Advice on cost-effective energy saving in older houses

[Tadpole]

I hope this is in the right forum - feel free to relocate.

 

As we proceed - with help from BH - on our custom build, approaching Passiv, home, I have been asked by several friends and family what cost-effective changes they could make to their existing home to reduce its energy consumption. They typically live in houses built in the 1960's to 1990's.

 

There's plenty of talk in the media about ASHP and grants / rebates. There's also plenty of talk on here that says that's a waste of time unless you have an insulated slab. The house we're leaving as an example was built in 1997. It had air-filled, very draughty cavities and 100mm of glass fibre in the loft. Both of those were easy to retrofix.

 

So my $64,000 question is - based on the huge collective knowledge here - what would you do first, and second and third?

 

thanks 

[nod]

Adding insulation to the loft and walls is probably the most cost  effective 

Even on a well insulated home 

ASHP won’t be cheaper to run than gas 

Ideally you do need a well insulated house with UFH for a Heat Pump to be economical 

 

A friend of mine works for a company fits ASHP on a daily basis 

and says the about 95% of instructions are at 0 cost to the customer 

But still gets complaints that they are slow to hear the home and expensive 

 

I asked if he would fit one in his 

and he replied No not without UFH 

[ProDave]

2 minutes ago, nod said:

A friend of mine works for a company fits ASHP on a daily basis 

and says the about 95% of instructions are at 0 cost to the customer 

But still gets complaints that they are slow to hear the home and expensive 

 

I asked if he would fit one in his 

and he replied No not without UFH 

Good summary.

 

Even in perfect conditions, a heat pump is not going to be cheaper to run than a gas boiler.  BUT that may change of gas carries on rising faster than electricity.

 

Heat pumps work better with lower temperature water than a gas boiler so you really need UFH (AND the floor insulation needed to fit that) or over sized radiators.  And you need a larger hot water cylinder as the hot water is not the scalding hot you get from a gas boiler.

 

For many older houses, it is going to be upgrading the floor insulation that is going to be expensive and messy, particularly houses with uninsulated solid concrete floors.

[Marvin]

AIM (Airtightness, Insulation and MVHR - mechanical ventilation with heat recovery)

 

Before going APE (Airsource heat pump, Photovoltaics and Electric vehicle.  

IMHO, AIM Before APE if you have to choose.

 

Good luck

 

M 

[JohnMo]

LED lights everywhere.

 

Insulate piping.

 

Drafts, find and fix.  They will need to keep window trickle vents unless going air tight.  Look to replace standard vent fans for dMEV (run all the time at low rate), if going airtight MVHR.

 

Roof insulation, as much as practical, without blocking roof ventilation.

 

All the above can done without taking house apart.  Below needs to start taking house apart.

 

Boilers older than about 15 years old, replace, install weather compensation boiler, consider installing larger radiators and run boiler at low temp, similar to ASHP.

 

Insulated exterior doors.

 

Exterior wall insulation, cavity, interior wall insulation as appropriate.

 

Single glazing, replace with high performance double/ triple glazing.

 

Older double glazing replace with high performance double/triple glazing, u value of 1.2 to 1.4 for double, 0.8 for triple.

 

That should give them plenty to do.

[Marvin]

12 minutes ago, nod said:

But still gets complaints that they are slow to heat the home and expensive 

THEY ARE slow to heat the house. An ASHP is not a gas boiler!  The theory is that the house will have all the AIM elements and cool down slowly and that the ASHP will produce just a little heat all or most of the time to prop the temperature up. Ours is running at 35.4C at the moment and the house is 22.3C

 

The most efficient way to run an ASHP is to keep the output temperature as close to the outside temperature as possible. 

 

Like a car: Which uses more fuel going down the motorway at a steady 55 or racing as fast as you can to get where you want to go. Same result but more fuel used. 

 

With an ASHP heat slow.

 

M  

 

 

[SteamyTea]

First look at what cars they drive, and how far they drive them.

More energy, and cash, to be saved there than most people's houses.

After that, loft insulation, and all electrical appliances. A cheap plug in energy monitor is well worth it.

[nod]

1 hour ago, Marvin said:

THEY ARE slow to heat the house. An ASHP is not a gas boiler!  The theory is that the house will have all the AIM elements and cool down slowly and that the ASHP will produce just a little heat all or most of the time to prop the temperature up. Ours is running at 35.4C at the moment and the house is 22.3C

 

The most efficient way to run an ASHP is to keep the output temperature as close to the outside temperature as possible. 

 

Like a car: Which uses more fuel going down the motorway at a steady 55 or racing as fast as you can to get where you want to go. Same result but more fuel used. 

 

With an ASHP heat slow.

 

M  

 

 

Perfect for UFH 

[SteamyTea]

1 hour ago, Marvin said:

Like a car: Which uses more fuel going down the motorway at a steady 55

That fast. Maniac

 

 

[nod]

1 hour ago, ProDave said:

Good summary.

 

Even in perfect conditions, a heat pump is not going to be cheaper to run than a gas boiler.  BUT that may change of gas carries on rising faster than electricity.

 

Heat pumps work better with lower temperature water than a gas boiler so you really need UFH (AND the floor insulation needed to fit that) or over sized radiators.  And you need a larger hot water cylinder as the hot water is not the scalding hot you get from a gas boiler.

 

For many older houses, it is going to be upgrading the floor insulation that is going to be expensive and messy, particularly houses with uninsulated solid concrete floors.

I did ask the question on our first build 

and Daves advise was if you have gas nearby it will be cheaper than ASH 

Good advise 

We will install ASHP on our next two 

The problem I have Is The government  and sellers telling those who are now looking at ASHP that by replacing there gas boiler They will save money 

Even if all of us with our newly built well insulated homes could break even 

an older home hasn’t a chance 

 

Whilst we are on a gas boiler here 

and our house is twice the size of our previous home It’s cheaper to heat 

Which is all down to the amount of insulation 

Had we gone the TF route It would have been even cheaper to heat 

You simply can’t under estimate how important good insulation is 

Even something so cheap to install as a insulated loft hatch can make a significant difference 

 

While I don’t agree with the insulate Britain tactics 

They are correct in what they are saying 

[Big Jimbo]

Insulation, Air tightness, and controlled ventilation. The way we should build houses.