Zone Heating and Weather compensating controls .

[verdigrey]

Hi There , Could some of you experienced Guys out there give me some advice please . We have a job coming up that is a bit bigger than we normally do . We are used to installing new heating systems in 3 or 4 bedroom houses , but this is a bit bigger .
It is an old 6 bedroomed detached house . At the moment it has Oil boiler 26 kw and about 12 rads ( some rooms have electric storage heaters ) . The rads are quite old and some of them are on internal walls . A lot of the rads are undersized .
The customer would like the whole system upgrading , i.e.
New more efficient Boiler ,
New more efficient Radiators ,
Thermostatic valves fitting ,
The pipework renewing , maybe part copper and part plastic .
I would like to change it from Open Vented to a sealed system . Is it worth having the Ground floor on one Zone and the 1st and 2nd floor on another ? and what are the advantages of zoning ? Also , looking at the Domestic Heating Design guide it mentions Weather compensating controls , I dont know anything about them , have any of you installed them and was it worth it ?
Thanks Guys .

 

[unguided1]

Definately zone it also what age is the house as they will more than likely need to upgrade the insulation and airtightness on the property, As they are on oil at the moment it would definately be worth talking to them about renewables of some form, and weather compensation goes with out saying

 

[verdigrey]

Thanks Unguided1 , I dont know how old the house is , I am not a very good judge , but there are wooden shutters on the inside of some of the windows if that helps . They have had a Thermal imaging survey done to see where they are losing heat and they are going to improve the insulation . They seem to know about Renewables , They were talking about perhaps having a Wood pellet boiler instead of an Oil Boiler . I have heard that Wood pellet boilers can be troublesome if the Pellets are not good enough quality , but our job is to install the new rads etc and the Boiler is to be done at a later stage .
What is the best make of Weather compensating controls ? Cheers

 

[unguided1]

To be honest I wouldnt worry about the weather compensation if the customer has not decided on which heat source they are using, my reason for saying this is that the majority of manufacturers now supply weather compensation for their individual ranges and it would make more sence to install the manufacturers own kit than sombody elses that may struggle to be compatible.

If your customer decides to go down the pellet boiler route, suggest that they first look at the price of the fuel and also make sure that they look at a good quality fuel as well

 

[verdigrey]

Thanks Unguided , You make good points .
Re Zoneing , If the Ground floor is seperate to the first floor and have seperate programmers in an average Household would they be set to come on at different times ?

 

[unguided1]

Ultimately the bedrooms need to be cooler than living rooms the more control on the system the more efficient it should/ can be provided the customer fully understands how to use the controls for ultimate efficiency, Just remember most customers do not want to drive their system they want it all to be automatic.

Ultimatley you will be installing a minimum of three zones, one ground floor, one first floor, and one for DHW, Not knowing the building you working on, if for example there is an annex or granny flat you may want to zone this as well. Having said that you will need to discuss it with your customer as the more zoning, the more cost and ultimately your customer is paying.

 

[doitmyself]

Is it worth having the Ground floor on one Zone and the 1st and 2nd floor on another?

What is the total floor area?

If under 150m², you must have at least two zones with separate temperature control in each zone.

If over 150m² you must have at least two zones with separate time and temperature control in each zone.

and what are the advantages of zoning?

Better temperature control, which saves money.

The Domestic Heating Design guide mentions Weather compensating controls , I dont know anything about them , have any of you installed them and was it worth it?

