Replacement heating for an Old Farmhouse

[Iceverge]

Friends of mine are living in an old farmhouse. 

 

It will need to be entirely replumbed. They have a good supply of well water. Insulation levels are poor. Stab in the dark estimation of heat loss may be 20kW. 

 

Their desire is to build a replacement house within the next 10 years but will need to live here for another 5 at least and need a low cost heating system to carry them through until then. 

 

They have 3 phase on site but the cost of an ASHP may be too much and I worry it would not have the power to heat the building. I suggested a basic oil boiler and Rads. There is no gas on site but they may be able to get LPG. 

 

 Would a second hand boiler or even oil fired cooker like an Oil Rayburn be a suggestion?

 

What layout would you use?

Pressurised DHW would be appreciated. What is the best format for this? I installed a Maxipod thermal store in my parents house and it's working very well but an UVC may be simplier?

 

 

 

 

 

 

[-rick-]

Such a high heatloss because it's a leaky place?

 

Left field option, air to air heatpumps (ie AC). Not intending to warm the structure but the air? May be the cheapest option considering no gas, cost of oil, etc.

[-rick-]

To clarify, install AC/multisplit in the main rooms. Use electric radiators/fan heaters in smaller or occasionally used rooms. Likely get this installed cheaper than the alternatives unless you can get a grant for wet heatpump setup. Scrap exisiting CH plumbing.

 

DHW just use direct tank with immersion, or as they have 3 phase, maybe 3 phase high power electric boiler/shower (less standing losses but if using time of use billing maybe higher bills).

Edited 22 hours ago by -rick-

[-rick-]

Thinking further and depending on their financial situation and attitude, if this does come in significantly cheaper than the other options (over 5+ years) then have the possibility of taking the difference and using that to build a ground mount solar array (assume farmhouse comes with some land). Position it such that it can stay after they build the new house. Summer generation will help offset some bills and it's a longer term investment that putting it directly into the property. Government support might also be available.

[Iceverge]

53 minutes ago, -rick- said:

Such a high heatloss because it's a leaky place?

 

Left field option, air to air heatpumps (ie AC). Not intending to warm the structure but the air? May be the cheapest option considering no gas, cost of oil, etc.

 

 

 

Good suggestion. However given the high heat demand I would worry about meeting the total heat demand. An electric fan heater doesn't touch the sides at the moment some of the rooms. From my own experience it works well ( immersion + A2A HP ) in a well insulated house however out peak heat demand is less than 2kW. 

 

Also would the cost of install be quite a lot more than a DIY-ish Oil system?  I think solar is in the pipeline for the farm side of things at some stage. Running costs aren't a huge consideration at the moment. Getting something up and running quickly and cheaply that will keep them going for 5 years is the aim. Small kids etc so cold water gets boring quickly.  

 

 

 

 

[JohnMo]

Or a hiaer heat pump cylinder - billy bargain price

https://www.wolseley.co.uk/product/haier-200l-heat-pump-water-heater/

[-rick-]

27 minutes ago, Iceverge said:

Good suggestion. However given the high heat demand I would worry about meeting the total heat demand. An electric fan heater doesn't touch the sides at the moment some of the rooms. From my own experience it works well ( immersion + A2A HP ) in a well insulated house however out peak heat demand is less than 2kW. 

 

Heatpumps can meet any demand you choose as long as you buy big enough.

 

https://www.aircondirect.co.uk/p/2059835/lg-dualcool-pro-a-12000-btu-smart-wall-mounted-split-air-conditioner-with-heat-pump

 

Picked the above at random, it outputs >3.5KW much more than a fan heater while consuming >3x less for equivalent output. They have one double the size for less then double the price.

 

Is this a really big property? Really leaky? What's the cause of such high heat loss? If it doesn't have loft insulation do that before anything else.

 

27 minutes ago, Iceverge said:

Also would the cost of install be quite a lot more than a DIY-ish Oil system?  I think solar is in the pipeline for the farm side of things at some stage. Running costs aren't a huge consideration at the moment. Getting something up and running quickly and cheaply that will keep them going for 5 years is the aim. Small kids etc so cold water gets boring quickly.

 

AC is very quick and easy to install as long as you don't might the outdoor units spread about (or have planning issues related to that). Mutlisplit a bit more so but still quicker and less disruptive than redoing central heating (pipes tend to run externally)

 

Never really investigated the cost of an oil system from scratch. I thought getting a tank installed generally involved planning amoung other things so assumed it's not a particularly cheap option. If it works out the cheapest option and the environmental cost is not a concern then go for it. AC heatpumps I would guess will be fairly competitive on price once you consider redoing all the plumbing, cost of new radiators, etc.

Edited 21 hours ago by -rick-

[-rick-]

10 minutes ago, JohnMo said:

Or a hiaer heat pump cylinder - billy bargain price

https://www.wolseley.co.uk/product/haier-200l-heat-pump-water-heater/

 

If the rest of the house is generally cold then a heatpump cylinder outputting cold air won't be a great help. Much better option if you have a well insulated house that has more issues with cooling than heating.

