How to Add an Air Source Heat Pump to My Hot Tub

[@Buildahottub]

Air Source Heat Pumps and Connection Kits for DIY available here - shop.buildahottub.com/product-category/air-source-heat-pumps/

[@PaulDavis-wc6eb]

Great video… thank you. I am researching how to go about this at the moment, but will be in touch when I’m ready to progress.

[@kingmatthewa]

I was JUST thinking of this after your video on it. I had never hear of such a thing. Thanks for reading my mind, Andi!

[@Buildahottub]

You're so welcome!

[@anthonyshort3437]

If my circulation pump system was a low flow system of aprox 25mm pipe which other pump would you recommend piping into before or after the 2hp single pump or the 2 speed pump?

[@Buildahottub]

Hi Anthony, difficult to know without seeing what is where on the plumbing - shoot me over an email and I will take a look for you - andi (a.t) buildahottub.com

[@markjordan1530]

Hi Andi. I have a balboa unit and I’m looking to add the 12kw Duratech unit. Any ideas on where I can source the pipes, etc? I might be better getting it done by someone who’s done it before. I don’t suppose you can recommend anyone? I’m in Leicestershire. Thanks for this very useful info.

[@Buildahottub]

Hi Mark, thanks for the comment. Can you drop me a line on my email and we can pick it up on there. I can help with the parts and the heat pump you are looking for email me at andi (a.t) buildahottub.com cheers

[@Killerchihauhau]

Can u add a heat pump to a 2 person spa? I’m in the USA which do you recommend?

[@Buildahottub]

You can yes, but they are expensive in the USA as the demand for heat pumps is not like in Europe for example - I have a range on my site - you can the cheapest mode here - shop.buildahottub.com/product/hydro-royal-hr-110/

[@basilkearsley2657]

I’m using a hot splash air source heat pump rated for 3.35KW/h and it heats my 5 person hot tub from 21°C to 31°C in 5 hours. So 9KW/h is way overkill. Where do you buy the parts your taking about?

[@Buildahottub]

Hi Basil, depends on the volume of water, insulation R values and the external ambient temperature - I have a 21KW Air Source on my own hot tub, which is over specified but I like it that way - this is well documented on this channel. I supply any parts I mention - thanks for the watch and the comment, all the best Andi

[@martynbarnett2463]

Hi Andy... coming into this late, so apologies. I am looking to install a Heat Pump on my Swim Spa. When I look at the existing piping, I cannot add the new piping to the HP (easily) on the output side of the existing Gecko Heater because i'd have to cut the pipe after the gate valve and that means draining the spa (which I really don't want to do). I think I CAN cut the pipe on the INPUT side of the existing heater and add the new pipe run and the bypass valves etc to the HP. Is there a reason why i cannot put the HP AFTER the Circulation Pump, but BEFORE the Gecko Heater? thx in advance

[@Buildahottub]

Hi Martyn, you can put the ASHP on the suction side, you normally see a bit more of a temperature difference between the thermostat on the tub and the thermostat on the air source, that is the only difference really. Hope that helps - Andi

[@martynbarnett2463]

that's really helpful, thanks Andi... top man!@@Buildahottub

[@northernoz]

Have you ever seen where there is a solar, heat pump and electric combination? And if so or not what would be the issues of both heat pump and a solar unit ?

[@Buildahottub]

Hi Tony, Thanks for the watch and the comment. I have not seen a combo of Solar and Heat Pump before. I dont forsee any issues with the two of them working together in tandem. Or, you could even have an either or option plumbed in if you wanted to select which was doing the heating. Biggest issue with solar is when people want off grid tubs - its tough to generate and store enough energy to run jet pumps. If you are using this as a heating method and have plenty of sun, dont see an issue. Only downside is both these methods are not great in a cold (and dark) winter (their output drops) so it depends on your climate and if you are going for an all season tub. Hope that helps, cheers, Andi

[@addijad]

Thanks for the Video, this is exactly waht Im looking for. /i have a 1000lr tub with a Balboa pack. it has 3 pumps for the jets and a single pump for the filter/heater. the problem I have is the Heat pump would need to be 25 ft away from the tub. I would intend to fully insulate the hose/pipe but is this a little too far? Could I install a secondary water pump (switch via a 240v relay) from the existing pump to boost flow.

