Published by CSA Group in , 96 pages Withdrawn The F Standard is intended to provide architects, home builders, heating and cooling contractors. CAN/CSA F (R). Determining the Required Capacity of Residential Space Heating and Cooling Appliances, Includes Update No. Frs|uljkwhg#pdwhuldo#olfhqvhg#wr#Xqlyhuvlw|#ri#Wrurqwr#e|#Wkrpvrq# Vflhqwlilf/#Lqf1#+zzz1whfkvwuhhw1frp,1##Wklv#frs|#grzqordghg#rq#
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Over the last 15 years, energy use in new homes has been reduced by nearly 40 per cent. Voluntary, market-driven programs like EnergyStar, Built Green and R have provided builders with the technology and construction practices needed to build more comfortable, healthy and efficient homes.
Today, we have building codes that require increased insulation values, mechanical efficiencies and air tightness. In many provinces, a new home built today delivers the energy performance of R homes built in the early s.
Heat Loss/Gain Software Development for CSA F280 Standard
One very direct consequence of these changes is that heating and cooling loads have dropped substantially in new homes across Canada.
This can, and does, cause problems for builders. An unintended consequence of using the old CSAFM90 standard when designing HVAC systems for today’s new homes is chronic over-sizing of heating and cooling equipment, as well as over-sizing of air duct delivery systems.
Within the industry it’s well known that oversized systems in new energy efficient homes often result in comfort issues for occupants and can lead to homebuyer complaints and warranty claims. Somewhat like putting shoes on a child that are too big, oversized HVAC systems result in homes that run “sloppily” and inefficiently. Depending on a home’s layout, short cycling of HVAC equipment can lead to cold rooms on the second floor, and in rooms over garages with exposed floors.
During the cooling season, the problems change, but include poor thermal circulation and inadequate dehumidification. Short cycling also results in decreased mechanical efficiency, f820-m90 compromises the performance capacity of today’s more efficient heating and cooling equipment.
These problems can be avoided by the use of the new CSA F standard. It provides a tremendous opportunity for homebuilders and f28-0m90 HVAC industry to rationalize new mechanical system design. Here is a brief synopsis of the more critical changes. The calculation method can now accept objective airtightness indicators cas as blower door air tightness tests.
This will be important in both new and existing homes where energy audits or specific air tightness targets have been verified by site testing. The interaction between different types of ventilation systems and air leakage is accounted for.
Standards Council of Canada
For example, a home with an exhaust-only ventilation system creates a slight negative pressure that changes the leakage patterns in a home and the new standard makes allowance for this. In the old Standard the total heat loss for the building was assigned to individual rooms as a function of the heat loss of that room.
In the new Standard, recognition of the stack effect warm air rising in a home will mean that the assignment of air leakage heat loss will be a function of the floor level of specific rooms. In other words, rooms on the first floor of a home will be assigned a greater portion of the air leakage component. The U factors and solar heat gain coefficients reported by window manufacturers in their CSA A compliant labeling can be directly put into the calculations now.
Finally, the new Standard will allow designers to take credit for the impact of heat recovery ventilation devices employed in a home. The new Standard will result in more accurate and potentially lower load calculations given the efficiency changes in new homes.
Home BUILDER Canada – THVAC Optimization: Bigger Isn’t Always Better
In applying the new Standard, designers and mechanical contractors will need to recalibrate old “rules of cam for sizing equipment in today’s new homes: Equipment with optimized controls could be more compact, programmed to operate at peak efficiency over longer cycle times and make use of newer and extremely efficient fan motors and pump controls. Smaller loads with traditional forced air systems require reduced fan capacity.
The delivery systems i.
The new Standard is formally recognized by the Ontario Building Code as of January 1,and is expected to be referenced in the National Building Code of Canada in the near future. In f280–m90 last two years, the new Standard has been applied on multiple Net Zero projects across Canada with great success. Occupants of these Net Zero houses are raving about the “comfort” of their homes.
Besides being quieter, and often smaller, “right sized” equipment delivers ambient temperatures which are nearly identical on every floor and in every room.
The mechanical systems also operate at peak efficiency further reducing the cost of operation. The new CSA F Standard results in more accurate and potentially lower load calculations that reflect the efficiency improvements in today’s 2f80-m90 homes. The table illustrates the results of applying both the old and new standard to a reference home assumed to have an HRV air tightness of approximately 2.
He may be reached at andy buildingknowledge.