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About this blog

This is a short blog about the thinking process, installation and results of a combined ASHP, MVHR, PV, EV charging and Water heating coil system being installed in a bungalow with good insulation and air tightness.

 

Be warned! The theory, installation and results assumed may not be right and I will only be sure when the job is completed.

 

Should you have any questions about this PM me and I will try to include an answer in the blog.

 

Good luck with your home

 

Marvin

Entries in this blog

MDi Airwall

Having had no response about the Ridgeblade product, I am now looking towards the MDi Airwall as a form of power storage.   This uses excess energy to compress air and use the compressed air to produce electricity.   The basic unit indicates a 7kwh storage capacity.         

Working on reducing mains power by best use of PV (without batteries).

Having now had a 5.12kW system running for about 6 months, usage seems to be forming a pattern. It appears we are buying an average of about 11kW a day so 28p times 11 times 365 days means a bill of about £1,200 including vat and daily charge etc (This includes charging the EV but see below). We are trying to improve this without becoming anal about it.   When you consider that our PV system realistically reaches, about 5kW max (due to orientation and roof angle) and about 1kW on a goo

Combo

Running all 4 in the winter is quite interesting:   PV generation: About a week with overcast skies and then a couple of days of sun.   January is supposed to be the low point for PV generation. Based on the EU calculator we should produce about 180kWh in January. We measured 195 which is about 6.3kWh a day on average. However generation happened spasmodically along with the weather.  For example 14kWh on a good day and 0.86kWh on a poor day.   EV Having t

Marvin

Marvin

MVHR controls

This is what my system controls would look like if I didn't have a computerised home automation system:       Wait a minute,  I haven't got a computerised home automation system!          

Marvin

Marvin

Fitting and running an ASHP

Since January 5th we have used 222kWh on the ASHP over the last 26 days. That's about 9kWh per day for heating and hot water. However some days the hot water temperature has been boosted by the PV excess power going into the immersion heater so let's assume 8kWh per day for 100m2 home. The heating is running 24 hours a day at an average of 20C. The outside temperature has been low (I will look up the records later) with only about 4 nights of frost.   Results from trying different

Marvin

Marvin

ASHP Performance

There have been lots of discussions about the effectiveness and efficiency of an ASHP and so I am keeping basic records. I have my own electric meter on the supply to the ASHP so I know how much power has been used whether from the mains or the PV.   The result so far using the ASHP installed is 123 kWhs have been supplied to the ASHP from Jan 1 to Jan the 21st to heat the building and hot water. As it is difficult to split the power used for hot water (and we have an immersion using t

Marvin

Marvin

Combo controls

Well the combo is coming together and my wife insists that I make the controls as clear as possible "in case your not here". I wondering what she means.      Still a lot to do though.. 

Marvin

Marvin

ASHP system tweaking

@Iceverge  recently pointed to@TerryE 's blog "Heating the Slab- an overview" which made me think.   TerryE has a concrete floor that he is using as a giant heat sump, heating up overnight with the warmth slowly emitting from the floor during the day. Such a simple design when the maths is right!    @SteamyTea pointed to a report about boilers and ASHP's which had various recommendations.   Having installed an electric meter for the ASHP the effect of changes can be

Marvin

Marvin

MVHR Installation 3

Well the ducting is all buried under a foot of insulation in the loft.   The coil boxes have also been covered more since the photo.   Noted the temperatures of the incoming air at the inlets in the ceilings against the outside temperature. Inside 20C ish, outside 7.8C, incoming air 20C ish.  By my calculations this seemed to good to be true and I realised, eventually, that the air was being warmed up as it passed along the ducts inside the thermal envelope of the

Marvin

Marvin

Heating a building using an ASHP

We don't have a big information system on our ASHP.  I decided just to add electric meters as a way of seeing what is going on. Our home is just about 100m2 floor plan bungalow.    Decided to run the water coils in the MVHR ducts just to draw out any air.  Left them on by mistake until we realised we were too hot but all the radiators were off!  After this I fiddled with the ASHP heating temperature. Decided to set the ASHP heating water temp to 31C last evening for the hell of it. Las

Marvin

Marvin

ASHP on a flat roof

Not really having much information to go on when installing an ASHP on my flat roof, we decided to go ahead anyway.    Questions that arose were about things like will it blow over, can the warm roof take the weight, can the warm roof take all the vibration,  will it wear away the EDPM, is the condensation OK to go into the soakaway, is there much maintenance required, how heavy is the ASHP,  can we get it up there, can we get the power up there, will the control cables reach where we

