Best Of
Re: Another glitch on a steam install
It’s also piped wrong with the main tapped between the risers.
Ironman
Re: Tomorrow is Install Day!
Had to make another quick climb up to install the correct rain cap as they sent the wrong diameter one.
All the ladders are put away. Job done!
Yesterday I removed our coal boiler and started the clean up of the area. Now I will get the new Weil-McClain into position and see how I want to position it and the indirect hot water tank.
Re: Chilling me softly with
Really interesting @hot_rod, we're running a similar trial in our showroom in London. We've been keeping the flow temp just above dew point. It has had a modest cooling effect but the ∆T is so small between ambient and water temp that the we're talking a degree or two of cooling effect. We'd need to add condensate drains and chill the water further, and introduce fans to move the air around in order to get more siginificant cooling.
Would love to hear how you're getting on a month on. Has it had a significant effect? What were the ambient, flow and return temps? What emitters are you using? Is this a radiant floor?
Re: AWHP - Plate heat exchanger or not?
I have an Arctic heat pump, and Spacepak fan coils (which are really just Phnix units from China). When I was shopping 3-4 years ago there wasn't as many options as there are today, but the Arctic has been running well. Their controls are not very good, I use a HBX heat pump controller instead of the factory controller. I'm guessing the Viessmann at least will have much better controls built in. I'm not thrilled on the Spacepak fan coils, the controls are also not very good and I have replaced two 24V transformers in the last 2 years…
If you are interested I have a bunch of videos on my system on Youtube, I did this DIY with some help from my local Arctic rep. Lots of learnings, but we are overall happy with how it all works.
https://www.youtube.com/playlist?list=PLl00MrbmZuKLKTqNBk_HueAszsW1A5CbQ
devvar
Re: AWHP - Plate heat exchanger or not?
I am having this same debate with myself. I have an AWHP system that currently services a portion of my house, with the eventual goal to expand the system to cover my whole house. I currently have the entire system filled with glycol. While this has worked OK for the last couple years, I am considering installing a heat exchanger and switching the indoor portion to water for the following reasons:
- I have had one leaky fitting on a fan coil in a bedroom. Thankfully it was minor, I caught it quickly, and the bedroom floor is vinyl so nothing was damaged. But its a lot easier to clean up water than glycol if a leak occurs. A catastrophic failure would result in not only a mess to clean but also require purchasing more expensive glycol
- I don't want to deal with draining and storing up to 100 gallons of glycol if/when I need to add or replace a component
- One of my fan coil emitters is pretty undersized, the reduced heat transfer of glycol is not helping this situation, especially in cooling season when the glycol becomes more difficult to pump due to low temp and I'm losing both flow rate and heat transfer
I'm not a professional, just a guy who has been living with this for a few years and wants to make my life as simple as possible to add, repair, or replace components as needed. My understanding is that if the heat exchanger between the inside and outside loops is sufficiently sized the efficiency loss in the exchanger will not be much different than the efficiency loss of using glycol throughout the whole system
devvar
Re: AWHP - Plate heat exchanger or not?
glycol flows better than water so will leak more readily. Glycol needs to be maintained or it will become corrosive and damage system components.
mattmia2
AWHP - Plate heat exchanger or not?
Hello,
I'm looking at options for air to water heat pump systems. This would be for space heat and DHW using a reverse indirect buffer tank.
Some manufacturers system designs call for the AWHP to directly heat the buffer tank, with the entire tank and hydronic zone loops being glycol mix. Other manufacturers (US Boiler) suggest a plate exchanger between the AWHP and the buffer tank, with glycol only in the outdoor heat pump loop.
If I understand, the pros for the exchanger are:
- Less glycol. A buffer tank worth of glycol mix isn't cheap, and if you need to drain the system, you would need to deal with all of that mix.
- Better heat transfer / easier pumping in the hydronic zones and indirect tank without glycol.
Cons:
- More parts: heat exchanger, additional circulator, valves, etc. Probably eat up the cost of glycol savings.
- Loss of efficiency through the exchanger, critical to get flow rates / Delta T correct.
Thoughts?
Thank you.
Mark_R