That might start a long discussion/argument. In any case, you need a boiler which can work with weather comp controls. Read:

[DLMURL]http://www.viessmann.co.uk/etc/medialib/internet_uk/images/products.Par.84387.File.File.tmp/6pp%20Viessmann%20weather%20comp%20web.pdf[/DLMURL]

 

[verdigrey]

Thanks Unguided and doitmyself , The total floor area is over 200m 2 .
Incedentaly when the Customer had the Thermal Imaging done he said that it was surprising just how much heat was lost thru the wall behind the rads ( solid walls ) . As plumbers we know that a lot of heat is lost thru solid walls , but he was asking if we could put some kind of foil behind the rads as we went along to cut down on the loss . I have seen foiled bubble wrap , but does anyone know of anything better ?
Thanks

 

[tackleburger]

Thanks Unguided and doitmyself , The total floor area is over 200m 2 .
Incedentaly when the Customer had the Thermal Imaging done he said that it was surprising just how much heat was lost thru the wall behind the rads ( solid walls ) . As plumbers we know that a lot of heat is lost thru solid walls , but he was asking if we could put some kind of foil behind the rads as we went along to cut down on the loss . I have seen foiled bubble wrap , but does anyone know of anything better ?
Thanks

You get reflector pads for behind rads.

Regarding weather comp I can't see that working on a heat source like wood pellets. If you are multi zoning you will need a box of tricks from the manufaturers in most cases, that said the likes of ideal are open therm and you can use honeywell controls with a honeywell weather comp. When I do a job like this I usually go for Vaillant controls and use the VR61 mixer module you can get two heating zones and one hot water with weather compensation. The cylinder can be worked via the VR10 sensor probe and that way you can heat the cylinder to a comfortable temperature say 55deg and use the anti legionella function to bring it over 60deg now and again. THe VRC 430 is a great piece of kit and an RF version is available too. This makes it very efficient and creates a good argument to stick with gas.

 

[dontknowitall]

I was taught that you have to have gaps - and I've forgotten how much now!!

If double rad then smaller part of bracket outwards, if single then longer part outwards.

At least 100mm below rad (but this could have been 200mm!) and at least 100mm(?) above radiator before a shelf/window sill or whatever.

The idea is to allow the air to circulate around the radiator (cool at the bottom) and pass the radiator so warm comes out of the top to ceiling, then along to far wall then across floor to radiator again.

I was told foil and other materials behind the radiator are a pure waste of money.

Whether any of the above is correct or not I've no idea - only what I was told!

 

[capitanpugwash]

We've zoned our house and having had a baby it has worked brilliantly. One zone downstairs is on from 7am until 10pm and upstairs on from 7pm (bath time) until 7 am when we get up. Not heating the bedrooms all day when we are around makes huge savings. It would be less important if we were out from 8am until 8pm as we could have the whole house on one programmable thermostat and off for most of the day.

 

[tackleburger]

I know that if you do heating in caravans or other static homes you are meant to fit them. I agree can't see them making the world of difference. I suppose the small things add up though.

 

[tackleburger]

We've zoned our house and having had a baby it has worked brilliantly. One zone downstairs is on from 7am until 10pm and upstairs on from 7pm (bath time) until 7 am when we get up. Not heating the bedrooms all day when we are around makes huge savings. It would be less important if we were out from 8am until 8pm as we could have the whole house on one programmable thermostat and off for most of the day.

Put a programmable stat on each zone even better.

 

[Toddyplumb]

If you do go for weather comp make sure it can be bypassed for the cylinder circuit or on warm days your cylinder will be noticeably cooler

 

[capitanpugwash]

Put a programmable stat on each zone even better.

Wasn't very clear but this is exactly what we do have! Although Horstmann stuff that seems to need replacing every other year!

 

[verdigrey]

Thanks Tackleburger , I guess that we wont be able to use Vailant controls as it wont be a Gas boiler that gos in . It looks like Honeywell may be favourite .
Re Rad distance from wall , Quin catalogue shows 36mm is max , but I quess we could chock them off the wall a bit more as long as it looks presentable .
Thanks everyone else for your input . We start the job this wednesday . We will drain system , remove old rads and dismantle the old single pipe system first .

 

[tradesmen11]

Installing and Utilizing effective system controls is vital to the success of any renewable energy heating system.