[@Buildahottub]

Hi Andy, Thanks for the message. I've actually just installed one this week on a friend's tub, similar setup to you (but 2 pumps and a circ) you can read about it here - buildahottub.com/how-i-added-an-air-source-heat-pump-to-an-existing-hot-tub/ - i'd love to help you with the heat pump and parts etc so please drop me an email from the contact page at the bottom of the blog post with your contact number and we can have a chat. I have a video to match the post going live tonight on the channel. The potential issue you have is the flow rate from your circ pump. It will have been sized to deliver enough water through the heater and back into your tub. Adding 50ft (there and back) might overdo it. I wouldnt over complicate things with a slave water pump. I would fit it to the tub and if you get a flow error, swich out the circ pump for a larger one, they are not too expensive. This is easier than trying to get a water feed into a slave pump. - hope that helps

[@addijad]

@@Buildahottub Thanks for replying, Ill drop you an email,

[@martynbarnett2463]

Another question if I may... I don't understand why we don't have to disconnect the electrical supply to the existing heater.. if we don't, and we just reduce the Set Temp on the Spa so the heater doesn't turn on, that will also stop the circulation pump and therefore stop the flow through the Heat Pump.. right? So surely we HAVE to disconnect the heater, or we'd always have BOTH Heat Pump and Heater running, which surely defeats the object of having a HP ?

[@Buildahottub]

You do disconnect the heater yes, that is what I have done on my own tub - some people do leave it connected and use both (although you wont make as big of a saving there). I actually have it on a switch so if I need a boost in really cold weather I can tap into the electric heater too. Hope that makes sense - Andi

[@Ms2Chill]

I have a question, but unsure of how feasible it is after watching some of your videos. Is it possible to buy a cheap hot tub with like 24-35 jets, then take the top part (the part you sit in) off and use quality pvc for all the jets, and place the whole assembly into an icf framed space so that its air tight below the water above? Then use pumps, blowers and heater just like a concrete/block in-ground diy spa.

[@Buildahottub]

Thanks for the comment - not sure why you would go to the trouble to take it all apart? Why not just sink the cheap hot tub? They have instulation in the cabinets anyway and they can go in ground, you just need to have access to the control panel. A little confused on this one sorry.

[@Ms2Chill]

@@Buildahottub interested in this way because the consensus I'm getting online via reviews is that the tubs use too much electricity, can't use gas, start to break down after like 5-7 years etc. Where as if it was the diy version or others, you can use separate parts and ensure quality and durability. The basic hot tub is essential for just the jets and the smoothness of the tub surface. Hope that clarifies things

[@jasonmorgan5965]

4kw heat pump would suffice , 20kw heat pump is massive !

[@Buildahottub]

Thanks for the message Jason and of couse the video watch. Not sure I 100% agree with you here. Yes, 4KW would be fine however, that does assume 100% efficiency and 4KW being outputted all year round. Depending on the temperature rating of the pumps, even the best all seasons will drop output by 2/3 in cold weather. Therefore, starting with a large pump, outputting a lot of KW, you are going to have a good amount of heat all year round - perhaps I should have clarified that the video - have a great day - Andi

[@jasonmorgan5965]

@@Buildahottub Hi thanks for the reply 👍🏻 Larger than required heat pump would keep cycling on/off - on/off this reduces efficiency & costs more to run . Unless it is an inverter . Therefore a smaller heat pump working hard does not cycle as much & is more efficient / cost effective. This is how they should operate.

[@markrainford1219]

@@jasonmorgan5965 yes that's my thoughts also. Heat pumps are designed to run for long periods, not stop start. I suppose what you really need is data on your electricity usage of your own hot tub over twenty four hours in winter and summer. you can then accurately size a heat pump.

[@martinsmith4943]

@@markrainford1219 Additionally you have to power the heat pump. A 10kW heat pump can usually be run from a 13 amp spur, anything more than that will require its own feed from the fuse box; another argument perhaps for NOT running the heating element as well as the heat pump. One idea might be to power the heat pump from the fixed element supply instead of the element. That way the temperature control will all still work but you can size your heat pump at up to three times the power of the fixed heating element without overloading the existing supply.

[@martinsmith4943]

One further thought - I have been running a heat pump on my softub for two years; the heat pump I have is ineffective below 10 degrees ambient