Overnight Heat Loss

GreeBo

I spent 6 months in an A3 rated, heat pump house and the temp would drop 5-8 degrees overnight (the setup was complicated and someone had accidentally set one of the timers to "all-day" rather than "constant" so the HP turned itself off at night)

We would be woken up by the cold in the middle of the night, temps of 12 - 14C in the bedrooms.

House was perfectly warm and comfortable as long as the HP was on.

Since BER is calculated based on materials and not the actual result its not the most useful.

KAMG

https://www.boards.ie/discussion/comment/120394939#Comment_120394939

With respect to you too, I was only giving the OP my figures, as I believe there is something wrong with his house and I want him/her to get it sorted. I went to the bother of doing it. My utility is off the kitchen and door is nearly always open between them. Temp is same in both rooms in my view. Walk in wardrobe is off our bedroom. Door is always open between them. Temp is same in both rooms in my view. And in all bedrooms. We have a weather thing in hallway that measures heat, pressure and humidity. This is constantly at 20 degrees.

There is no way a modern A2 house should lose 4 degrees in temp overnight with heat off. That's all I'm saying. Its up to him/her to get it sorted.

The Air Pump would be kicking in far too much overnight to keep the temp up. Costing a fortune in electricity.

OP, if you don't mind me asking. What is your annual electricity cost? Mine was €1,800 to €2,000 for years but obviously has increased a good bit recently.

BoardsMember

Is heating type one of the more significant variables for the temp drop overnight? e.g. ufh will give out heat long after the heating is turned off compared to rads. So side by side, you would expect less heat loss overnight with ufh versus rads. What heating system does the op have? What heating system do posters with 1 degree heat loss have?

gandalfio

Air to water heat pump with rads, no ufh. No bill yet.

DownByTheGarden

Just to give you something to compare to thats current.

Last night to this morning we lost 1C in all the bedrooms and the living room. 1.5C in the kitchen. Our house is B2 and there are normal wall vents in every room. Its in Dublin. Gas heating that was turned off at 9pm last night and still hasnt gone on yet today.

lmk123

I have an A3 rated house, very big open plan kitchen / living room, at worst the temperature dropped 3 degrees during the freezing weather but typically only drops .5, the heating rarely kicks in now that the weather is milder, heat pump, UFH, 110mm cavity insulation, 5 inch kingspan between rafters / collars and 37mm insulated slabs to the ceilings, your heat loss seems very excessive, get a survey done to eliminate the guess work, for your own sake I hope you still owe the builder money or else you can forget it

Yellow_Fern

OP, go to the attic and peruse around the gables. Look under the insulation. If you is a concrete block house, do you see the tops of the plasterboards and a avoid between them and the block gable?

cute geoge

For comparison I live in a 1940's concrete built house with 50mm insulated slab in a drafty house .Oil switched on in the evening for 4/5 hours .Usual temp is 19 degrees drops to 13 overnight normally ,14/15degrees the last few nights and as low as 10 degrees in the snow and bad frost

gandalfio

Update. So last night was 0 degress outside overnight.

Temperature in living room at 10.30pm was 21.1 degrees. Turned the stat down to 10 degrees before going to bed to test heat loss overnight.

At 8am this morning it was 15.6. A loss of 5.5 degress (similar to the figures of heat loss on nights where its 6 to 8 degrees outside).

There was little to no wind overnight.

Is it possible for that amount of heat loss through the wall vent on a night with no wind?

Havenowt

Have you tried turning off the mechanical ventilation system before going to bed to see if this is contributing to the drop of temperature.