Heat loss experiment

[Radian]

My recently built garage/workshop extension looks roughly like this:

 

The new glazed pavilion and floor above has been added on to our original workshop/garage. The intermediate gable was demolished at first floor level to create one large room above.

Regrettably the insulation levels are to building standards only, and no heating has yet been installed. I did put in a UFH loop in the ground floor screed in preparation though. Unfortunately this was all planned and constructed when energy costs were nothing like the major issue they are now.

 

Now I'm trying to figure out what kind of heating to put in to make it usable all year round, so I've been collecting data on the actual thermal performance comparing it with some rough heat loss calculations and I'm not sure if it all stacks up.

 

 

All I've done is very crudely worked out the fabric heat losses (the original cavity walls are more like guesses) and put in a 2kW digitally controlled heater set to 10C, monitoring daily power consumption vs. mean outside temperature. As shown above, the loss calcs suggest 10kWh for a 5C delta. The actual data agrees with this almost exactly but I'm suspicious! After all, there's no account taken for air exchange and there's been no other heat input during the monitoring as the place is currently unoccupied. Should I trust this experiment and base my heating decisions on it?

[IanR]

Air infiltration, will be a factor, but not substantial with  5° delta.

 

Solar gain might be with that glazing, depending on direction and insolation  levels

[Radian]

1 hour ago, IanR said:

Air infiltration, will be a factor, but not substantial with  5° delta.

 

Yeah, the biggest delta so far has only been 8 degrees. If I was using the place I would crank it up inside but I'm otherwise engaged at the moment. On the other hand, Nature may intervene for me in the coming months.

 

1 hour ago, IanR said:

Solar gain might be with that glazing, depending on direction and insolation  levels

 

Not much of a problem on the ground floor with glass facing NW/NE but it did get uncomfortably hot for a week or two upstairs this summer. 

[SteamyTea]

Did you calculate your HDDs or use https://www.degreedays.net/

 

Dorset is pretty sunny.

[Radian]

54 minutes ago, SteamyTea said:

Did you calculate your HDDs or use https://www.degreedays.net/

 

Dorset is pretty sunny.

 

Thanks, yes, I've used the online data before but for this particular rig I'm using modified Bluetooth sensors  logging into a DB along with various other indoor sensors.

 

 

I'm really quite chuffed with them as they're only £7 each and there's a Hacked firmware for them that allows the data to be transmitted using the BLE Beacon function. This can be intercepted using an ESP32 and logged over WiFi. This means you don't have to go anywhere near the smartphone app they were originally intended for.?