House is cold - why? (split off from other thread)

[LL]

Hi - I am in a similar situation. 8 year old townhouse built by a well known house builder but not without its problems with corner cutting that I am discovering as second owner. Our house is freezing despite large radiators that should be sufficient and having them balanced. There is a lot of heat output but it is being lost somewhere.

Could someone suggest a way to check the downstairs outside facing wall's insulation? Could I cut a small hole in the wall from the inside and check somehow? If so, what would I be looking for?

I am considering adding insulating wallpaper to the outside facing walls (Erfurt Thermal Liner brand used at my parents works well) but it is rather expensive

Many thanks for your advice in advance

Laurent

 

[dilalio]

You could get a company round with thermal imaging equipment to get an idea of where you are losing heat! Try a Google to see if this service exists... Must be something like it. Think I'll look myself, out of interest!

 

[dilalio]

Here you go...
https://www.google.co.uk/search?q=home+heat+loss+inspection&ie=UTF-8&oe=UTF-8&hl=en-gb&client=safari

 

[JohnD]

We don't know how much heat you put into your house, or how big it is, or how cold it is.

Assuming you heat it with gas, how many cubic metres of gas (from the meter readings, not an estimated bill) did you use over the winter quarter?

How many hours a day do you run the heating?

What is the target temperature on your room stat, and what temperature did the rooms actually reach?

You can get a notional estimate of the amount of heat you "should" need to put into your house using this calculator:
http://calculators.baxiknowhow.co.uk/boiler-sizing/

It is very common for housebuilders to fit undersized radiators to save money. Give us examples of room sizes and radiator measurements. Are they doubles or singles?

BTW
Your loft probably (should) have about 250mm of insulation, and your walls about 60mm insulation. The fancy wallpaper you mention is about 2mm thick and will have no significant effect, except in its cost.

 

[jeff the gasman]

My brother in law had the same issue with a Redrow home. I investigated and there was no insulation anywhere , it was worse than a 1960s build.
I blame lax building control a penny pinchers.
The house was almost completely rebuilt.

 

[LL]

Hi sorry for late reply as I was away and didn't get a notification of response for some reason via e-mail. Thank you to everyone for your helpful reponses

@JohnD:

We live in a 3 storey townhouse. Temperature differential is at least 5 degrees from ground floor to top floor and more than that in ground floor back room.

We have a gas boiler heating system 1 year old Viessmann. Example usage is: Jan 237kWh, Feb 231 kWh, Mar 215, Apr 232 (forecast). Hive thermostat on ground floor. We set it to around 21 degrees as otherwise upstairs is unbearably hot with heat rising. Upstairs insulation seems good, loft insulation is good. Downstairs (even with balanced radiators by good plumber) the radiators are very hot pumping out heat but it feels cold in the rooms - even if I close the door to back room to keep the heat in. This is why I'm wondering if the walls are properly insulated. All houses on this street built at same time have this problem - you could be in a tshirt upstairs and need a coat on downstairs!

I may try a small pilot hole to see if I can see insulation and follow-up with a thermal imaging inspection if not too expensive

Re: the wallrock thermal liner there's two versions 3.2mm and 4mm thick. I used it in my parent's house when they had damp problems and it was significantly warmer after lining the external walls using it. They have a much older house though which is poorly insulated relatively.


Thanks all!

L

 

[JohnD]

what were the actual meter readings?

what size are the radiators and the rooms?

What temperature did the downstairs rooms reach?

Do you have TRVs?

Are you in Penzance or Aberdeen?

 

[Agile]

If its too hot upstairs then why not lower the setting of the TRVs rather than just complaining as if its outside your control?

