One other trend that is emerging right now is dual fuel systems which combine an air source heat pump with a small gas furnace.
Such technology can let homeowners have the capability to make decisions based on fuel costs, performance, and future carbon taxes.
Heat pump technology is currently gaining in their popularity thanks to their increases in cold weather performance, as well as the chance for builders to provide a totally electric solution that cuts out the need for a building to have a gas line run into it.
Looking closer at combination systems for water and space heating quickly shows that both research and development labs as well as governments have all been intently looking at such systems for a while now as a good way to start meeting the needs of low-energy homes.
A recent Canadian Gas Association study that compared high-performance combo system to a regular heating system that had a storage tank water heater and high-efficiency furnace.
This testing was done in both February and March of 2016 in Ottawa at the Canadian Centre for Housing Technology, or CCHT. The location was used because it has a pair of identical houses, one a test house and the other a reference house. Both of the houses were built compliant to R-2000 standards. The houses feature simulated occupancies that are deliberately identical and see extensive monitoring for thermal comfort and energy performance. The test house in this study used a 15-150 MBH-rated condensing tankless water heater, sporting an 0.97 EF with a 73-MBH rated air handler. The reference house had a mechanical system based around a 96.3% AFUE with a 2-stage 25-40 MBH furnace, partnered with a 40 MBH 40 U.S. gallon power-vented 0.62 EF storage tank water heater.
The test ran for a month, and the results demonstrated that the combination system wound up outperforming the reference house by using roughly 4% less total energy.
These results mean that combo systems show promise, which might mean that they have more future use in low-energy homes that have lower heating loads but larger DHW loads.
CCHP stands for cold-climate air-source heat pumps, which are another technology choice that many R&D labs and governments are also studying. CCHPs offer an all-electric and efficient solution for smaller AC and heating loads, which low-energy builders find appealing. The market penetration of air source heat pumps has been hampered by the previously limited effectiveness of them, given the cold outdoor atmospheric temperatures that many parts of Canada experience. Low-temperature heat pumps might change all that. NRCan CanmetENERGY research authorities at the time of writing have a five-year strategy for CCHP technology, complete with programs for R&D and field verification. The hope is to get CCHPs to be even more effective than before at the lower temperatures many Canadians experience.
The hope is to also make them more affordable, as well as a way to reduce more carbon emissions since they run only on electricity.
The average home actually loses anywhere from 20 to 40 percent of its air as it moves through the ducts, because of kinks, poor connections, punctures, and leaks. Issues like that can mean you suffer higher utility bills, poor air quality, rooms that are stuffy and uncomfortable, and even difficulty heating or cooling rooms. If you get your HVAC duct system cleaned and then sealed, it adds a great many benefits when it’s done right.
The following is a checklist of 5 specific improvements that might need to be done to your home’s duct-work:
1) Repair or replace any ducts that are damaged, improperly sized, or poorly connected.
2) Straighten out or replace crushed or tangled flex ducts.
3) Seal all seams, joints, and connections with duct tape or liquid duct sealer.
4) Tightly seal all registers and grills.
5) Insulate ducts in crawl spaces, attics, and other unconditioned areas with insulation with high R value insulation.
The combination of a high efficiency heat pump, a gas furnace and a cleaned and tightly sealed duct system is certainly one of the top efficiency systems and becoming more and more popular with rising utility costs.