Marvin

Marvin

Water coil installation into MVHR

This is posted during the design and installation phase during the winter 2021/2022.  The cooling side results are not expected to be known until Summer 2022.   As the air passes through the water coil it changes temperature depending on the coil water temperature. If the coil is going to be used for heating only it can be used without a condensate trap. However as this is going to be used for cooling as well I have constructed a drain in the bottom.   Coil with lid off. Air

Marvin

Marvin

Loft insulation

The existing loft insulation irritated the .... out of me. Mainly because I needed to change a lot of pipes in the loft and the roof is only 22.5 degrees and the fluffy was very thick.  What with the 150mm insulated MVHR pipes (190mm thick) 2 high and a roof at 1300 ish it was too cramped. Anyone looking at the ducting photos will see the loft was bare. Before insulating, the bungalow was loosing 87% of the heat through the roof because the rest is so well insulated. Gonna have to tur

Marvin

Marvin

Loft insulation

The existing loft insulation irritated the .... out of me. Mainly because I needed to change a lot of pipes in the loft and the roof is only 22.5 degrees and the fluffy was very thick.  What with the 150mm insulated MVHR pipes (190mm thick) 2 high and a roof at 1300 ish it was too cramped. Anyone looking at the ducting photos will see the loft was bare. Before insulating, the bungalow was loosing 87% of the heat through the roof because the rest is so well insulated. Gonna have to tur

Marvin

Marvin

MVHR Installation 2

More of the same...   When insulating the ducts I noticed that the top of the MVHR was not insulated so I have installed flexi conduit on the cables ready to throw fluffy over the top.       This is the inlet pipe running under the ridge. 150 diameter with insulation held on with cable ties     An installed air damper in red. More about these later....     Water coil with thermal lid. Lid made from PIR.    

Marvin

Marvin

ASHP installation info

The viewpoint used to decide items is a balance between the outlay cost and the running costs. This system will not be the cheapest way to produce heating and hot water nor the most expensive installation system but a balance related to the existing equipment and personal requirements.   BEST ADVICE: Read the manual of the product you are proposing to use BEFORE you buy, especially regarding the installation and check that it will work for you.   Choosing the ASHP: The s

Marvin

Marvin

Heating and cooling assumptions.

An Excel spread sheet has been used to calculate the heating and cooling.   One thing also calculated is that at peak energy the bungalow requires as much for the heating in the winter as for the cooling in the summer! So the hottest part of the hottest day and the coldest part of the coldest night need about the same amount of power! This is mainly because of the solar gain through the windows.   The calculations were compared with what has been used for heating and it is re

Marvin

Marvin

Assessing heating/hot water energy prior to Combo

Following  1 I try to detail the info so people can check...   The bungalow ran on LPG bottled gas for 3 years heating and hot water so I know what was used: I have used the worst 2 years:   I am using the conversion rate of  one kg of LPG gas giving about 14.091kW hours   In 2 years we used about 13277kW of LPG energy for heating and hot water. ( about 10 bottles of 47kg ) If we deduct a modest 2kW for ho

Marvin

Marvin

List of equipment being installed

The holistic set I am installing is:   ASHP main parts: : Air to water Cool Energy inverTech Air Source Heat Pump CE-iVT9 4.3kW-9.5kW Cool Energy 60L Stainless Buffer Tank CE-B60   MVHR main parts:  Domus HRX2-D Heat recovery System with "summer bypass" 125mm and 150mm rigid circular ducting and Domus duct insulation.     Electricity Generation main parts: PV Sofar Solar Grid Tied Inverter 6KTLM-G2 16 Longi  320W Mono Solar Panels

Marvin

Marvin

Bungalow air tightness

Air tightness was followed to a reasonable standard:   All external walls sealed with plastic before the electric first fix   Plasterboard ceiling to almost floor and then siliconed / masticed to floor.   No open fireplaces, cat flaps or tricklevent.

Marvin

Marvin

Bungalow thermal elements

The bungalow has an average of 180mm of PIR under the suspended floor. The cavity walls have an average of 140mm PIR in the walls The loft has an average of 300mm of fluffy. Theflat roof has 200mm PIR. The doors and windows are the latest double glazing.

Marvin

Marvin

Bungalow history

The bungalow was built in the 1970's and extensively renovated in the last 4 years.   It has external block walls and timber suspended floor, timber frame including all internal walls and concrete tiled roof running east/west at a rise of 23 degrees.   Having never heard of, or gained knowledge from, buildhub I renovated and extended the bungalow as best as I knew. The garage was converted and has a flat roof. Fortunately the work included insulation, air tightness and a MVHR

Marvin

Marvin

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