Tony

 

[LL]

Hi JohnD thanks for quick response

So these are my energy company submitted readings

When Who Reading Usage
04 Apr 2016 We estimated 11774 299kWh
03 Apr 2016 You gave 11747 1982kWh
28 Feb 2016 You gave 11568 1827kWh
28 Jan 2016 You gave 11403 1661kWh
30 Dec 2015 You gave 11253 1395kWh
29 Nov 2015 You gave 11127 1052kWh

Attached is the floorplan from our house. To give a sense of scale the ground floor room marked lounge is approx 2.2m x 5m. It has a 1.2m x 0.6m single radiator and a 0.4 x 0.5m single radiator that get hot.

All rads in the house have TRVs. They are relatively low setting upstairs

Not sure of temperature would have to measure it but to give an example, I am warm upstairs and it was very cold in that 'lounge' room just now, unpleasantly so.

Based in Hertfordshire

Many thanks

 

[Agile]

The energy consumptions is of little relevance.

Its the size of rooms and the rad heat outputs that matter.

Tony

 

[JohnD]

So,
January usage was (11403-11253) = 150 cubic metres
February usage was (11568-11403) = 165 cubic metres

I also have a 3-storey house (not a town house so more external walls, and 1980's built so insulation may be poorer), heated during the day, and my usage was
January 215 cubic metres
February 187 cubic metres
So IMO your readings are very reasonable and nothing to complain about.

Your radiators are too small, which is why the downstairs rooms are cold.

My lounge is 4.5m x 6m and has two 2m doubles, though the TRVs throttle them down as soon as the room is up to temp. I used to be away on business a lot, so the radiators (and boiler) are sized to heat it quickly from cold, though that is less necessary with a modern programmable stat.

If you have any draughts downstairs, cold air will enter to replace the warm air that rises upstairs.

If the upstairs rooms are too hot, turn down the TRVs.

 

[LL]

Thanks John that is really helpful - appreciate your time to respond and give comparisons from your own experience

Tony - thanks for your feedback but John's comments are relatively far more constructive

I have just looked at the B&Q website which gives a useful BTU calculator to give me a further frame of reference (suggested at least 5569 BTU), so I will look at getting a plumber in to fit a larger double rad instead of the large single at least, will check the insulation and likely will try adding the special wallpaper to the external facing wall when we redecorate later this year. Hopefully a combination of these will get the room warmer and more tolerable!

Best regards
L

 

[Doggit]

Having lived in a 3 storey town house, I know some of your problems. The heating system has been designed on a standard basis, ie, heat required for each room, but no account has been taken for the fact that heat rises. You've already turned the TRVs down as you go up each floor, but as old TRVs are wax based, they don't react as quick as the new water based types. I suspect you don't have any wall insulation, but you can check by drilling a 25mm hole in the wall, and see if anything comes out. You also need to take in to account the orientation of the house, as north walls are always colder than south facing ones, and I suspect the back faces north from your description.

I suspect you've also got a concrete ground floor, even if it's got parquet on it.

How are the rads working, are they hot all over, or hot at the top, and cold at the bottom - does the heating system need cleaning out by any chance.

 

[LL]

Thanks Doggit that makes sense. When you say 'old' TRVs being wax based are water based ones very recent e.g. last few years? The house is 8 years old. How can I tell which I have?

We are thinking of changing the floor later this year as it is damaged, so I will be able to find out if there's concrete under there

The rads are hot all over. We had some air in system but sorted that out and now all good. Had the system checked but it is (reportedly) pretty clean and we have a magnaclean which doesn't remove that much.

 

[Doggit]

Water based TRVs are only a couple of years old, so you definitely won't have them. Once you've lifted the flooring on the ground floor, and put some fibreboards down first, things will improve a bit. As you have good experience of the Erfurt, then use that, or something similar, as I suspect it'll be easier than using celotex to insulate, but try checking with you're energy supplier to see if you qualify for wall insulation.

But you're also going to need to be realistic, as this is result of being in a townhouse - heat rises, and even if you insulate under the floorboards, and close all the door, you're always going to have this problem. There's a lot of online heat calculators which will then let you calculate the size of the rads on the ground floor once you've made your improvements, but you may then find things are worse on the top floor.