Air source heating pump
Discussion
we have recently moved into a new place which has an air source hearing pump...it’s an air to water system. It’s used for hot water and heating, we have underfloor heating downstairs and rads upstairs. The house is about 2000 sq ft.
The problem is that I am not sure we are using it right.
In our old house which was about 1500 sq ft we had a gas boiler, and underfloor...we paid about £70 a month for electricity and gas. We’ve been in the new place for 6 months so mostly in the summer months with no heating on, just hot water and it’s almost double the cost at £120 a month...I’ve got a fear on how expensive it’s going to be in the winter!
I’ve got it set up so the hot water comes on for about 3 hours split through the day. The heating is on for a couple of hours in the morning and a bit longer in the evening.
I thought these systems were supposed to be pretty cheap to run....am I doing something wrong?!
The problem is that I am not sure we are using it right.
In our old house which was about 1500 sq ft we had a gas boiler, and underfloor...we paid about £70 a month for electricity and gas. We’ve been in the new place for 6 months so mostly in the summer months with no heating on, just hot water and it’s almost double the cost at £120 a month...I’ve got a fear on how expensive it’s going to be in the winter!
I’ve got it set up so the hot water comes on for about 3 hours split through the day. The heating is on for a couple of hours in the morning and a bit longer in the evening.
I thought these systems were supposed to be pretty cheap to run....am I doing something wrong?!
280E said:
Which model of ASHP have you got? What flow temperature do the upstairs rads run at?
Unless your house is very, very well insulated, an air source heat pump may not be the best solution. Their efficiency also drops off at low air temperatures - just when you need it the most
Honestly not sure, I know it's a Mitsubishi,,,looking at the net it might be an Ecodan? I'll wonder out this morning and see if I an see anything that identifies the model. As for flow temps again no idea really...I can feel the underfloor heating on downstairs, but the upstairs rads seem to be cold all of the time, or at very best slightly warm to the touch. The house seems to warm up OK, although I suspect all of the heat is from underfloor rising through the house.Unless your house is very, very well insulated, an air source heat pump may not be the best solution. Their efficiency also drops off at low air temperatures - just when you need it the most
The house was built in 2009 so not that old and I think it's fairly well insulated....but no unfortunately they didn't bring gas up to the house when it was built...I am told it runs along the road which is maybe 10m from the front of the house...so I would guess we would need to pay for a trench and then connecting the house up, plus a boiler....I am guessing at anything between £5k-£10k to convert it. Looking at how much the ASHP is costing in running costs plus servicing I could be looking at 5 years to break even if I swapped.
Equus said:
I've done estates around that date, with heating systems based on the Mitsubishi Ecodan, built to Code for Sustainable Homes Level 4.
The worst of the complaints we received were from people who - like you - used them intermittently.
I'm not a big fan of heat pumps, all round, but they really don't work well or efficiently if they're switched off most of the time whilst people are out at work/asleep and are then called upon to ramp the temperature very quickly in mornings or evenings.
You could try managing the system differently, so that it is running continuously, at a low level - see if that improves the situation?
Ok I've had a look and it's a Mitsubishi Zubadan...so I guess it's maybe an older model?The worst of the complaints we received were from people who - like you - used them intermittently.
I'm not a big fan of heat pumps, all round, but they really don't work well or efficiently if they're switched off most of the time whilst people are out at work/asleep and are then called upon to ramp the temperature very quickly in mornings or evenings.
You could try managing the system differently, so that it is running continuously, at a low level - see if that improves the situation?
Happy to change it around and run it for longer and see if that helps improve how well it works...what makes most sense? Have it on for all day or something?
Equus...thanks for taking the time to type that up, really interesting and much appreciated!
I may try setting it up for running longer in the day, checking how much power was used then rinse/repeat to see if I can improve it. The house isn't really that cold at the moment so it shouldn't be working to hard to warm the place up, I also think the dial thermostats are a bit rubbish so I am going to get those replaced with a couple of nest devices this week to see if that helps the situation at all.
What really shocked me was how much electricity was used in the summer when the heating was off...again it maybe because it was working hard to heat the hotwater up again.
Some experimentation required!
I may try setting it up for running longer in the day, checking how much power was used then rinse/repeat to see if I can improve it. The house isn't really that cold at the moment so it shouldn't be working to hard to warm the place up, I also think the dial thermostats are a bit rubbish so I am going to get those replaced with a couple of nest devices this week to see if that helps the situation at all.
What really shocked me was how much electricity was used in the summer when the heating was off...again it maybe because it was working hard to heat the hotwater up again.
Some experimentation required!
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff