Underfloor Heating Systems and Cold Weather
Underfloor Heating Systems and Cold Weather – Why aren’t I Warm Enough?
Whilst we’re all dreaming of warm summer days and the easier jobs that seem to come with it; there’s no doubt that the dreaded cold weather is good for business. As an industry, I think we have developed a love/hate relationship with freezing conditions. On the one hand, it’s good to be busy and get the money rolling in, and on the other, there’s frozen pipe emergencies and unrealistic customer expectations. Can we ever win?
Over the years, I’ve noticed that many of the customer calls I receive during the winter months have a similar theme when it comes to underfloor heating. Why aren’t I warm enough? Why isn’t my system heating the house like I thought it would? I understand the customer’s frustration. They have invested in a system and want it to perform – it’s not unreasonable to want to be a toasty warm 25 degrees inside whilst it’s minus 6 outside is it?
I’m sure, like me, you’re secretly rolling your eyes at the thought of explaining that whilst modern underfloor heating systems are excellent at generating high heat outputs they don’t have infinite capacity. They are influenced not only by how well they are installed but also by the type of house in which they are installed.
The current trend for new-build constructions aiming to achieve a net-zero carbon footprint means that these new buildings are so well insulated that a whole home could be heated from a candle. Okay, it’s an exaggeration, but you know what I mean. However, there is a big difference between these new builds and a ‘normal’ British home. The majority of owner-occupied dwellings in England were constructed in 1980 or before, and as of 2019, more than three million owner-occupied houses were built before 1919. That means that most homes in the UK could lack the insulation that will allow the newly installed underfloor heating system to meet the homeowners’ expectations.
To help you overcome any challenges you might encounter, I’ve listed below a couple of helpful tips to help you explain to a customer about the limits of a ‘normal’ house and their underfloor heating system.
- The heat loss. Depending on how involved you get with a job, we always recommend that heat losses are assessed and carried out for each property. Trying to implement current industry guides and best practices will not work on a pre-1950’s property due to the nature of construction.
- Customers need to understand that their underfloor heating system has been sized to operate in a way that mitigates the heat losses from the property based on a particular outdoor temperature. However, suppose the actual external temperature drops well below that used in the calculations. In that case, the UFH system may not maintain, and certainly not increase, the indoor temperature past a base temperature.
- Advise your customer on the best running practises for their underfloor heating system. Our previous article “How You Should Run Your UFH System” can be used to help explain the benefits of running the system all the time and reduce the amount of off time.
- The heat source. The most significant issue we see with an air source heat pump (ASHP) is the unit freezing in cold weather. This is because the potential energy outside is limited (by the cold temperatures), meaning that when we put a massive load into it, to heat a whole heating system, the unit goes into a defrost cycle. The air source heat pump then starts using your generated energy to defrost itself. Again, this hits home the importance of the article above and running the system content, especially on ASHP. Remember that an ASHP might not be the right decision for high heat loss houses.