-Zone Heating
-Thermostatic control
-Hot water priority
-System compensating controls
-Chronostats (where applicable)

-Weather Compensation Controls
Our homes specific heating needs, correlate to the degree of temperature difference between between indoors and outdoors, in order to replace heat lost through the walls, roof etc. The colder it is outside, the greater the heat loss and the more we have to heat the building, to compensate. Weather compensation controls work by ensuring that the heat pumps space heating output matches the heat lost from the building. The house will always maintain the desired temperature for maximum comfort, without the need for individual room thermostats. A small temperature sensor is located on the outside of the building, normally on a north facing wall, which is wired back to the heat pump relaying information about the outside temperature every few seconds. When the temperature changes outside the heat pump responds and starts to increase or decrease the heating output temperature to compensate for new rate of heat loss, and maintain the comfortable inside temperature. Therefor the increased rate of heat loss has been counteracted, before any internal temperature drop. This allows the heat pump to operate most efficiently, utilizing heat distribution when and where its required most. In essence with weather compensation we are only putting enough energy into the building at any time to replace the heat lost, resulting in an efficient and comfortable system with no over/under heating. because the system is pro-active, rather than reactive, you won't notice the subtle temperature changes. You certainly won't be feeling the cold and don't need to worry about adjusting a room thermostat.

 

[tackleburger]

If you do go for weather comp make sure it can be bypassed for the cylinder circuit or on warm days your cylinder will be noticeably cooler

By-passed?? If you fit the correct controls the boiler knows when there is a hot water demand and prioritises hot water. Never heard of by-passing unless we are talking about the same thing.

 

[Bronze_tap]

Customer had the Thermal Imaging done he said that it was surprising just how much heat was lost thru the wall behind the rads ( solid walls ) . As plumbers we know that a lot of heat is lost thru solid walls , but he was asking if we could put some kind of foil behind the rads as we went along to cut down on the loss . I have seen foiled bubble wrap , but does anyone know of anything better ?
Thanks

There is 10-15 mm thick foam with foil sold in rolls in the eastern/northern europe. Also you can just buy 20mm PU or polystyrene sheets and stick it to the wall surface on the inside by coving or tiles adhesive.
Apply thick kitechen foil on top behind the rad by the PVA glue. (if not already there). Make sure to mount the wide radiator brackets before gluing the foam/polystyrene to the wall. Also make sure, that the rad is 10-15 cm above the floor. You can use bits of wood with longer bracket screws between brackets and wall if the rad is too close to the wall/insulation. If the customers wants, you can apply it to the entire external wall with rad, and line it with paper/decorate it over. Cut the Styrofoam onto 50x50CM tiles, so there is less stress in it when the glue dries. Make sure the base adhesive layer is COMPLETELY dry before trying to apply a paper on top of Styrofoam! Wait for a few days (up to a week).

PS: I'm really surprised, nobody was mentioning it on here, looks like some folks would greatly benefit from the business/private Christmas trip to somewhere like Norway, Iceland, Alberta province in Canada or at least Germany, Poland or Russia, and exchange experience and ideas with the plumbers/CH systems maintenance folks there. It would get them properly prepped to the future UK climate surprises.
Make sure to cover the aspects of condensing boiler/outside sever pipes operations at -20 C :8: and rads sizing.
Hope the UK midlands/north guy's can understand about what I'm talking by looking onto their calendar and outside their window now...
While there is the global warming, we have an increase in climate volatility here, and it only takes 1-2 nights for typical UK house without power at -15C to get it's owner searching for new CH install quote and a toilet(s), unless you've good some solid fuel backup or generator + lots of fuel... or know how to completely drain it before your's house reaches 0 degrees ... or have used some antifreeze in the CH system.

PPS: I've heard about such behind the rads insulation on TVP1 ~25 years ago...

And I wish everyone a Happy White Easter. (if the forecast is right).

 

[tamz]

While there is the global warming

Shhhhh. That stopped years ago. They now call it climate change because it always changes. Keep taking the medicine :wink:
[video=youtube;AxM841f08VA]http://www.youtube.com/watch?v=AxM841f08VA[/video]

 

[Roger Welton]

It's global warming again at the moment as its warm outside

 

[Heating-eng]

There more Zones the better really,