pipe lagging also it is installed wrong way round ,go back and get them to try to get it right.

Screwdriva

gefnew said:

Looks like very cheap pipe lagging also it is installed wrong way round ,go back and get them to try to get it right.

1) Isn't cheap
2) Installed correctly. Converted to a 4 pipe system. 

Reed_Richards

Screwdriva said:

gefnew said:

Looks like very cheap pipe lagging also it is installed wrong way round ,go back and get them to try to get it right.

1) Isn't cheap
2) Installed correctly. Converted to a 4 pipe system. 

There is more expensive pipe lagging available, potentially thicker and/or with a foil cover.

Screwdriva

I'm aware. We looked at the foil insulation and decided it was overkill.  That said, the insulation used wasn't cheap as suggested. 

Reed_Richards

I have used foil-coated insulation in my loft where any heat lost from pipes is wasted.  All joints are sealed with aluminium tape so it takes a very long time to fit to straight lengths of pipe.  Bends or joints are so troublesome that I used flexible insulation there.  It's definitely a DIY job; paying someone to do it would be prohibitively expensive.

Meatballs

Recently did milled in UFH, thinking it would be less hassle than the polypipe approach, fairly pleased with result. However with the dust created (they use a vac etc but fine dust still gets everywhere), and still needing to redo skirting for tiling and resiting of WC elements then I think I would go polypipe route if I was doing it again.

Will have Octopus out to survey and quote for HP to replace our 1999 non condensing boiler...