Heat Pump w/ Gas Boiler Baseboard Heat Backup
The various installers who have provided quotes have talked about a "hybrid" system which would seem to indicate that it is possible; however, I am struggling to understand the specifics.
I have asked them but given the heat/humidity of late in Massachusetts, my interaction with them has been limited.
I have been proposed Lennox EL18XPV and American Standard Platinum 20
Comments
-
You could just manually turn on your boiler and turn off the heat pump when you feel like it's not keeping up (or you've figured out the cross-over point where it would be cheaper / more efficient to operate). Alternatively, you could just set the thermostat for the boiler very slightly lower than the heat pump is set at, so that it would automatically kick in. They also make thermostats that can switch over to an auxiliary heat source if the main one can't maintain the temp after a certain point.0
-
Hi, thanks for the feedback.fentonc said:You could just manually turn on your boiler and turn off the heat pump when you feel like it's not keeping up (or you've figured out the cross-over point where it would be cheaper / more efficient to operate). Alternatively, you could just set the thermostat for the boiler very slightly lower than the heat pump is set at, so that it would automatically kick in. They also make thermostats that can switch over to an auxiliary heat source if the main one can't maintain the temp after a certain point.
Looking at the Lennox S30 and the American Standard XL1050 (proposed thermostats), it seems like both can control the heat pump and an auxiliary backup heat source. What's not clear to me is if this includes a conventional hot water gas boiler. They mostly seem to talk about gas furnaces and not much about gas boilers. Both are controlled via 24VAC so I'm not sure why it would be an issue.
My preference would be a single thermostat for the whole system like the S30 or XL1050.1 -
Probably set up the T-stat determines when to use the
heat pump
back up
and emergency heat.0 -
Not really. The two normally are set to a different number of cycles per hour, so if you can't set that for the boiler that could be a bit of a nuisance, if not a problem.JustinS said:
Ideally, yes... any reason why a conventional gas furnace would be supported and a gas boiler wouldn't be?pecmsg said:Probably set up the T-stat determines when to use the
heat pump
back up
and emergency heat.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
I'm not 100% sure but I think that the CPH settings for the XL1050 and S30 are for the heat pump.Jamie Hall said:
Not really. The two normally are set to a different number of cycles per hour, so if you can't set that for the boiler that could be a bit of a nuisance, if not a problem.JustinS said:
Ideally, yes... any reason why a conventional gas furnace would be supported and a gas boiler wouldn't be?pecmsg said:Probably set up the T-stat determines when to use the
heat pump
back up
and emergency heat.0 -
Then you have a single point of failure, the thermostat. Redundancy. Two stats, two fuels, two heating appliances. Might save you a lot of grief if you go away for a vacation in in the winter.JustinS said:My preference would be a single thermostat for the whole system like the S30 or XL1050.
0 -
Hmmmm, good point...WMno57 said:
Then you have a single point of failure, the thermostat. Redundancy. Two stats, two fuels, two heating appliances. Might save you a lot of grief if you go away for a vacation in in the winter.JustinS said:My preference would be a single thermostat for the whole system like the S30 or XL1050.
0 -
Thermostats are pretty reliable. The batteries inside them, terrible. Happened to me last winter, came home to a 40 degree house.0
-
-
I'm not familiar with the thermostats you listed, but staging is done though it. As long as everything is wired correctly.
Have you looked into 2 stage heat pumps? You could potentially have 2 cooling stages and 3 heat, with stage 3 being the boiler. That's pretty much my plan when it's time to replace my AC. I'm swinging between 2 stage and inverter. I'm leaning towards the KISS method.0 -
Since installing a heat pump and the controls are powered off the air handler the old T87 is no in the boiler room wired into the boiler as a back up!WMno57 said:
Then you have a single point of failure, the thermostat. Redundancy. Two stats, two fuels, two heating appliances. Might save you a lot of grief if you go away for a vacation in in the winter.JustinS said:My preference would be a single thermostat for the whole system like the S30 or XL1050.
0 -
I hadn't really considered 2 stage heat pumps, both installers started with variable capacity ones.HVACNUT said:I'm not familiar with the thermostats you listed, but staging is done though it. As long as everything is wired correctly.
Have you looked into 2 stage heat pumps? You could potentially have 2 cooling stages and 3 heat, with stage 3 being the boiler. That's pretty much my plan when it's time to replace my AC. I'm swinging between 2 stage and inverter. I'm leaning towards the KISS method.
The whole endeavor began with what will be able to properly condition my 2nd floor (uneven cooling now due to orientation of the house along the lines of +7 degF back vs front). There will be zoning to address this unevenness from solar radiation.0 -
JustinS said:
I'm not familiar with the thermostats you listed, but staging is done though it. As long as everything is wired correctly.
I hadn't really considered 2 stage heat pumps, both installers started with variable capacity ones. The whole endeavor began with what will be able to properly condition my 2nd floor (uneven cooling now due to orientation of the house along the lines of +7 degF back vs front). There will be zoning to address this unevenness from solar radiation.
Have you looked into 2 stage heat pumps? You could potentially have 2 cooling stages and 3 heat, with stage 3 being the boiler. That's pretty much my plan when it's time to replace my AC. I'm swinging between 2 stage and inverter. I'm leaning towards the KISS method.0 -
Zoning as in Duct dampers or as in separate systems?JustinS said:
I hadn't really considered 2 stage heat pumps, both installers started with variable capacity ones.HVACNUT said:I'm not familiar with the thermostats you listed, but staging is done though it. As long as everything is wired correctly.
Have you looked into 2 stage heat pumps? You could potentially have 2 cooling stages and 3 heat, with stage 3 being the boiler. That's pretty much my plan when it's time to replace my AC. I'm swinging between 2 stage and inverter. I'm leaning towards the KISS method.
The whole endeavor began with what will be able to properly condition my 2nd floor (uneven cooling now due to orientation of the house along the lines of +7 degF back vs front). There will be zoning to address this unevenness from solar radiation.0 -
2 CAC systems, there will be 3 zones in total... 1 downstairs on one unit, 2 upstairs on another unitHVACNUT said:So you're going mini splits, or 2 CAC systems?
Duct dampers on the 2nd floor, none on the 1st as it's pretty open floor planpecmsg said:Zoning as in Duct dampers or as in separate systems?
0
Categories
- All Categories
- 86K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 52 Biomass
- 421 Carbon Monoxide Awareness
- 81 Chimneys & Flues
- 1.9K Domestic Hot Water
- 5.3K Gas Heating
- 96 Geothermal
- 154 Indoor-Air Quality
- 3.3K Oil Heating
- 60 Pipe Deterioration
- 893 Plumbing
- 5.9K Radiant Heating
- 379 Solar
- 14.7K Strictly Steam
- 3.2K Thermostats and Controls
- 52 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements