Tetrarch

Locating ASHP near oil tank

Recommended Posts

I'm looking at a multi-source approach to heating combining Oil and an ASHP. Downstairs will be ~90 sq m and currently the plan is for an engineered oak floor. There will be more questions regarding insulation in the future, but the current consideration is a siting one.

 

The new extension will require resiting and replacing the current oil tank. I am very tempted to locate my new (yet to be chosen) ASHP away from the house for noise mitigation reasons. I understand that there will be a cost/efficiency from an insulated pipe run,, but is there a reason NOT to locate the ASHP on the same (new) concrete slab as the new oil tank and hidden by some screening (open to the back)?

 

Regards

 

Tet

Share this post


Link to post
Share on other sites

Why multi heat source ..? Do you currently have an oil boiler ..??

Share this post


Link to post
Share on other sites

@Tetrarch have you heard a modern ASHP? Mine is against the side of our house and is very difficult to hear, it is certainly not “noisy”. I did plan to build a vented timber cover to absorb any noise if it proved intrusive but it’s not required at all.

Share this post


Link to post
Share on other sites
4 hours ago, joe90 said:

@Tetrarch have you heard a modern ASHP? Mine is against the side of our house and is very difficult to hear, it is certainly not “noisy”. I did plan to build a vented timber cover to absorb any noise if it proved intrusive but it’s not required at all.

 

I was only going by the 25-50 dB estimates. Not a lot of noise, but not none. We currently have a hot tub that is about that volume, so we are aware of how it may irritate neighbours, especially in the countryside where our new house is located.

 

 

4 hours ago, PeterW said:

Why multi heat source ..? Do you currently have an oil boiler ..??

 

We do have an oil boiler but that will need replacing in fairly short order with something. The RHI would make an ASHP a no-brainer, especially for downstairs UFH, but we'd like to keep upstairs rads small and hot water more "on tap" - therefore an oil-combi would seem to be the most cost-effective solution on a 20-year payback basis.

 

We arre absolutely not wedded to this and would welcome any feedback

 

Regards

 

Tet 

Share this post


Link to post
Share on other sites

You shouldn't need a back up boiler - when installed in the past they were only meant for taking over from the ASHP when temperatures drop too low. This is not really a problem now, although the efficiency does drop significantly.

 

It sounds like you want a part fossil fuel and heat pump system.This means you will have reduced RHI payments as only the heat pump heating/DHW is eligible. You would need to submit meter readings as it can't be based on the EPC/heat loss calculation.  

 

If you are worried about only heating water when needed, the HWCs are highly insulated so only lose a few degrees each day and you can spec even thicker insulation. It is quite efficient for an ASHP to heat a tank up as it doesn't need to cycle on and off, which can happen with space heating.

 

I know oil prices are very very low right now, but when I calculated pre-Covid, the heat pump was considerably cheaper to heat water than fuel oil. Presumably over the next few years when aviation restarts, we'll see fuel oil return to a high price.

 

I would use the money you would have spent on an oil boiler and do extra insulation or solar PV to offset electricity consumption. 

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the reply George.

 

I didn't know about the reduced RHI payments. I will certainly have to take that into account.

 

I was thinking a Megaflo for the HWC and these are super insulated. If the HWC is not an issue, then another major issue is the size of radiators needed upstairs. From the research I've done thus far it seems that I would need rads almost double the size of normal and that would compromise some of the plans that I had in mind.

 

Regards

 

Tet

 

 

Share this post


Link to post
Share on other sites

It'd be worth talking it through with a system designer, as it depends a lot on the target temperature. So long as a room doesn't lose more energy than you put in, any size rad can heat a room - just needs to start a few hours earlier. If you could have a 2 zone system, with the upstairs running with a lower target temperature on it's own thermostat, so the smaller rads would be less of a problem.

 

Depends what you have now, really. I installed a whole new system and some of the rads are pretty big, but no wider than the windows. They're just double depth. But if you don't need fancy rads, you can get virtually any size you want.

Edited by George

Share this post


Link to post
Share on other sites
6 hours ago, George said:

It'd be worth talking it through with a system designer, as it depends a lot on the target temperature. So long as a room doesn't lose more energy than you put in, any size rad can heat a room - just needs to start a few hours earlier. If you could have a 2 zone system, with the upstairs running with a lower target temperature on it's own thermostat, so the smaller rads would be less of a problem.

 

Depends what you have now, really. I installed a whole new system and some of the rads are pretty big, but no wider than the windows. They're just double depth. But if you don't need fancy rads, you can get virtually any size you want.

 

How do I find a "system designer" ?

 

Regards

 

Tet

Share this post


Link to post
Share on other sites

If you don’t want large radiators why not UFH upstairs in a biscuit mix within a wooden floor like @ProDave.

Share this post


Link to post
Share on other sites

Mrs Tet will not countenance anything else but carpet and rads upstairs

 

Regards

 

Tet

  • Sad 1

Share this post


Link to post
Share on other sites
4 minutes ago, joe90 said:

If you don’t want large radiators why not UFH upstairs in a biscuit mix within a wooden floor like @ProDave.

At our last house we had upstairs and downstairs UFH in biscuit mix both on suspended floors.  Downstairs was tile or wood floors, upstairs was carpeted.

 

The floors need to be specified for the extra dead load of the biscuit mix.

 

At the present house we have downstairs timber floor UFH using biscuit mix and the small amount of upstairs UFH just in the bathrooms, uses spreader plates.

Share this post


Link to post
Share on other sites

I would keep the ASHP approx 1.8m away from the oil tank, keeps Oftec happy and keeps good airflow around heat pump

 

inwoukd rather pay for longer runs and have the heat pump further from the house

Share this post


Link to post
Share on other sites
2 hours ago, Tetrarch said:

 

How do I find a "system designer" ?

 

Regards

 

Tet


Depends what you are looking for and how much you are prepared to pay. Is this a new build ..?? search for M&E Consultant or M&E contractor and you should be able to find one. 
 

 

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now