Vol 7:2 Air Source Heat Pumps: Good Idea for Manitobans?

Short answer: no.

And yet, air source heat pum

ps are being flogged by government agencies and various local heating companies as effective in affordably increasing the energy efficiency of Manitoba homes.

There is even money being made available by both provincial and federal sources - Efficiency Manitoba and Greener Homes, respectively - to offset the cost of installing a heat pump.

How Heat Pumps Work Furnaces create heat. Heat pumps do not. Instead, they absorb and transfer heat.

Air source pumps absorb heat from the air inside and outside your home to raise or lower its indoor temperature. (Ground source heat pumps – commonly referred to as geothermal heat - facilitate the same process, but between the air inside your home and the ground outside of it.)

To raise the temperature in your home, the air source heat pump absorbs heat from the air outside and transfers it inside. To lower the

temperature, the unit absorbs heat from inside your home and transfers it outside.

There are 2 types of air source heat pumps – regular and cold climate. The cold climate unit is not cold climate enough for Manitob

a, however.

Why Even the Cold Climate Air Source Heat Pumps Fail in the Manitoban Climate The 2 local area heating technicians I spoke with – one from Furnaceman and the other from Balcaen & Sons - both said that the cold climate air source heat pumps stopped working efficiently anywhere between -17 to – 22 degrees Celsius and were really only an asset in what they called the “shoulder seasons” – spring and fall.

What happens in the colder te

mperatures wipes out any gains made in the shoulder seasons. Here’s how it was explained to me:

At lower temperatures, humidity collects and freezes on the surface of the heat pump’s coils and although the unit has a defrost cycle which is designed to melt this ice, the heat pump cannot deliver heat while in defrost mode and – double whammy - the energy required to melt the ice is significant, potentially erasing the energy savings generated by using the unit in warmer temperatures.

Both technicians had stories of installing heat pumps in Manitoba homes only to be asked by the homeowners to remove them the following year.

Given how much media exposure the push to install these heat pumps has been getting, this information came as quite a surprise. In fact, as I write this, I am listening to someone on CBC's The Current claim that cold climate heat pumps work efficiently even in temps of -30 degrees celsius. Arghh - do your homework people!

I reached out to a local subcontractor for Efficiency Manitoba for clarification and what he told me surprised me even further - apparently the federal government is only just now talking about doing the research on the efficacy of air source heat pumps in Manitoba. That's just annoying. I know the rush is on to save energy but in these inflationary times when our consuming dollars are so squeezed, we can't afford to be making avoidable mistakes like this.

The Bottom Line: if you can afford it, the ground source heat pump is currently the only reliable option for Manitobans until air source heat pump technology improves

Wendy Peters, Real Estate Broker Winnipeg, Manitoba