Q: For homes with existing hydronic (hot water) radiators, what do you recommend? Is it possible to use air-source heat pumps to heat the water on those systems? What about increasing the radiator sizes to operate with Lower water temperatures?
A: Yes you can do this. Daikin, Jaga and SpacePak all make air-sourced heat pumps designed especially for FHW systems. Rather than expand the size of the radiators, which will be very expensive and highly disruptive to your current rooms, I think it will be a lot cheaper to use the existing radiators and leave the old furnace in place in case the heat pumps can’t keep the place warm in the middle of winter. If you can’t keep the fossil-fuel furnace, you could also use a small electric fan heater to “top up” the rooms that don’t get warm enough in winter. This is a lot cheaper that replacing radiators. You can also get mobile floor-standing heat pumps that bring air in through a pipe that fits into a sash window that is partly open and sealed with an attachment that comes with the heat pump. These cost only about $750 and seem like a good deal to me, though I have not used one myself (yet – I intend to buy one a try it this winter in our rental property).
The highly-acclaimed book “Zero Carbon Home” by “Green Guru” David Green.
How we cut our home’s carbon emissions to zero.
How we cut our home’s utility bills to zero.
Solar panels on the roof of our house.
Our heat pumps.
Fiberglass and ISO board insulation on the roof of our house.
Triple-pane windows in our living room.
The Easiest Way to Calculate Your Home’s Carbon Footprint:https://greenzerocarbonhome.com/2018/07/what-is-the-carbon-footprint-of-natural-gas-heating-oil-propane-and-coal/
Written Answers to over 300 Questions about Zero Carbon Homes:https://greenzerocarbonhome.com/webinar-questions-and-answers/
Finance and Net Zero Energy Terms explained: https://greenzerocarbonhome.com/energy-and-finance-terms-explained/
Zero Carbon Home Website Home Page: https://greenzerocarbonhome.com
Database of State Incentive for Renewable Energy (DSIRE) https://www.dsireusa.org
Published articles on Zero Carbon and Net Zero Energy:
Department of Energy, EnergySage, “Zero Carbon Home”https://www.energysage.com/project/7230/zero-carbon-home/
Zero Energy Project, “My Zero Energy Retrofit beats my 401k”https://zeroenergyproject.org/2018/09/23/my-zero-energy-retrofit-beats-my-401k/
Cool Effect, “Mr. Green’s Zero Carbon Home” https://www.cooleffect.org/content/news/green-testimonial?utm_source=Cool_Effect_CRM&utm_medium=EMAIL&utm_campaign=20180814Engage_Testimonial&utm_content=green_CTA
Green Energy Times, “My Zero Energy Pool is a Great Investment!” http://www.greenenergytimes.org/wp-content/uploads/2019/05/GET_May-2019.pdf
Published Presentations on Zero Carbon Zero Bills:
To see a 3-minute interview of David Green by NBC Boston anchor Joy Lim Nakrin, please click here:TV interview
To see a 20-minute TED talk at Harvard Business School, please click here: TED Talk
You can watch a recorded version of my Zero Carbon, Zero Bills webinar here: Zero Carbon, Zero Bills Webinar
Reviews of my “Zero Carbon, Zero Bills” webinar included, “Minute-for-minute, point-for-point, one of the best webinars I have ever attended. Thank you!”, “David is a true inspiration and asset to our community. He inspired us to get solar panels and a new front door”, “This is like a masterclass in ZeroCarbon”, “Thank you soooo much for the sensible advice and your fabulous resources!!” and, although this next comment is a little flowery, it does express the sentiment of many other comments, “Your contribution to Greening America is great and will probably help our survival as a species a bit longer than expected”.