How to live without heating - save £000s

Rosa_Damascena

Can we just remember that as expensive as heating is, whilst no one is advocating being wasteful neither is there virtue in not using the facility when it is there. I am reminded of the 87yo lady who died of hypothermia as she was terrified of the her heating bills.

I personally am not looking forward to the imminent drop in temperature but plan to keep warm through exercise, clothing AND central haeting.

masonic

Absolutely, I don't think anyone is suggesting people risk their health to save money on heating. There are some groups who should not consider this at all. It's more a case of testing assumptions about what would be comfortable within the limits of safety for the individual.

Spies

How do people prevent mould growth at temperatures like 12c?

I ran my dehumidifier this afternoon which brought indoor humidity down from 80% to 70% but then when it's switched off it creeps back up, currently sat at 77% again which is too high and this is at 19c

QrizB

Spies said:

How do people prevent mould growth at temperatures like 12c?

I ran my dehumidifier this afternoon which brought indoor humidity down from 80% to 70% but then when it's switched off it creeps back up, currently sat at 77% again which is too high and this is at 19c

Not sure what the wether was like today in your region, but here it was bright and dry. Excessive indoor humidity would suggest insufficient ventilation.

Spies

QrizB said:

Spies said:

How do people prevent mould growth at temperatures like 12c?

I ran my dehumidifier this afternoon which brought indoor humidity down from 80% to 70% but then when it's switched off it creeps back up, currently sat at 77% again which is too high and this is at 19c

Not sure what the wether was like today in your region, but here it was bright and dry. Excessive indoor humidity would suggest insufficient ventilation.

It's 80+% RH outside, I think my windows are a bit draughty 

masonic

Spies said:

How do people prevent mould growth at temperatures like 12c?

I ran my dehumidifier this afternoon which brought indoor humidity down from 80% to 70% but then when it's switched off it creeps back up, currently sat at 77% again which is too high and this is at 19c

We've had some really warm humid weather recently, which does pose quite a challenge to avoiding damp-related problems. This isn't much of a problem when there is a temperature differential outside, since warmer air holds a lot more moisture, so the RH of outdoor air drops significantly when brought up to room temperature.

That said, if you're experiencing RH of 80% at 19 °C with the use of a dehumidifier, that does rather suggest a pre-existing damp problem.

QrizB

Spies said:

QrizB said:

Spies said:

How do people prevent mould growth at temperatures like 12c?

I ran my dehumidifier this afternoon which brought indoor humidity down from 80% to 70% but then when it's switched off it creeps back up, currently sat at 77% again which is too high and this is at 19c

Not sure what the wether was like today in your region, but here it was bright and dry. Excessive indoor humidity would suggest insufficient ventilation.

It's 80+% RH outside, I think my windows are a bit draughty 

Is it 80% RH and 19C outside?

If its 80% RH and (say) 10C outside, ventilation will reduce the indoor RH.

Are you OK with the idea of absolute humidity, rather than relative? If not, that statement might sound crazy.

At 19C, the saturated vapour pressure of water is about 2.2kPa. When we say it's 19C and 80% RH, we mean the vapour pressure of water in the air is 80% of 2.2kPa, which is 1.76kPa.

At 10C, the saturated vapour pressure of water is lower; it's about 1.2kPa. So, if it's 10C and 80% RH, the vapour pressure of water in the air is 0.96kPa.

Imagine you replaced all the air in your room with outdoor air, at 10c and 80% RH. The air will bring that 0.96kPa of water vapour with it. Then it will warm up to 19C from contact with your walls, furniture, etc.

At least to begin with, it will still only contain 0.96kPa of water vapour.

At 19C, 0.96kPa of water vapour is only (0.96/2.2=) 44% RH. So the RH in your room will fall if you increase ventilation.

(I've grabbed all these numbers from a set of online steam tables, as I don't have my work references at home.)

Edit ti add: @masonic replied while I still had my nose in the steam tables!

Spies

Yeah I understand relative humidity 

It's 14c at 83% humidty outside right now, best case inside would be 62% if the room was sealed and outdoor air was heated to 19c

Spies

masonic said:

Spies said:

How do people prevent mould growth at temperatures like 12c?

I ran my dehumidifier this afternoon which brought indoor humidity down from 80% to 70% but then when it's switched off it creeps back up, currently sat at 77% again which is too high and this is at 19c

That said, if you're experiencing RH of 80% at 19 °C with the use of a dehumidifier, that does rather suggest a pre-existing damp problem.

The 20L dehumidifier does remove the moisture and bring the RH down, it's just went it's turned off it creeps back up again

HertsLad

I have a dehumidifier which collected bucket loads of water from the room where I used it, until I turned off mains electricity a couple of years ago. Now, I don't think I have enough solar power to justify using it. As I have said before, I don't see any sign of mould in my house. I guess it's a problem in properties or rooms which are heated, when moist air hits warm surfaces. I regard it as another advantage of not heating my house.