Boilers are chosen for efficiency, low maintenance burden and local representation/parts availability:
- For our favorite low-mass, modulating/condensing boiler, go to:
Fire-tube heat exchangers tend to burn clean and require less maintenance. The WHN-series boiler has plain English programming and a good interface. This is our most common installation for low temperature radiant systems.
- For a higher-mass, sealed combustion, cast-iron boiler ESC-series, go to:
Many folks (including ourselves) still see the benefit of a well-made, high-efficiency, high-mass, 40+ year lifespan boiler. We suggest these units for two temperature systems where we might have low temperature radiant and higher temperature towel warmer radiators. There is a good argument that these boilers have as low a “lifetime operating cost” as any mod/con boiler. Ask us why we like cast-iron!
Indirect fired water heaters for boiler and boiler backed-up solar domestic water heating are chosen for price, local availability and 316L stainless tanks and heat exchange coils:
- https://www.heat-flo.com/ We like these units because the taps are on the top of the tank, allowing a more compact installation. Otherwise there is not a qualitative difference between this and other tank brands.
- http://www.htproducts.com/literature/SuperStor_Pro_Brochure.pdf Heat Transfer Products also makes some good tanks
For hydronic geo-thermal heat pumps, the inverter driven WV 060 is hands down the best on the residential market. Heat pump heating performance is measured by their “co-efficient of performance” or COP. This is a measure of how many kilowatts of heat energy they pump from the ground per kilowatt of electricity used to run the heat pump. While other high quality hydronic are rated at a nominal COP of 3.1 and might peak at a COP of 4.9, the WV 060 runs at a nominal COP of 3.1 and peaks at a COP as high as 6!
Solar Collectors, the SunEarth empire series collectors are among the best on the market.
We prefer circulators by Grundfos, and other system components by Caleffi, Webstone and Amtrol.