[Iceverge]

7 minutes ago, JohnMo said:

Or a hiaer heat pump cylinder - billy bargain price

https://www.wolseley.co.uk/product/haier-200l-heat-pump-water-heater/

 

Yes. That crossed my mind too. A good option for DHW but given the short window for payback maybe an immersion on TOU would be as cheap. 

 

What do you suggest for CH? 

 

I was thinking an outdoor (system?) oil boiler to an UVC or TS. A parallel two pipe CH setup with TRVs on each rad. Larger heating pipe diameters and rads to allow for lower flow temps?

 

 

Would that work? 

 

 

[JohnMo]

8 minutes ago, Iceverge said:

Yes. That crossed my mind too. A good option for DHW but given the short window for payback maybe an immersion on TOU would be as cheap. 

That's what I now do. Even with a heat pump.

 

9 minutes ago, Iceverge said:

What do you suggest for CH? 

If you go oil do a thermal store, possibly plate loaded DHW, run CH system how you want.

 

If you went lpg UVC run on priority domestic hot water setup. Then run rads at 50 degs or lower for good efficiency. 

 

If you want it simple do a combi or storage combi - no cylinder needed

 

Not sure I would run A2A unless you are only there intermittently. Then you are just heating air in the most part. So quick response heating.

2 hours ago, Iceverge said:

desire is to build a replacement house within the next 10 years

And 10 years ends up 15, and your heating system will need looking at most likely anyway.

[-rick-]

56 minutes ago, JohnMo said:

Not sure I would run A2A unless you are only there intermittently. Then you are just heating air in the most part. So quick response heating.

 

Quick response heating was what I took as the brief. If you have a 20kw heatloss then keeping the whole place warm for long periods of time is going to burn thousands of euros a year no matter how you heat the place. If you are willing to spend that sort of money, better to spend some of it reducing the heat loss.

 

With a property with 20kw heat loss your only real economical heat option is to heat the rooms you are in and not the rest. Not the most comfortable way to do it but plenty do. That needs fast response. Either high temp radiators or some form of air driven heating.

 

56 minutes ago, JohnMo said:

And 10 years ends up 15, and your heating system will need looking at most likely anyway.

 

I took this as a do minimum to the property so we can exist for 5 years, 10 pushing it. Saving money for the knockdown/rebuild. On an horizon over 5 years again IMO the balance lies in reducing the heat loss. 20kw really is an awful lot unless this place is a mansion and if it's not a mansion then there must be a number of quite quick/easy fixes to bring the loss down.

[FarmerN]

I have no idea how the economics would work out. But if only relatively short term would old fashioned night storage heaters  have a place ?

Run on Cosy or EV charging tariff.?

Log burner is great for main living space. Moved after 50 years from very large, old draughty farm house 6+ bedrooms.

We lived with Oil fired cooker , a wick burner so kept going in power cuts                       (4500 liters / year ). Log burner using 8 cu M logs a year and night storage heaters. The logs and electric were lost in the business. 

Our experience was you needed to keep the main living rooms warm, no matter how much heat  you put in, if the fabric was cold , it felt cold.

It was a healthy enviroment to bring kids up in, if a little bracing at times.

Edited 19 hours ago by FarmerN

[SteamyTea]

TL:DR

 

Get them to do a basic heat loss calculation.

And have a look at the current bills.

Without even basic data, it is hard to recommend anything really.

 

Though A2AHPs are cheap to buy, install and run.

[Nickfromwales]

5 hours ago, Iceverge said:

I was thinking an outdoor (system?) oil boiler to an UVC or TS. A parallel two pipe CH setup with TRVs on each rad. Larger heating pipe diameters and rads to allow for lower flow temps?

 

 

Would that work? 

Yup. Simple, effective, and boatloads of DHW on tap with a......

 

5 hours ago, JohnMo said:

thermal store, possibly plate loaded DHW, run CH system how you want.

Don't go p;ated, just have the instant DHW coil in there and it's deliciously simple. Gives the boiler somewhere to release its anger for the requisite full long burns that oil needs.

 

Low cost? Buy everything second hand and strap it together with pushit pipework. Use copper for the primary stuff immediately off the boiler / to the TS.

[Iceverge]

Nice. 

 

They also have UFH fitted in 2 renovated rooms I've discovered. 

 

They're beside a milking parlor that's dumping about 300kWh of heat daily through milk cooling too.

 

HOWEVER......

 

Simple wins. Oil boiler + TS + RADs + UFH. 

 

Would 15mm push fit Hep2O to  large rads + UFH work ok on one zone from the TS at say 45deg flow temp? 

 

 

 

 

 

 

 

 

 

[-rick-]

28 minutes ago, Iceverge said:

They're beside a milking parlor that's dumping about 300kWh of heat daily through milk cooling too.

 

Could be an interesting project to use that. Though guess regulations make doing anything there quite difficult.