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Sizing of heat pumps

Mars · 2021-03-05T09:48:26Z

A lot of people that are new to heat pumps have questions about whether a heat pump has been correctly sized for their home. Discuss heat pump sizing questions and issues here.

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Mars

(@editor)

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Topic starter 16/03/2021 11:07 am

@bobbt9866, that's a great tip. Very helpful.

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bobbt9866

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16/03/2021 11:36 am

@editor

This is the video I mentioned.

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Optimum Energy Solutions

(@optimum-energy-solutions)

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25/03/2021 9:24 am

A full heat loss calculation in accordance with latest version of MIS3005 and using a method that complies with BS EN 12831 with internal and external design temperatures in accordance with CIBSE guide must be employed. For anyone looking to receive incentives (RHI for example) this is not optional but mandatory and as part of the MCS handover it is a requirement that a full heat loss calc is given to the customer.

Unfortunately this is rarely done and we know this from experience having carryied out site audits for an energy company in this sector as well as training hundreds of people as part of a Government funded programme now underway.

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bobbt9866

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25/03/2021 12:01 pm

@optimum-energy-solutions

Of course a full heat loss should be done, but we are also giving novices some idea on how to size a load before deciding whether they can afford to change their heating systems.

Giving the fiasco of Green Deal 1.0 & 2.0 and the reduction in funding generally, many may not go the MCS route. Hopefully they do!

The client should have a heat loss calc before going ahead and have it explained to them in simplistic terms with queries answered.

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Optimum Energy Solutions

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25/03/2021 1:02 pm

Estimating a demand is pretty easy with an EPC if you're also a DEA and can read between the lines. In the scheme of things the size of the heat pump shouldn't make a huge difference to the price as there's just as much installation involved in fitting a small heat pump as a big one. However I wouldn't suggest a novice even contemplates sizing a system.

As the incoming incentives post March 2022 will also require regulation probably aligned to the forthcoming updated MCS regs, I see no reason why any client would choose to follow a different route to benefit from what is after all free money albeit somewhat reduced next year.

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bobbt9866

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25/03/2021 1:23 pm

@optimum-energy-solutions

Missing the point really.

No one is suggesting that a heat load calc is not required but a rule of thumb method was suggested to assist novices, of which there are many.

If someone is trying to decide whether to change or just service their boiler it is good for them to have a guide to sizing before calling in a qualified engineer.

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Optimum Energy Solutions

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25/03/2021 2:07 pm

Sorry but we will have to agree to disagree - the system size is not directly related to price which I can only surmise is what you are eluding to?

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bobbt9866

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25/03/2021 2:56 pm

@optimum-energy-solutions

Wasn't aware we were disagreeing.

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Optimum Energy Solutions

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25/03/2021 3:14 pm

I must be missing the point as you say - I just cannot possibly see how the size of a system could in anyway help someone decide whether to change from a boiler to heat pump as you mentioned?

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bobbt9866

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25/03/2021 3:21 pm

@optimum-energy-solutions

It allows people to do some research before 'wasting' an engineers time. If they can get a ball park size and get indicative prices it could help make a decision as to whether they have the budget.

If they can afford it, they then call in an engineer to do proper heat calculations and get advice as to what they can do to reduce the heat loss plus get a detailed quote.

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bobbt9866

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25/03/2021 3:24 pm

@optimum-energy-solutions

I would add that, if you rely on the media for your research, as many do, they would get a highly inflated idea on what a Heat Pump system costs, due to vested interests. They may even get frightened off making the change at all.

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Optimum Energy Solutions

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25/03/2021 4:00 pm

Sorry but I can't see how someone could possibly get an indicative price of a system simply by making a misinformed guess at the possible size of a heat pump?

They would still have to refer to an installer/s who one hopes would do more than rely on a house holders guesstimate - it's just not appropriate and potentially very misleading.

The potential size of a system cannot give any indication at all of the potential cost.

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