HVAC is a tough space for paid ads - tonnes of high-intent searches, but also a tonne of competition the second someone's AC dies in the middle of a heatwave. Before you or your brother spend a single pound, there are a few things I've seen make or break campaigns in this vertical.
First, get the Google Business Profile set up and verified properly. For a local HVAC business, that profile is gold - a solid chunk of leads come straight through Maps and the local pack, and it costs nothing. Reviews matter more than you think. Start collecting them now, even if you're not running ads yet.
Second, Local Service Ads (LSAs) are honestly where I'd put the first money. You pay per lead, not per click, and they're built for exactly this type of service business. He'll need to pass the background and licence checks, but it's worth the hassle. Just be aware LSAs tend to pull in service calls, not new installs.
Call tracking is non-negotiable. Most HVAC leads are phone calls, not form fills. If you can't track where the calls are coming from, you're flying blind. don't even think about running Google Ads without it.
Speed of response is huge, especially for LSA. Picking up the phone within a few seconds actually helps Google favour your ad. I've watched campaigns perform terribly simply because nobody answered when the phone rang. Make sure your brother has a system for that.
For standard Search ads, keep keywords tight and local - "AC repair [city]", "furnace repair near me". Use exact and phrase match, and pile on negative keywords from day one to keep out DIY searchers. If you don't know what a negative keyword is, get advice before you start spending.
LSAs and a basic Search campaign are doable yourself, but I've seen more money wasted than a consultant would've cost. If you do hire someone, make sure you own the Google Ads account. if they want to run it from their account - walk away. That's a red flag every time.
Hope that helps, it's a lot to juggle but getting those foundations right changes everything